BY DICK TURNER

A chronological account of the development of treasure and gold locators from 1830 to 1930.

 

As all gold hunters know, we are blessed with high-technology instruments to aid our searches for precious metals. Nuggets can be identified in a highly mineral matrix, thus eliminating unnecessary digging of unwanted material, and the Goldspear will locate even gold dust. However, none of these sophisticated detectors appeared overnight, nor was any one man responsible for the invention of metal detection.

THE PIONEER
If any one person could be regarded as the inventor of metal detectors, I will nominate English geologist and mining engineer R. W. Fox. It was Fox who first discovered that electricity will flow through metallic ores as well as solid metal objects. Thus, circa 1830 he devised a simple metal locator which consisted of nothing more than a battery, several metal rods and a suitable length of wire. His first method of detection was as follows: one metal rod would be driven into the earth where the suspected vein of ore was located; it was connected to one terminal of the battery. The other battery terminal was connected to a floating wire. Other metal rods were driven into the ground at several different points and successively touched with the floating wire. Where a spark occurred, it was an indication that metal was present. Circa 1870, this device was modified to two rods insulated from each other in a common probe and connected via battery to a bell and plunged into the earth. When contact was made by metallic ore, nugget or metal pipe, the bell rang, thus indicating the presence of a conductive object.

THE INDUCTION BALANCE

In 1879, Professor D.E. Hughes demonstrated to the Royal Society in London his Induction Balance (I.B.). Its purpose was to study the molecular structure of metals and alloys. However, Hughes and his instrument maker, William Groves, soon recognized the potential of the I.B. as a metal locator, and several were supplied to various London Hospitals for locating metal objects in human bodies. The Royal Mint used the Induction Balance for assaying metals and detecting forgeries.

The well- known American inventor George Hopkins modified the I.B. for locating metallic ores, treasure chests and the like. In fact, the Induction Balance forms the basis of most metal detectors we use today.

FURTHER DEVELOPMENTS

On June 21, 1902, the London Electric Ore Finding Company filed an application at the British Patent Office for an entirely new type of metal detector. This was a very advanced instrument for its time, having a range of one hundred yards. It operated as follows: a bank of batteries supplied a high-voltage, heavy-duty current to a spark generator; its output was chopped by a motorized contact breaker to achieve a signal at audio frequency, which in turn was fed to two transmitter probes driven into the earth. At a suitable distance away, two similar probes were connected to receiving apparatus, and equipotential lines of conducting material (ores or solid metal objects) could be plotted.

This company also developed an underwater spear-type detector which was used in locating gold bars in the wreck of the LAURENTIC, which was torpedoed during World War 1. This was a discriminating-type detector which could distinguish between gold and other metals. Unfortunately, the patent specifications are very brief and no illustrations are enclosed, hence we lack full information of how this detector worked.

Electric Metal Locating Company of Chicago took a different approach to metal detection, and based their instrument on the Wheatstone Bridge principle with two ground probes as sensors. A similar principle was employed by another American inventor Fred H. Brown who, in one of his patents, actually specifies his detector as being suitable for locating buried treasure.

THE WIRELESS AGE

With the very rapid development of wireless techniques during World War I, it was only natural that this technique would be adapted to metal locators and prospecting equipment. One of the first pioneers to exploit this technology for locating buried treasure was Englishman George Williams, who was the wireless operator aboard the salvage ship RACER during the recovery of gold from the wreck of the LAUREN TIC. Being fully conversant with wireless techniques, and seeing the somewhat primitive treasure locators available then, he decided he could improve the existing technology by designing a Radio-Locator (as metal detectors were known then).

In the book, “DIG FOR PIRATE TREASURE,” the author states that, “Williams had a metal detector of his own invention and used it to good advantage in Panama.” This surely must be the greatest understatement ever made relating to buried treasure. Further on, the author goes on to say that Williams “unearthed some wonderful stuff, including gold pots, candlesticks, silver bells and many historical things. A solid gold ball seven inches in diameter with a cross on top and gold leaves underneath.”

On January 7, 1928, The London Times newspaper reported that Williams found “a solid gold altar two feet high,” while C. B. Driscoll in DOUBLOONS expands the finds list even further. He also describes the Williams’ detector as a Transmit-Receive instrument operating at radio frequency. Williams, with his locator, arrived in Panama in July 1925, hence he certainly was one of the pioneers of T-R technique (see author’s note).

At approximately the same period of time, Radiore Company of Los Angeles developed a large-scale metal prospecting apparatus operating at fifty kilohertz.

Circa 1926, SCIENCE AND INVENTION magazine published construction articles under the title, “The Radio Gold Explorer.” So we see that even amateur gold hunters were catered to. By the mid-1930’s, there was an abundance of gold and treasure locators, the most notables being: the Alpha by George Maher, Terrasearch from Engineering Research Corporation, Radioscope by Goldak, Inc.; and, of course, Metalloscope from Gerhard Fisher. The Metalloscope was undoubtedly the most popular treasure finder of all time having survived in continuous production right up to the solid-state era, hence the M-scopes of the current Fisher line of detectors.

AUTHOR’S NOTE: In this article, I have attempted to give historical development of metal detection during the first 100 years of the use of electricity and electronics for this purpose, although other devices, mechanical (Dip Needle/Miners Compass) or physical (Pendulums/Divining Rods) were in use for several hundred years prior. As no reference books are available on this subject, I have relied on patents and articles published elsewhere to gain the necessary information. However; there are large gaps in my knowledge. For instance, the technical information and illustrations of the George Williams’ detector. I would be very pleased to hear from anybody who can supply further information. Please write to me direct at: 34 Nelson Gardens, London E2 7M, England.

 
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This story first appeared in Gold & Treasure Hunter Magazine Nov/Dec, 1991 on Page 29. This issue is still available! Click here.

By Dave McCracken

It is nearly always important for a prospector to target his or her sampling efforts to reach the bottom of hard-packed streambeds.

Dave Mack

 

Successful mining in streambeds is generally accomplished in two steps: (1) prospecting and (2) production. This is true on any scale of operation. First, you need to find a gold deposit, usually a pay-streak. Once the deposit is located, then you can concentrate on a production program to recover the gold from the deposit.

Prospecting generally consists of digging or dredging sample-holes in different locations, then comparing the results of the different samples. Through trial and error, the positive signs are then followed into high-grade gold deposits.

In a waterway, the first effort should be to locate the common path along which most of the gold typically travels. Sampling is then performed along that path to find the pay-streaks. This system is thoroughly outlined in Gold Mining in the 21st Century, and Part 1 of Advanced Dredging Techniques.

Dave’s Books & Videos

The following video clip also demonstrates this very important principle:

When you are sampling, you should nearly always be looking for hard-packed streambed material. “Hard-pack” is created at the bottom of waterways during major flood-storms.

Generally, a winter storm, even a large winter storm, will not create enough turbulence and force within a river, creek or stream to redeposit the compacted streambeds that are already in place along the bottom.

Flood-storms of the magnitude to redeposit streambeds do not occur very often.

For example, on the Klamath River in northern California, where my own team dredging operations take place during the summer months, we believe the last time that a substantial amount of hard-packed streambed was formed was during the 1997 flood. An even larger storm took place in 1964. In many places, a 1964 flood-layer was laid down on top of a much older, harder-packed, virgin streambed — one formed perhaps thousands of years ago.

To give you an idea of the magnitude of storm that it takes to create hard-packed stream-beds, take a look at the following video sequence I captured just down river from Happy Camp during the flood of 1997:

So, it takes a major flood storm to move and lay down a hard-packed streambed. And, it takes a super-sized major flood storm to create enough force and turbulence in a river to break up ancient streambeds and redeposit them as newer hard-packed streambeds along the course of the waterway. This happens only very rarely.

The reason that hard-pack is important to a prospector is because gold nearly always concentrates at the bottom of hard-packed, flood layers. Therefore, it is nearly always important for a prospector to target his or her sampling efforts to reach the bottom of hard-packed streambeds.

The following video sequence shows exactly what hard-pack looks like. I captured this video during a Group Mining Project in a location where we were recovering a rich gold deposit from the bottom of an ancient streambed layer resting on bedrock:

Gold is about six times heavier, by volume, than the average weight of the sand, silt, and rocks that make up an average streambed. Because of this disparity in weight, when streambed material is being washed downriver during a major flood-storm, most of the gold will quickly work its way down to the bottom of the streambed material that is being carried along by the raging flood waters.

In the following video segment, watch how fast the gold penetrates average streambed material once it is placed into suspension. The second video segment provides a visual demonstration of this very important point:

Because the gold is so much heavier, it will work its way down along the river-channel more slowly than the other streambed materials. During major flood-storms, most of the gold moving in a waterway will be washed down across the bedrock, or across the surface of hard-packed streambed that is not being moved by the storm. At some point during the storm, gold becomes trapped out of the turbulent flow by dropping into irregularities, cracks and holes that are present along the surface over which it is traveling.

Placer Geology

As shown in the following video segment, other heavy materials, like lead and old iron objects, also travel and deposit in the same places as gold. These other materials can sometimes lead you right into a rich gold deposit:

Because of its enormous weight, gold also deposits much earlier during the course of the storm than the streambed material which eventually seats itself on top of a pay-streak. As the storm begins to taper off, and the water-forces begin to slow down, particles of gold will start dropping out of the flow. Along the path where most of the gold is traveling in the waterway, traces will be deposited, with more substantial pay-streaks forming within the larger, low-velocity areas. These gold deposits are being laid down even as the (much-lighter) rocks and gravel are still being washed down river with the storm flows. Streambeds form later in the storm, when the water-turbulence tapers off enough to allow the rocks, gravel, sand and silt to drop out of the flow and form a seated bed along the bottom (over top of the gold).

Streambed material that lies in on top of a pay-streak will nearly always be hard-packed. The reason for this is that if there is enough force and turbulence to move substantial amounts of gold in the waterway, then there is also enough force to create a naturally-formed streambed on top of the gold as the same storm tapers off.

How do natural streambeds form? First, the storm needs to be powerful enough to rip up the streambed material, put it into suspension, and wash it down the waterway. This process is similar to gravel washing through a sluice box, only on a much larger scale. During the later course of the storm, as the water-force and turbulence starts slowing down, natural obstructions or traps along the river-bottom will allow certain key rocks to become lodged or seated. An example might be a flat rock that drops into a bedrock indentation, with the forward edge of the rock pointing slightly downward into the flow. The water-current then holds the rock to the bottom. With this rock in place, new locations are formed for other rocks to become lodged. Smaller rocks, sand, gravel, and silt will fill every gap and crevice in a manner similar to the mortar used to cement layers of brick. More rocks then fall into place. More filler then packs the spaces created between the rocks, and the bed forms.

Hard-packed streambeds form mostly with the flat rocks lying horizontally and slightly tipped downward against the direction of the current. The way in which streambeds form during major flood storms leaves the bed-material seated and compacted together, much like a mechanical structure. In dredging, we call this structure “hard-pack.” Most of the gold in present waterways is covered over by hard-packed streambed. So it is very important to know what it is. The following video segment shows you exactly what to look for:

For substantial amounts of gold to move within a waterway, it requires a major flood-storm with enough power to blast up some of the pre-existing hard-packed streambeds. This is because most of the existing gold in the waterway is trapped below existing hard-packed streambeds.

It is the abrasive action of the streambed material (more like a huge band-saw), as it is being washed down along the bedrock during major flood-storms, that causes bedrock channels to cut deeper into the earth over geologic time. When such a storm tapers off, new hard-packed streambeds will form over top of the gold deposits.

“Loose-packed” material consists of sand, silt, rocks and gravel which possess little or no natural structural cohesiveness. When you dredge a hole down through loose streambed material, it keeps sliding in on you. Digging through loose-pack can be like trying to dig down through a pile of sand or gravel. The material keeps slipping into the hole. This makes for a much more difficult sample hole if the material runs deep.

Sometimes, loose material is resting on top of a hard-packed streambed and must be moved out of the way first, before the hard-pack can be properly sampled.

When you dredge a test hole through hard-pack, the streambed will generally hold up the wall surrounding the hole. In fact, many of the old-time operations tunneled underneath hard-pack. This was/is called “drift mining.” Sometimes they even tunneled directly under active rivers!

It is also important to be able to identify tailings. Tailings are easy to identify, as long as you understand how streambeds are mined. Tailings do not look either like hard-pack or loose streambed material.

When hard-packed streambed is being mined, the cobbles and boulders (i.e., rocks that are too large to pass through the recovery system) are tossed back onto a pile behind the production area. As the production area moves forward, piles of boulders and cobbles are left behind in place of the original hard-packed streambed. Sometimes, sand, silt and gravel that is processed through the recovery system is dropped on top of the cobbles. Later, winter storms also wash sand, silt and gravel across the top of the cobbles. The sand, silt and light gravel then filters down and fills in most of the space between the cobbles. Therefore, tailings usually end up as loose stacks of cobbles with sand, silt or light gravel filling the spaces.

A large flood-storm may wash the tailing-cobbles away at a later time and redeposit them into a newly-formed hard-packed streambed. Or, as in the case of the 1964 flood in northern California, rather than wash away all of the cobbles, many of the piles were leveled off by the storm, and a new layer of hard-packed streambed was deposited directly on top of the loose cobbles. When we dredge sample holes in those locations, we usually find a hard-packed streambed on top of the tailings (loose cobbles). If gold traveled in that part of the waterway, we find it concentrated at the bottom of the hard-pack, sitting on top of the tailings. Underneath, we find loose cobbles with sand and silt between them. These usually go all the way to bedrock. We find very little gold on bedrock, because it has not yet been directly exposed to a major flood storm since being mined.

  

Some waterways will have several different natural streambed layers, each with its own concentration of gold resting on top of the layer or bedrock below. Different streambed layers usually exhibit a different color and compactness. The “contact-zone” between the layers is generally pretty easy to spot. Within the contact zones between layers, and on top of bedrock, is where you will find most of the gold concentrations. Those areas, then, should be the target of your sample holes.

As shown in this following video segment, sometimes the highest-grade deposits will be found up on top of a layer of hard-pack in the streambed:

Seldom will you find rich pay-streak gold deposits associated with loose streambed material. However, it does occasionally happen. These occurrences are almost always the result of winter storms, and the resulting run-off, eroding away a hard-packed streambed along the bank — which washes the gold down into the waterway to rest with the loose material.

There are areas in Africa where streambeds consist entirely of loose gravels – sometimes which carry substantial amounts of gold and/or gemstones. But this is an exception to the rule.

Effective sampling is the key to a successful mining operation. And, when you are sampling, you should be looking for hard-packed streambed layers. Watch for the gold concentrations along the bottom of these layers, because that is where you will usually find them.

 

BY JOSEPH F. GROUT

Preparing Yourself Properly for a Gold Prospecting Adventure

 

Each summer, thousands of prospectors head for the high country in search of gold. However, not all of these prospectors are from the mountainous regions which they will be entering. In fact, I’d be willing to bet that the vast majority of prospectors are from flatland areas of the Midwest and East. Therefore, it is an easy observation that you prospectors should take some extra precautions and attempt to prepare yourselves for what you will encounter in the high country.

Obviously, one of the best things you can do to help ready yourself for a high country expedition is to get in shape. Luckily, there are many exercises that will help you get into top physical condition, but you must be willing to discipline yourself and stick with your exercise program.

Basically, there are four elements to a S.A.F.E. prospector fitness program.

These elements are Strength, Ability, Flexibility and Endurance. While everyone is born with ability, the other three elements are the things that must be worked on.

If you are serious about starting an exercise program, it is important that you stretch for several minutes prior to each workout. This stretching will improve your flexibility and help you become more limber.

Maybe the most important thing that a would-be high mountain prospector can do is build his or her strength. After all, you must be physically strong if you are going to carry a backpack into a remote wilderness setting!

If you are serious1y interested in building strength, it is important to work with a given weight until it is easy for you to perform several repetitions without any problems. As soon as your starting weight becomes easy, add more weight! However, if you are mainly concerned with muscular endurance, which most prospectors are, then you should probably stick with lighter weights, adding more repetitions to a set.

Some weightlifting activities I utilize when preparing for a high mountain prospecting trip are the bench press and leg press. The leg press is probably the most important of the two, as it helps your legs build strength, which is vital, due to the fact that your legs will be your transportation.

After you finish a workout, you should cool down and do a few more minutes of stretching, as this will help prevent your muscles from tightening up.

Building endurance is another important part of any prospector’s life. Every spring, after a lethargic winter, I attempt to build my endurance by taking long walks. Walking is an enjoyable endeavor that you can do by yourself or with others. There is no need to walk at a fast pace; and as you walk, relax and take in any sights and sounds along your travel route.

Normally, if you are a prospector, you are also an outdoors person. This means that you may have fish and wild game in your freezer. Both fish and wild game are excellent foods. Therefore, as long as we cook these foods with low fat and cholesterol in mind, they will fit in nicely with our exercise program.

Now, let us suppose we are healthy and fit as a fiddle. The next step before traveling to a destination is deciding what items we need to take with us. This is where things can get tricky, because most people attempt to take far too much. As you are deciding what to take, keep in mind that everything you take will be in your backpack, which is of course carried on your back. Whenever I go high mountain prospecting, I normally hike as high as timberline and sometimes even higher. Therefore, I like to keep my backpack as light as possible while still carrying the essentials.

Some of the items I carry are: a light-weight sleeping bag (capable of keeping me warm in very cold temperatures), toiletries, a first-aid kit, a Eureka Mountain Pass tent, a pair of cotton gloves, a gold pan and classifier, a suction bottle, vials for gold, rope, an extra set of clothes (two sets of socks), fire starters (wax strips), weatherproof matches, a small camp shovel, topographic maps of the region I am in, some military MRE’s (food), fishing tackle (flies, leaders and line), a telescopic fly rod, a mess kit, a poncho, and a firearm of some kind. I also tie a military coat and stocking cap onto the outside of my pack, as the temperature at high altitudes can get surprisingly cold. On my military web belt I wear a hunting knife and a canteen, with a canteen cup.

While I realize that these items are the bare essentials, they will have to suffice; because more weight is impractical. Remember, you are going to do a lot of climbing, so keep it enjoyable.

As soon as your destination is known, you may want to consider staying at a motel in a high mountain town for a couple of days, before entering the forest. Staying a few days at a motel or local campground will help you become a little bit more accustomed to the altitude you have entered. If you attempt to head right into the mountains without becoming acclimated to high altitudes, you may experience altitude sickness. Altitude sickness is caused by the thin air your body is unfamiliar with. I have learned, through a very scary personal experience, that altitude sickness is something to be taken very seriously. Remember, you cannot beat the mountains; and if you think you can, you will find yourself getting beat! Respect the mountains and your trip will be much more enjoyable.

Entering the wilderness is a great experience that is almost indescribable. It is easy to find yourself imagining that you are the only person around for thousands of miles. For instance, when I go to the mountains, not only do I prospect, but I also take plenty of time to enjoy the solitude and great trout fishing that the high mountain streams and lakes offer. When in the deep forest, I can think my own thoughts and do what I like. It is a feeling of independence, where only the most hearty and rugged individuals can make it!

Enjoying the mountains also requires that you have a basic understanding of weather patterns. You don’t want to become caught in a serious storm. Keep in mind that lightning is very common in the mountains, and you should try and avoid bad weather.

Upon reaching a suitable location for a base camp, the real adventure begins! I make a good camp and then, feeling1ike a child on Christmas morning, I grab my gold prospecting gear and begin searching for a likely place to try my hand at panning. Normally, I enjoy panning along small creeks. There is something mystical about panning along a creek!

The key to finding high-grade gold is in knowing how to prospect, and in having the right attitude about it. If you don’t have much experience in it, I would advise that you attend some training and gain some experience under the watchful eye of seasoned professionals before striking out on your own. This will save you lots of time in trying to muddle through the learning curve on your own.

My first day of panning is usua1ly short-lived, because there are many camp chores that need to be done. Gathering wood for a small fire is critical. A small fire provides warmth and a means of cooking the trout that I catch.

Fishing for trout in high mountain lakes and streams is something that all prospectors will enjoy. The trout, normally not very big, are scrappy fighters and are just about always ready to hit a properly-presented fly. Some of the flies I regularly use are the western bee, black gnat and royal coachman. However, the fish at this altitude are not picky and will hit almost anything.

The mountains have been a home away from home for my family for 100 years. They have seen my grandfather, my dad, and myself enjoy all that they have to offer, providing us with an understanding of what it takes to be responsible and self-reliant.

While I have not become rich yet by prospecting for gold in the mountains, I have found enough gold to pay for my entire prospecting trip. The experience of a high mountain prospecting trip, however, is worth more than any monetary return to me. Especially when I find a deposit of gold nuggets!

Still, I have not given up hope of striking something rich. That possibility exists; and, I suppose, is the thing that makes prospecting in the high country one of the best adventures available to man – or women!

Becoming a high mountain prospector may not be for everyone, because it requires an able-bodied, physically fit person who has a strong mind and a desire for adventure. If you believe that you have these characteristics, what are you waiting for? After all, there is no time like the present to experience the adventure of a lifetime!

 

By Troy (Hank) Donovan

 

 

Book graphicTo become a successful gold prospector, research must top your list of things to do. Research will provide you with a never-ending source of future prospects. Experiencing the joy of being in the field, while enjoying these exciting and rewarding activities, should be a major priority for everyone. Furthermore, repeated trips going into the field, being successful, attaining your goals, and coming home with golden treasures is what puts the icing on the cake. The main ingredient to help ensure success in gold prospecting is taking the time to do truly adequate research and planning.

Research is the “all-important” first step that needs to be accomplished. Learn everything you can about the activity. Read appropriate books and magazines, and speak to other people with the same interests. The Internet provides many vital connections. E-mail other enthusiasts. This will prove to be very useful in the future, and can help you now! There are many web sites worth examining. Thousands of Internet sites are just bursting with useful, valuable information which can help you.

Another very important component of research is putting lots of time in the field. The time you spend in the field provides you “hands-on” familiarity with your equipment and the areas where you are prospecting.

These hints are just the tip of the ice-berg of research. Become familiar with your equipment. Start to develop an intimate “feel” for what you are doing, and what you are looking for. Make some good connections through various prospecting clubs and associations and Internet sites. Then, it is time to begin the arduous, but rewarding, task of developing some of your own “hot spots.”

“Hot Spots” are places waiting to be discovered—by you! These places are located all over the west. Often they are referred as “virgin sites,” No one with a metal detector or a gold pan has ever been there (except for you!) “Hot Spots” can also be forgotten sites; places that very few people know about, today. These may have been explored by earlier generations of prospectors; but with today’s technology, they are worth checking out again!

To discover these sites, begin searching at your local library. Doing your research in the library can be a very mundane process. Spending hour upon hour sorting through maps and old newspapers, while not being entirely certain what you are looking for, can be very frustrating. More importantly, it can be time-wasting. To avoid this waste, go to the library with purpose, and be focused on your task. Are you hunting for old placer mines? Abandoned lode mines or their tailings dumps? Old hydraulic mining areas? Decide what you are searching for. Then narrow your search-effort, allowing yourself to use your time more efficiently.

Historical newspapers from the area of your interest can be a resource tool. I bounce back and forth, scanning microfilm, alternately searching through old books and maps. By acting like a metal detector with discrimination, I scan for key words, and ignore irrelevant information.

Maps, as you can imagine, may be a gold mine! To find these old maps, ask the librarian if they have a room dedicated to your State and/or County. Most libraries have rooms, or at least special sections, that are packed with local history! Many times, these areas are pretty disorganized. But such disorganization might actually be to your advantage. Maps and books which are buried in old boxes might be exactly what you are looking for! For a nominal price, some mail-order catalogs will also provide you with maps that can be helpful.

Sometimes, modern maps can produce clues from yesteryear, while providing you with leads from which to do further research. Often, browsing through a map, you will notice gulches, creeks, mountains, and roads that have interesting names. For example, on one of my gold prospecting research sessions, I came across a small creek called “Sluice-Box Creek.” Doing further research, I discovered there was a large population of Chinese miners working the area during the 1890’s. Little prospecting had been done since that time! Here is a prospect that might be worth checking out this next season!

Old maps often actually show the exact location of old mines, sometimes even including the names. Then searching for the names can sometimes give you valuable information about the mines. Modern GPS electronics can then help you locate those old mines in the field!

There is nothing really difficult about all this. It takes time; and it all requires a proper state of mind. The best things in life don’t always come easy. So you have to allow yourself some time.

It is very important to keep all of your information and leads well-organized. I suggest that any photocopies that you make from books and micro film should have a notation of the author, title, and date of the publication from which it came. This might be important in the future. When you discover at some later time that you need more information from the source, you will more-easily know where to find it again! Many times while doing research, you will find both useful and useless information. Keep all information you find! I cannot count how many times I have gone through my papers, finding a new piece of information that I had not noticed before, or information that was not important previously, but is now!

It is also a good idea to keep a journal. This can be a very useful tool while out in the field. Many times, you may come across something interesting while out prospecting. Mark the location using your GPS. You might want to do some related research at a later date. By pinpointing interesting prospects on your map, and writing some useful notes, you will be prepared to go the library and possibly locate some historical information on the particular site.

Remember, research is your best possible tool to help develop potential new prospects. The more time spent on research, the more you will be rewarded with productive sites to discover new “golden treasure.”

 

By Sam Radding

How to Determine what “Good Gold” Means to You

 

Damp soilThe meaning of “Good Gold” is a matter of perspective and experience. This phrase is generally used in terms of quantity and ease of extraction. A couple of old-timers, sitting around the fire talking gold, will often have enough shared-experiences to know what the other means by “good.”

“This soil is very damp.”

The captivating nature of gold brings out different emotional responses from each of us.

The problem lies in the fact that just about every novice miner starts with little or no knowledge of the realities in the activity of gold prospecting. Our story may serve to shed some light on what to expect from your own first few mining trips.

Jean and I live in San Diego. To start with, our part of the country is very dry. So, a lot of the gold hunting is accomplished using a dry-washer. There are a few placer areas within an hour’s drive of our house, but they have very limited access and the gold tends to be pretty sparse. We tried some gold panning and found a few specks of gold; but from what we could determine from the local prospector’s club and friends, the Pot Holes would be a better-than-average place to start. This area is about a three-hour drive from San Diego, and is near Yuma, Arizona, but still in California.

Dry-washerBuilding a workable dry-washer would be a snap. I have always been good at figuring out how machines work and how they should be constructed. Ten minutes with a friends’ bellows dry-washer was enough to get me started on our own machine. A few days later, we were packed and driving to the desert with our newly-built dry-washer and an old 3-horsepower Briggs and Stratton engine. I just had to test my new creation. When it comes to gold, to me, now is always better than later.

Our maps were good, so we had no trouble finding the bridge across the American Canal along with the road to the open recreational mining area just southwest of the old 3 C’s mine. The road in had a few rough spots, but nothing that our little Vega station wagon (with three-inch ground clearance) could not make. By the way, this location still remains open to anyone; and to this day, it is still productive.

The big problem was where to start. Book gold is a lot different than real gold. The books we read were small and the maps and locations where gold would be trapped seemed fairly straight forward. The Pot Holes was huge; and of course, we wanted to work in the best spots. We wanted to find some “Good Gold!” I had read several articles about the importance of prospecting and sampling before you decide to invest the bulk of your resources to any particular area.

Jean and I do argue on occasion; and as it turned out, picking-out our first dry-washing spot was a perfect time to disagree (Thirteen years later, so we can minimize disagreements, we now have two of almost all the equipment we use.). After about fifteen minutes, we jointly settled on a small wash. There were a few tree roots and some exposed bedrock to work. This wash was about a hundred yards from where we parked the car. After packing our gear to the site, we set the engine and dry-washer in place; with the engine upwind to keep it free from the dust generated by our dry-washer. Then, with the dry-washer delivering about 90 beats per minute (possibly a little fast for the conditions we were working), we proceeded to dig and feed gravel to the dry-washer for about a half-hour. We had brought along some water for the purpose, so we practically ran back to the Vega to pan our concentrates. Much to our surprise, we had almost no gold. We just had some small specks.

Our next spot was just down from where our first little wash emptied into a slightly larger dry-wash. The opposite bank looked good to me. There was some exposed bedrock, and the overburden was only about a foot deep. The digging was very easy; and after an hour, we decided once again to check our progress. I was impressed this time. There were lots of little flakes. Jean was not so favorably-disposed. It still looked like specks to her; and after a short time, it began to look that way to me, too. Another move seemed to be in order. We spent the next two and a half days moving from place to place, from specks of gold, to specks of gold.

Jean was getting a little frazzled, and I was getting more and more frustrated. I wanted to go back to the place that impressed me on the first day. The bank on the small wash gave up about 1 pennyweight (about l/20th of an ounce) of gold in an hour, even if they were only small specks. To us, it did not look like very much gold and I didn’t know if it was good or bad; but that spot seemed far better than the other places we had dry-washed during the past few days. I really wanted to go back.

Jean went back to camp to make lunch and I picked up the dry-washer, engine and the pick and shovel and started off to my spot. After about ten steps, I heard a rumble. My first thought was that it couldn’t be thunder, not here. A quick glance over to the west set me straight. Over my head, it was sunny and blue. A few miles away, it was dark, very dark. Even I knew that it was impossible to dry-wash in wet material.

The thunderstorm might move the other direction. But at worst, I would have a little time to work. I hobbled to my spot, carrying over 75 pounds of gear and equipment, and quickly set up the dry-washer and engine. If it was going to rain, then I was going to shovel as much material through the dry-washer as it would take. I worked hard as the storm crept closer. The first big drops of rain arrived about an hour later. Ten minutes after that, our dry-washing was finished for this trip. I had kept the riffle tray dry as I had been told. Dust and moisture in the riffle tray cloth create cement, and that combination will not pass air. No air means no gold; which in turn, means stretching a new cloth for the dry-washer.

Everything else was wet. We panned-out my concentrates, and our total gold for the trip filled a two-pennyweight vial and half of another. We had over 3 pennyweights, most which came in two hours of dry-washing at my spot. It still looked like specks, but there sure were a lot of them. Our problem was that we had no yardstick by which to judge “Good Gold.” Back home, we told some mining friends about our spot in some detail and about how we had done. We thought there might be some more gold there and we were going back in a couple of weeks, after things had dried out a bit. Our more-experienced friends were impressed when we showed them our gold from our very first prospecting trip.

If you have never dry-washed, you must remember that any moisture in the pay-dirt will make any dry-washer less efficient. An easy way to check for water-content is to squeeze a handful of your pay-dirt into a ball. Then open your hand. If the ball falls apart, the material is very dry. If the ball breaks into several smaller sections and tends to crumble, you are working with slightly-damp material. Most dry-washers will run this material, but the efficiency will be diminished somewhat. If the ball stays intact or breaks into two or three parts, the pay-dirt must be dried before running through the dry-washer. On a good day, most dry-washers will lose between 10% and 20% of the finer-sized gold which remains trapped in small dirt balls. They pass right through the machine!

When we got back to our spot three weeks later, the site had already been cleaned out. We did get a little more gold, but we later found out that a few of our more-experienced friends went in there before us and recovered about two ounces of gold during our absence. From that time forward, both Jean and I had a little better understanding of what the term “Good Gold” means!

To this day, I still have a hard time keeping my mouth shut when it comes to where we are working and what we are finding. Most gold prospectors that we meet find this an endearing, if not a foolish, trait to have. I am getting the idea that when it comes to gold, you have to be careful how you conduct your business affairs!

If you are just starting out, whether you are working on a river, stream or in the desert, or whether you are using a dry-washer, sluicing system or four-inch dredge, recovering a pennyweight of gold an hour is making “Good Gold.” Two-to-five pennyweights in a day’s work is fairly good for small equipment. I personally average a little over two pennyweights per day when I am sniping (finding gold with hand tools and a face mask) on my favorite rivers in the Mother Lode area.

Over the years, I have built over a hundred dry-washers, both the bellows and constant-air types. I have written books on the home-construction of small-scale mining equipment. Jean and I spend most of every summer looking for gold. More gold is always better than less gold; but to me, I feel I have done well if my final clean-up produces over two pennyweights in a day. This is my personal yardstick for how I am doing. The amount of gold we find is important, but we are also enjoying what we are doing.

Here is where you can buy a sample of natural gold.

 

 

BY DON PADGETT

During my fourteen years of mining throughout the United States, with a variety of gold mining equipment, I’ve seen and processed a lot of black sand. And since the mining equipment I’ve used has ranged in size from gold pans and suction dredges to Caterpillars and heavy equipment, its been possible to approach “fine placer gold recovery” and its liberation from black and blonde sands from virtually every level.

Learning in any form takes time and usually a lot of practice, which all too often includes making a few mistakes. So I might as well begin this article by admitting that I’ve certainly left my share of gold on the ground, even after all the hard work of getting it out of some of nature’s most elusive hiding places.

Liberating gold from black sand can be a very difficult process, especially when the gold is extremely fine. The finer the gold, the more difficult the recovery seems to be. And whether you’re an experienced miner or a novice, it is certainly a waste to walk away from your fine gold, leaving it half processed in a pile of black and blonde’ sands at your clean-up site along the river bank or in your campground. For example, let me relate a true story of one of my own recent experiences:

During a recent winter, after a fairly good dredging season, the cold water and my own curiosity caused me to wander around and check out some of the black sand piles (left behind by other miners) I had noticed earlier in the season. Knowing from my own experiences how miners tend to lose gold during clean-up, I took along my gold pan to test with; and sure enough, in the first pile of sand I found two nuggets (about 1/4 and ½-pennyweight) along with plenty of color. I immediately went back to camp and returned shortly with my shovel and some buckets which I used to transport the heavy black sands back to my campsite where I do my own clean-ups. I use an industrial-type spiral-wheel which is larger and faster than the typical gold wheel sold in most mining supply stores. Gold wheels will do a great job of fine gold recovery providing they are set up and used properly. And since every wheel and concentrate deposit is unique, your ability to tune your wheel and work your sands will be the critical factors affecting your fine gold recovery, not a particular brand name.

During the past few months, I’ve also been running the final clean-ups from a number of mining operations along the Klamath River in northern California. In most cases what were only five gallon buckets of “previously processed” black sands magically changed within a few hours into literally pennyweights and ounces of liberated fine gold. You can just imagine the surprise and excitement experienced by these dredge operators when they saw that the black sand byproduct they had so very often considered “nearly worthless” or “unrecoverable” was in fact valuable and could even pay a substantial portion of their operating expenses.

Most of what I’ve learned was to a large extent the result of associating with some of the best clean-up men in the gold mining fields of Alaska. They had been liberating gold for more than fifty years when I first met them, and many are probably still at it today. If there is a single and most important key to unlocking the mysteries of fine gold recovery, it is “the basics always work.” So if you’re in fine gold, and you’re not able to recover it, remember to return to the basics.

What follows is a simple step-by-step process of the basics of fine gold recovery:

Without Classification, Liberation is not Possible

Virtually every piece of modern mining equipment currently available in local mining and equipment shops has its own inherent system of material classification. To classify, in mining terminology, simply means to separate the material (rocks, gold, and sand) by size and/or weight (usually by size). It only makes sense to take this process even further in handling the clean up of your concentrates.

Classification is often accomplished by using screens of various sizes or meshes, and while many gold miners choose to buy these screens from their gold mining supply store, it is not unusual at all to see lint screens, window screens, and even kitchen sifters alongside a clean-up operation. Classification screens come in many sizes: 4, 8, 12, 20, 30, 50, 100, and even smaller. These numbers represent the number of openings per linear inch. For example, a 4-mesh screen has four holes per linear inch or 16 holes per square inch, and allows material to drop through which is smaller in size than about 1/4 inch smaller, actually, because the wire in the screen takes up some of the space.

With a little practice and experimentation you will find out which screen will work the best for you and your particular clean-up operation.

Beginning Your Clean-Up

Start your clean-up by removing your concentrates from your sluice box. Next, use your #4 screen to classify and remove this spectrum of material, checking closely for nuggets and large, flat flakes. Surprisingly, many miners fail to inspect closely because they are working a deposit that only seems to produce fine gold. Nuggets can be lost because they are simply thrown out in this important stage of the process. Usually this first step is done right at the river bank, making what you must carry back to your camp less cumbersome. Now screen your materials though your #8 screen. What’s left on top of this screen will be easy and quick to pan at the river. Take what falls through the screen back to your wheel for processing.

Using Your Wheel

It is very important to go through the above steps before attempting to use your wheel to process your concentrates. Remember, the wheel works on the principles of weight, angle (pitch), and water-flow. In the following steps, you’ll be first separating the blonde sands from the heavier black sands. This process is called the “first split.”

This separation should be done using your wheel’s fastest speed if you have a variable speed wheel. This split will take a little time, but remember that if you were panning this material it would probably take as much time or more, and may not be as effective for fine gold recovery. Many people purchase a wheel to reduce the amount of panning time in their clean-up operation, as well as recovering more gold.

At this stage, you’ll want to pull the black sands and gold from the blonde sands. It’s okay if a small portion of the blondes are drawn up along with the blacks in this first split.

We have found that skimming the lighter sands off the top of the material being processed in the wheel (not in the riffles) can be more effective than allowing the tailings to simply run out of the wheel with excess water.

The best demonstration of how to use a gold wheel that I have ever seen is in Dave McCracken’s video, “Modern Gold Mining Techniques.

When running this first split, the wheel will pack just like the riffles of a dredge. When this occurs, for better results, you can spoon material from the bottom of the wheel up onto the riffles. We also seem to get better results by spooning material onto the drier section of the wheel so that it passes into the flow of water as the wheel turns. Watch yourself very closely because this is the step where many of the larger flat flakes are lost simply by scooping the material out of the wheel too soon. Once this split is complete, you should find that you have cut your material in half or more.

Now you should have what we call salt and pepper sand and gold. If you have only black sands at this point, you have probably lost some of the finer gold already. Look closely; and if this is the case, stop, back up and rerun this split again. Remember, the wheel will only recover as well as the skill of the operator permits. So take your time and make sure you’re not losing your fines at each stage of the process.

Next, classify the remaining concentrates once more using a #12 screen. This time you’ll only have half as much material so it will go very fast. The material on top of the screen produces your bigger gold; and if you’re in good gold, you’ll be able to still see it lying all over the surface of the screen. Sometimes, I find it easier to dry and run a magnet through the sands. This approach will usually remove 50% to 80% of the magnetic black sands, leaving your gold and just a little material to pan or blow off. These gold particles and flakes should be bright and beautiful and can be put in your gold jar.

Now it’s time to tackle the material that dropped though the #12 screen by running it through the wheel. When using a variable speed wheel, this split should be processed at the slowest speed, and the pitch of the wheel should be set at a steeper angle. Use a moderate-to-slow water flow, adjusting the wheel to pull just a little black sand, and all the gold. Once you’ve run it through, simply adjust the wheel a bit steeper and rerun this gold-laden material once more, only this time just pull the gold.

This process will leave you with all your gold, and perhaps just a very small amount of fine black sand. I find that if you dry this final product, it is very easy to blow the remaining black sand of by sorting through it on a clean piece of paper and blowing gently. It is a nice way to end your day!

And finally, if you’re having any trouble in your clean-ups, remember to return to the basics by watching your classifications, checking what you’re about to discard on a regular basis, and by making sure that you’re not leaving your fine gold for someone else to recover simply by re-running your old sand piles. I hope these hints are helpful, and good luck with your future clean-ups.

 

 

By Dave McCracken

To succeed at gold dredging, you should be willing to take a rather athletic approach toward the work, especially during the sampling stages.

Dave Mack

Gold dredging consists mostly of physical activity. Heavy gear has to be carried around from place to place. Much of your time is spent wrestling with a suction hose, picking up and tossing cobbles as fast as you can, shoving against boulders, fighting to hold your position against the water’s current, packing 60-plus pounds of lead around your waste, swimming back and forth across the river, and pulling dredges around on ropes. There just never seems to be an end to the physical work! This is not bad. Unless you don’t like hard work.

If you have a distaste for hard, strenuous work, if you don’t enjoy it and are generally looking for ways to avoid it, you need to find some line of work other than gold dredging. To succeed at gold dredging, you should be willing to take a rather athletic approach toward work, especially during the sampling stages.

Some people are physically-inclined by nature, and they enjoy hard work. Other people are not so physically inclined, but they are willing to work hard and do whatever it takes to succeed. Such people can be very successful at gold dredging. But, no matter what your inclination, gold dredging requires hard work. There is no getting around it.

I have found, to be most effective, it is best to attack a gold-dredging operation with a rigid work schedule, just like any other job or business-activity. I personally prefer to “pour on the steam” for three straight days. Then, I take one day off from dredging to allow my body to recuperate. The work is physically exhausting on the body if you really pour out the energy. You need to find the appropriate rest-interval that works best for you. Otherwise, your body will get overworked and start breaking down. I use my day-off to perform gear maintenance and the many other miscellaneous chores that are needed to keep the operation running smoothly. I try to get some much-needed free time out of it, as well.

 

 

 

 

My approach is not the only way. I know successful gold dredgers who prefer to work fewer hours each day, or work at a less-intense level of physical activity; but they put in five or six straight days at a time. If we could add up the total units of energy expended on dredging, it would probably come out about the same, either way. It is just a matter of preference and what pace you are most comfortable with. The main point here is that no matter how you cut it, you’ve got to put in the dredging hours if you want to succeed at underwater mining.

When people ask me about gold dredging as a profession, I always answer as follows: “Given the knowledge of how to do it, and the willingness to apply the knowledge, gold dredging is an easy way to make a living, if you are willing to work hard at it.” And, this is the simple truth.

 

 

BY ANTHONY “LITTLE TONY” STEURY, SR.

 

As usual, I awoke to the sound of a mother osprey’s loving shrieks giving instructions to her two young ones who had not yet mastered the art of flight. The sun was just coming over the top of Sugarloaf Mountain, quickly cutting the chill from the night air.

I could tell by the thundering sound of the rapids below my camp that the mighty Klamath River was rising at an alarming rate. The flood gates at the dam were being slowly raised, and I knew my time was limited. I felt that I must get down to bedrock under the rapids in order to find the gold that I knew had been waiting there for a gold dredger with modern equipment since the earth was formed millions of years ago.

As I quickly prepared a hot breakfast to help brace myself for the cold water I would have to endure, I reflected on the past two weeks dredging with my 6-inch dredge slowly moving yards of material, throwing cobbles, and moving small boulders to bore my way down to bedrock and get deep enough to escape the white water force that kept blowing me out of the hole. I was now at a point where most of the turbulence went over the top of my head, and I no longer had to work on my stomach with my face next to the nozzle intake to see. When I first started this hole, I was using 85 pounds of lead around my waist. One slight turn of the head would mean getting my mask or regulator ripped from my face by the turbulent force of the rapids.

I was snapped out of my interlude by the smell of burning bacon and a beautiful eagle gliding gracefully up the river taking full advantage of the thermal river canyon updrafts. Had I known then what events waited for me at the bottom of the river this day, I would have stayed in camp and dreamed of all the gold I had found in the years past.

As I put on my wet suit, my dog “Treasure” was already in the truck patiently waiting to go to our dredging operation as she had done so many times before. I think she knew our time was running out, and swimming the river to work our claim would soon be impossible.

I finished suiting up and grabbed all my gear. Twenty minutes later we were at the dredge, gassing up and getting ready to dive.

I took a quick look at my water marker, and it showed that the water had progressed 18 inches higher since yesterday. Not a good sign in the life of a fast-water dredger. Just as I started my engine and was preparing to slide down the suction hose into my hole, an ominous black cloud came from nowhere and totally blocked out the sun. It gave me a strange feeling as I looked up the side of the mountain and saw the old growth trees bending to a heavy wind by its awesome power. The cold, fast water slammed into my body.

As usual, my gallery was waiting for me in the bottom of the hole. Two ugly eels, three big suckers and many small fingerlings.

Without the sun, and because of a heavy flow of algae, it made visibility less then ten inches. I grabbed the nozzle and started plowing my way deeper around the base of a large boulder that I knew was lying on bedrock. Every day I had tried to move it with an 8-foot pry bar without success. “Today,” I vowed it would move. I threw caution to the wind and felt if I moved enough overburden from around its base, the force of the water would drop it on down behind me to the bottom tier of the rapids.

After steadily working for an hour and a half, I took a quick look at my watch and saw I had ten minutes of gas left. I was just about to go up and refill when the sun came from behind the clouds, allowing me to see that I had finally reached bedrock. There was a one-inch crevice starting at the base of the boulder making it a natural riffle. I took my small pry bar from my belt and pried into the crevice. Yes, I was right! Out came the gold into my suction nozzle. I had found the paystreak; I had outsmarted Mother Nature once again.

Just as I turned to go up and refill the gas tank on my dredge, I heard the familiar grinding sound of falling rock. A breathtaking pain shot up my leg causing me to spin around and grab my calf. As I did so, my mask and regulator were torn from my face. Experienced reflex made me grab my air hose to quickly retrieve my air source which I shoved back into my mouth, blowing out the water so I could breath God’s clean fresh air again.

At this point, after diving rivers and lakes clear back to when I was a young boy, I still panicked, causing me to hyperventilate. My mind started spinning to warn me I was about to black out. From out of nowhere, a voice was telling me to slow down my breathing, lie still and think things out before I became another one of the river’s many victims.

As my mind cleared, I started to run my hand down my leg, since without my mask, I could see only a few inches in front of my face. As I did so, again came the full force of pain which I was now more prepared for. After a quick search, my hand told me my ankle and foot were pinned under the large boulder that I had released with my foolish dredging around its base. I lay back again waiting for the pain to subside. Fighting panic, which would only bring me death, I took off one of my gloves and started to feel around behind me knowing my 8-foot steel bar lay somewhere near-hopefully close within my reach. It was the only chance of freeing myself, and a slim one at that. After groping around as far as I could reach, I was about to give up when my fingers touched steel. I arched my back and got three fingers around the point. Grabbing it the best I could, with my leg killing me, I pulled it toward me far enough to get a better grip and have total control. Just as I got it under and behind the boulder, I heard the engine stop from above.

I knew that there were only fifty-two seconds of air left in my holding tank. I twisted my body allowing me to put my unpinned leg against the boulder while, with arms above my head, I grabbed the top of the bar with both hands. I knew there would be only enough air for one chance to free myself. My mind raced back through my past. I thought of all the sporting events I had won in my youth. All the brave men who had died for their country telling me of all the things they still wished they could do. My family who still needs me and all of life’s battles I had won.

I felt a surge of power entering my body along with that gut feeling one always gets just before a win. I sucked in the last remaining air in my tank, pushing with my leg and pulling down on the bar with the 180 pounds of power that my body had to give.

Instantly, I fe1t the boulder move and I wrenched my leg free. Without hesitation, I ripped open my lead weight buckle release and shot out of the hole and down the rapids at breakneck speed.

In times past, this trip would mean a one-mile walk back up the river along a very rugged river bank, plus a one-hour delay swimming back across the river, floating down to my dredge, and retrieving all the gear I was forced to drop.

This day as my body was bounced along the bottom and slammed into boulders, I felt only the breath of joy while thanking a power greater than myself for this gift of life that was once again given to a mortal such as I. In a matter of minutes, my high-speed float trip was over, after being hurled into a slow water eddy which allowed me to drag myself up on a pile of cobblestones left by the old-time 49’ers.

As I laid back, totally exhausted from the pain and nerve-wracking experience, thinking about the fantastic gold deposit I had located, I looked up into the sky just in time to see my friend the eagle drop a wing tip to catch another updraft. He was, as always, looking after me and all of those who respect and love the river, saying farewell until another day dawned fresh in the life of the fast-water dredger.

 

By Dave McCracken

Specialized metal detectors will detect gold well-enough that they will sound-off on nuggets, deposits of smaller pieces of gold or even very small individual flakes of gold.

Dave Mack

 

 

Chrissy with her gold and metal detectorThere are many different kinds and models of electronic metal/mineral detectors to be found on today’s market. This is a guideline to give you the basic knowledge to help you choose the proper detector for your prospecting needs, and to help you use your metal detector as an effective prospecting tool.

There is a lot of electronic prospecting and gold nugget hunting activity going on at the present time. Consequently, there are different tools being used, along with several different popular approaches in how to properly-tune a detector and how to achieve the best results while searching.

It is important to point out that no two gold-bearing areas are exactly alike. An approach which might work better in one area, might not work very well in a different area. So, the purpose of this article is not to tell you what I think “the best” approach is. It is to give you information about each of the different approaches, so that you can gain a larger bag of tools to use when confronted with different situations out in the field.

I should begin by mentioning that the type of electronic detector used to find gold and other precious metals is not a “Geiger counter.” A Geiger counter is an entirely different electronic tool which is used to detect radioactive elements.

The type of electronic device used to prospect for gold is called a metal/mineral detector (“metal detector,” for short). Metal detectors are quite simple to use (once you understand them), and can be helpful in assisting you to locate gold or silver deposits or specimens once you have gained some personal experience in using one properly. While they are rather simple to use, it does take some practice with a metal detector before you can use one proficiently in gold prospecting activities.

There are many different models of metal detectors being offered on today’s market, most which are more useful to the treasure hunter than the gold prospector (two entirely different fields of detecting activity and procedure). Those detectors of most use to gold and silver prospectors generally fall under two separate categories: Beat Frequency Oscillator (“BFO”), and Very Low Frequency (“VLF”).

BEAT FREQUENCY OSCILLATOR

First we will take up the BFO, which is the simpler of the two—but is less-often found these days, due to the substantial electronic advancements of VLF detectors.

The BFO detector usually has two main settings, which are “metal” and “mineral.” As far as electronic detectors are concerned, the difference between the two is that “metals” are targets which are conductive of electricity–such as copper, gold, silver or iron. And, “minerals” are targets, or target areas, consisting of magnetic non-conductive materials such as magnetic black sands (Fe304). These are also known to prospectors as “black sand concentrates.” Electronic prospectors generally refer to them as “heavy ground mineralization.”

An iron object which has been in the earth for an extended period of time, and having thoroughly oxidized, will usually read-out on a metal detector as a mineral instead of a metal object–which it no longer is.

So the two basic settings on a BFO detector are “metal,” electrically conductive targets (gold and silver), and “mineral,” non-conductive magnetic particles (magnetic black sands).

The various models of detectors have different ways of sounding-out on reading targets. Some detectors have a light which turns on and off. Some have a meter with a needle on a dial–which will also give you an idea of the intensity of the signal given-off by various targets. Other detectors have a tone which changes in volume or pitch when passed over a reading target. Some newer-model detectors have an LED display which spells-out the different types of targets being encountered. Some detectors have a combination of these features.

Generally, the best type of metal detector for prospecting purposes is the type which includes an audio tone in which the audio pitch changes when the search coil is passed over a reading target, and which also allows a set of headphones to be connected. The advantage to using headphones while prospecting is that you can shut out the background noises from the surrounding environment and concentrate more intently on even the smallest audio changes which can and do occur while searching.

On most tone-changing BFO detectors, the tone will not only raise in pitch when the search coil is passed over a target for which it is set to sound, but it will also lower in pitch when the search coil is passed over a target of the opposite setting. For example, if a BFO detector is on the metal setting and is passed over a large gold nugget, the detector’s audio tone should rise in pitch. If the detector on the same metal setting is passed over top of a high concentration of magnetic black sand, the audio tone should lower in pitch. The same thing holds true in the opposite for the BFO detector which is adjusted to the mineral setting.

One other interesting thing to know about BFO detectors is they generally sound-out on the most dominant element, either “metal” or “mineral,” whichever is most present in the ground which the detector is being passed over. For example, if you are passing the search coil over ground which contains gold (this would read as a metal), yet there is a large amount of magnetic black sand in the same ground, it is likely that the BFO detector will read-out on the black sand as a mineral while ignoring the gold. Equal reading-amounts of both metal and mineral elements in a section of ground, in any quantity, will prevent the BFO detector from sounding-out on either element.

Because BFO detectors read-out so well on highly-mineralized ground, the presence of highly-mineralized ground tends to block-out reading traces of gold which lie in or under. This is known as “interference” in the electronic detecting field. Magnetite (magnetic black sands) has such a strong affect on metal detectors, that a concentration of only one percent magnetite in the ground may create a signal-imbalance which is hundreds of times stronger than the signal which might be given off by a small gold nugget.

So, a mineral reading on a BFO detector does not mean there is no gold present, only that there is heavily mineralized ground—which may be blocking-out gold readings.

One of the problems in electronic prospecting is that gold targets are often associated with highly-mineralized ground. Therefore, as a tool, the BFO has its advantages and limitations. In some prospecting situations, it can be very helpful to have a device which is good at pinpointing areas of concentrated heavy mineralization. The BFO does this exceptionally well.

This is further-discussed in my other article on this subject: Prospecting for Gold with a Metal Detector.

Some places where nuggets and larger flakes of gold become trapped do not allow heavy concentrations of black sand. One example of this would be a location (rapids) where the water runs fast over top of exposed bedrock during major flood storms. Such areas can be well out of the active waterway and directly accessible to metal detecting. BFO detectors can be very effective at helping to locate gold targets in places where heavy mineralization is absent.

GOLD TARGETS

Unfortunately, as a metal, gold is generally not picked-up very well by metal detectors. This is a comparative statement. Gold does not sound-off on a metal detector nearly as well as an iron object of the same size and shape. However, specialized metal detectors will detect gold well-enough that they will sound-off on nuggets, deposits of smaller pieces of gold or even very small individual flakes of gold.

No metal detectors are able to detect particles of gold dust at the time of this writing. This is probably a good thing, however; because there is so much fine gold spread throughout gold country that it would probably create additional interference problems on a sensitive gold detector.

Therefore, in electronic prospecting for gold, we are looking for flakes, nuggets and accumulations of gold. These are targets which will add up more quickly to something of good value.

It is important to understand that different makes and models of metal detectors are not equal in their ability to detect gold objects. Some detectors will just barely sound-out on gold objects. Others will not sound-out at all.

I highly recommend that any person who is buying a metal detector for gold prospecting purposes should bring along some samples of natural gold to test the various detectors before deciding which one to buy.

Small samples of natural gold and small nuggets are readily available by doing a search on the Internet or contacting a prospecting shop. This is to be sure that the metal detector you do buy will sing-out well when it is passed over natural gold objects, even very small gold targets. If a specific detector will not sound-out on gold held in the air, it will most-likely never detect gold targets located in the ground.

When testing-out the various detectors, it is better to use natural gold samples—like nuggets, flakes or a sample bottle filled with smaller-sized gold,. Some detectors will, and some will not, sound-off on small bottles that are filled with fine gold. Using natural gold targets is better than using a gold ring or some other type of jewelry. Jewelry is nearly always made of gold which has been alloyed with other metals (like copper)—which may read-out on a metal detector better than natural gold objects. Therefore, gold jewelry might give you a wrong idea about how well a metal detector will sound-out on natural gold targets.

The best detectors for finding gold are not necessarily the most expensive. Varying costs in detectors are sometimes in proportion to the amount of additional electronic circuitry that is built into the detector for extra features. These sometimes have little or nothing to do with the detector’s capability of locating gold targets.

Gold targets give a solid, mellow sound on a metal detector, similar to lead or brass. Pieces of steel wire and bigger nails usually give a stronger beep—or often a double beep.

The capability of a metal detector to sound-off on a natural gold target will partly depend upon what other metals the gold is alloyed with. Silver and copper make natural gold targets sound-out stronger. Nickel, mercury and platinum alloys make natural gold targets more difficult to find.

Metal detectors read-out on gold better as the pieces become larger. As an example, an average gold detector might sound-out very well when its search coil is passed over an eighth-ounce nugget from several inches away, yet not sound-out at all when passed over three times as much fine gold accumulated in a glass jar at the same depth or distance from the search coil.

Actually, it is not just the size of the target which counts. The object’s shape also makes a difference, and also the direction which a target is facing. A larger, more solid surface-area of gold will sound-out stronger. For example, a flake-shaped nugget is likely to sound-out better on a metal detector than a round nugget of the same weight, as long as the flat-surface area of the flake is facing in the direction of the metal detector’s search coil. Also, coarse and irregular-shaped nuggets, as commonly found in dry placer areas, residual and eluvial deposits, do not generally sound-out as well as nuggets which have been worked-over and pounded by flood storms in a streambed (because these are more dense and solid).

How tightly a gold deposit is concentrated also makes a difference in how well it will cause a metal detector to sound-out. Whereas a quarter-ounce of flake-gold inside of a jar might sound-out well on a particular detector, perhaps two ounces of the same flake-gold spread-out over a slightly larger area might not read-out at all with the same detector when the targets are at the same depth beneath the surface. This is one factor which is important for the gold prospector to realize: Any metal detector wills read-out on tighter concentrations of gold better than larger amounts of gold which are more widely dispersed. Metal detectors will also read-out on nuggets (larger solid pieces of gold) best of all.

DEPTH CAPABILITIES

How deep into the ground that a specific metal detector will sound-out on an object depends upon various conditions. Surprising to many, how much a detector costs may not have much to do with its depth-sounding capability. In fact, some of the less-expensive models are able to probe deeper, and pick up on gold better, than some of the more expensive detectors. The Federal Communication Commission has put a maximum limit on the signal-strength which can be used in metal detectors. So the idea that a more expensive model puts out a stronger signal to probe deeper is simply not correct.

The type of object has much to do with how deep into the ground that it can be located with a metal detector. Different kinds of objects have varying amounts of magnetic and electrically-conductive properties. Therefore, they affect metal detectors differently. Also, some detectors will sound-out on some kinds of objects better than others. As mentioned earlier, gold is not one of the better-reading metals, so cannot be picked-up with a metal detector as deeply as an iron object of similar size and shape.

Another factor which determines how deep an object will be picked-up by any detector is the size of the object itself. Whereas a 2-pennyweight nugget (1/10th ounce) might be picked up five inches deep into the ground with a certain metal detector, a 5-pennyweight nugget (1/4 ounce) might be picked-up eight inches deep into the same ground with the very same detector.

How much an object has deteriorated and has been absorbed into the soil is another factor in how deep the object will be picked-up. Iron objects tend to oxidize and become slowly absorbed into the surrounding material. This causes the target to appear larger and read-out more strongly, so it will be picked-up at greater depth with a metal detector. Once such a target has thoroughly deteriorated as an object, it will stop reading as a metal and start reading as highly-mineralized ground. Gold does not oxidize or deteriorate, so this factor does not apply to natural gold targets.

The size of a search coil on a metal detector is also a factor in how deeply the detector will locate objects. Larger coils generally are able to detect objects at greater depth than smaller coils. But they generally do not have as much sensitivity in detecting smaller gold targets. Smaller search coils have greater sensitivity to small objects, yet do not have the depth-probing capability that larger coils do. Medium-sized coils, from five to eight inches in diameter, often combine the features of having both a reasonable amount of sensitivity for the smaller objects, and acceptable depth-scanning ability.

One thing to keep in mind is that a larger coil will also increase the size of the area being covered by each sweep.

Many nugget hunters prefer to have a smaller search coil handy, because it produces the greatest small-object sensitivity (gold flakes), and because the smaller coils can get into tighter spots—like in and around tree roots and inside of exposed crevices in the bedrock, where nuggets are most likely to be found with a metal detector.

Almost all detectors today are made so that various-sized coils can be attached, depending upon what they are to be used for. When testing a detector, do not make the mistake of assuming that if the device sounds out well on a gold sample when using a coil of one size, it will also sound-out well when using a coil of a different size. Your best bet is to test the detector with the various-sized coils to see which work best for your particular needs.

One of the most important factors determining how deep a metal detector will sound-out on a gold object is how much mineralization (interference) is present in the ground that is being prospected. More minerals equal less depth. This is especially true of BFO detectors. Because black sands usually exist, and sometimes actually concentrate, within the very same streambeds or soils where gold deposits are located, metal detectors are not always used to directly detect gold in streambeds or material of substantial depth. They are sometimes used to scan places where there is a very shallow amount of gravel or material (if any) present over top of the gold (exposed bedrock).

One excellent use of the BFO detector as a prospecting tool is to locate concentrations of black sands in a streambed. Black sands often accumulate in the very same locations that gold does (pay-streaks). From your fundamental knowledge of placer geology, after potential pay-streak locations have been pinpointed, those specific areas can sometimes be scanned with a BFO detector to locate the increases in other heavy elements. Specific sites which sound-out heavily on the “mineral” setting can then be sampled by conventional gold mining techniques.

VERY LOW FREQUENCY DETECTORS (VLF)

The VLF detector is a more recent development in the field of electronic prospecting. Very Low Frequency detectors may come under other names or descriptive abbreviations such as VLF, GEB, MF, GCD and others. These are designed with circuitry which is able to cancel-out the effects which highly-mineralized ground has on a BFO detector. VLF detectors have the ability to look through or past highly-mineralized ground and detect metal objects (gold) that may not read at all on a BFO metal detector.

The VLF, being able to cancel-out interference caused by mineralized ground, is more suited for locating gold deposits and gold specimens directly. However, it still remains true that gold targets will have to be large enough, or located close enough to the surface, or deposits will have to be tightly concentrated enough, to sound-out on a VLF, just as with a BFO detector.

Just because a particular detector is of VLF design, does not mean it will sound-out well on gold. In fact, there are some VLF detectors which have difficulty in sounding-out on gold samples at all. So this type of detector must be just as thoroughly tested using natural gold targets before buying for prospecting purposes.

The VLF detector, being a mineralization-cancelling device, sometimes does not have the ability to detect the heavy black sand concentrations the way a BFO detector is able to. Consequently, a VLF is more often better-suited for scanning directly for gold, whereas a BFO is generally better-suited in helping the prospector locate gold deposits in an indirect sort of way, by finding the highly-mineralized ground within a gold-bearing area.

MULTI-PURPOSE DETECTORS & SPECIALIZED GOLD DETECTORS

VLF detectors are sometimes also constructed with discrimination circuits that are designed to cancel or identify specific types of targets—like bottle tops, aluminum foil and pop-tops. For the most part, this type of electronic circuitry is better-suited for treasure and coin hunters. When used in prospecting for gold targets, discrimination circuitry sometimes has a tendency to also reduce the detector’s depth-probing capability, especially in highly-mineralized soil or streambed material. Since gold targets are already difficult to locate, it can sometimes be better to not utilize additional circuitry which could hamper sensitivity towards gold.

However, some conditions do exist in which discrimination circuitry may assist a gold prospector. If using such a detector, always test it against a sample-nugget planted in or on the ground that you are probing, to determine whether or not you can trust the discrimination circuitry.

There is a lot to be said about having a small natural gold target along with you at all times when you are prospecting for gold with a metal detector. This way, each time you decide to try something new to try and get the most out of your detector under changing circumstances, you can confirm the results using a target which is similar to what you are hunting for. It is common for electronic prospectors to glue a test-nugget for this purpose to a poker chip, which can be tossed to the ground and easily spotted again.

Some of the newer, specialized VLF gold detectors are utilizing specific discrimination circuitry called “Iron Identifiers.” This does not necessarily reduce the total depth capability in the detection of gold targets. In other words, the circuitry will identify iron objects which are nearly certain to be iron. The downside to the use of such circuitry is that if an iron target is too deep or too small, it might still be identified as iron. Also, if the ground is highly-mineralized, the accuracy of iron-identifying circuitry is likely to be reduced.

The best gold detectors which use a meter or other display to identify different types of objects, do not route the discrimination function through the same circuitry that produces sound variations through the headphones. In this way, you can obtain optimum depth probing and object sensitivity to your ears, along with some added visual ability to pre-identify what is sounding-out on the detector. This is all about reducing the amount of trash targets that you must dig up while looking for gold.

Some experienced electronic prospectors utilize discrimination circuitry (turning it on and off accordingly) only after a target has been located. This way, depth and sensitivity is not forfeited during preliminary searching.

Other experienced prospectors insist that no discrimination circuitry is needed. Once you are familiar with the area you are searching, and know the specific audio tone changes of gold and/or trash targets, you will form your own judgment of which targets (sounds) to dig and which targets to leave alone. Different prospectors have different methods. Also, different locations often require different methods. Some experienced electronic prospectors simply dig every target (sound).

Some VLF detectors are made with circuits designed to analyze targets. This means they are able to tell you if the target is a nail, bottle top, a nickel, silver dime or a piece of gold. Such circuitry has only limited accuracy in electronic prospecting; because highly-mineralized ground tends to interfere with the signal and can give a false reading in the analyzer. Still, the added capability can be useful.

None of these circuits are a problem with multipurpose detectors, providing the special circuits can be shut off or bypassed—and/or providing the additional circuitry does not hamper the detector’s efficiency in locating gold and silver targets.

Some VLF detectors are designed with manual ground-balancing controls, and others are designed with automatic ground-balancing circuitry. Some prospectors prefer the manual controls. Others prefer automatic ground-balancing. There is nothing wrong with automatic ground-balancing circuitry in gold prospecting, as long as it is fast enough to keep up with the rapidly changing mineralized conditions of the different areas you intend to prospect—and as long as the additional circuitry does not hamper the detector’s ability to locate gold and silver targets.

Some VLF detectors have been specifically designed as gold prospecting tools. Since most specialized gold detectors operate at a higher transmitting frequency, have extensive ground-balancing capabilities, and have special circuitry to avoid sensitivity overload in highly-mineralized ground, they definitely do have some advantages in their ability to locate small gold targets over most multipurpose detectors—or gold targets which are deeper in the ground.

The high-performance of some of today’s specialized gold detectors even make pinhead-sized gold targets recoverable.

Which detector you choose to buy will depend upon what you plan to use the detector for. If you plan to only use it for prospecting purposes, a special gold machine is probably best for you. If you intend to search for coins, caches, artifacts and lost articles, as well as prospecting for gold and silver, perhaps a multipurpose detector is best—or two separate detectors. Only you can decide.

I would suggest you buy your detector from a dealer located in the general area where you plan to prospect for gold. The local dealer will know which detectors are performing best in that area. Local dealers will also introduce you to other prospectors, and perhaps a local prospecting and/or treasure hunting club or association.

Communication with local prospectors can be a very big help in determining which detectors are best for specific areas. You can also get tips from them on productive places to prospect with your detector.

No detector made is the best for all locations. Some machines work better than others in wet or dry conditions. Some work better in hot or cold climates. Some detectors are affected by alkali “salts” in the soil or gravel more than others. When any of these examples is the case, a smaller coil might manage adverse conditions better than a larger coil. Each area is different.

Another reason to purchase your detector from a local dealer is the help and support that you will receive. Success in the field comes from understanding the workings of your detector, and perhaps receiving inside information on good places to hunt. The money saved by buying from a discount mail-order house may not be worth the loss of support you would otherwise receive from a local dealer—especially when you are just beginning.

When buying a detector which you intend to use for prospecting purposes, keep in mind that probably the most important feature is the detector’s capability of cancelling the heavy ground mineralization found in most gold-bearing areas.

Practice makes perfect. You must start with good equipment. The rest will be up to you.

ELECTRONIC PROSPECTING DRILLS

The following is a set of drills put together to give the new (or old) owner of a metal detector some practice with his tool and to allow him (or her) to get a good grasp of what the detector’s gold-finding capabilities are:

DRILL No.1: Take a file or electric grinder to a piece of iron or steel (like a nail), and allow the fine pieces of metal to fall into a container. Pour some filings onto a piece of paper and pour some glue over the filings to hold them intact. Pour more filings on top of the glue and then pour on more glue. Continue this until the conglomerate is giving off a strong mineral reading on your detector. Make three different sheets of mineralization; one giving off a very mild mineral reading, one causing a medium signal, and one which gives off a strong signal.

If you are already an experienced gold prospector, and have some black sand concentrates lying around somewhere, use a magnet to collect some magnetic black sand and use these instead of iron filings. Sometimes, you can get prospecting supply outlets to send you a small package of black sand concentrates. You can also find bags of mineral concentrates (which usually include some gold) which various sellers on the Internet market as panning sands. These are better than using a machine to create iron filings, because they are the actual material that you will encounter in the field.

These different mineralized conglomerates will give you a good idea of how your detector will react to different degrees of mineralized ground.

DRILL No.2: Acquire at least a half-ounce of placer gold, preferably more, with a variety of fine, flake, and nuggets so a wide range of testing can be done.

Carefully place the gold in a pile on a clean sheet of paper in a location where there is no other metallic object reading on your detector. Scan the gold with your detector from varying distances to get an idea of your distance-capabilities when scanning a concentrated gold deposit.

Now spread the gold out over a slightly-wider space on the paper and scan again to check distance. Continue to spread the gold out wider and wider until it no longer reads on your detector—or until you are picking up on individual flakes of gold. This drill will give you a good idea of what sized pieces and accumulations of gold will sound-out at what distances. Try different coil sizes to see what their capabilities are.

Pay particular attention to the specific sound-readings that you get when scanning over gold targets. These drills should be done with headphones. With some practice, you will start to be able to tell the difference between gold and other metallic sounds by the difference in the strength, crispness and tone of the signal. Stronger-reading metals will give a sharper and louder change in tone, whereas gold tends to cause a softer and more indistinct signal–especially when located in smaller amounts or at a distance. Do the drill and see for yourself.

DRILL No.3: Using the flake-gold and nuggets in different accumulations, as done in drill No. 2, place the different sheets of mineralization over the top of the gold and note the responses on your metal detector. If you have a VLF, practice cancelling-out the mineralized sheets and test to see what size-accumulations of gold can be picked-up while doing so. Try more and more mineralization, combining the sheets together if necessary, to see how much mineralization your VLF detector will look through and still have sensitivity to gold targets.

Notice how even a larger piece of gold puts out only an inkling of a reading when covered by heavy mineralization and/or scanned from a distance. Recognizing these very light signals is usually the difference between success and failure in electronic prospecting!

If you are doing these drills with a BFO detector, try combining different amounts of mineralization with the various-sized accumulations of gold. Determine for yourself on your own detector how much mineralization it takes to block-out the different accumulations of natural gold.

I am certainly aware that sometimes it is difficult to come by a collection of gold flakes and nuggets if you don’t already have a collection of your own. However, the time spent in locating some natural targets to practice with, or in talking a friend into lending you his collection–or in talking him into doing these drills with you—will be worth many times as much time spent out in the field with your detector.

These drills will not teach you how to prospect for gold deposits. Only practice and experience out in the field will do that. But these drills will go a long way to familiarize you with your detector and give you certainty on the use of it. They will help you with the basics that you will need to learn to prospect for gold with a metal detector.

HELPFUL TIPS ON TUNING

Each model of detector has its own set of operating and tuning instructions which you should follow. And, I highly suggest you familiarize yourself with every aspect of the manufacturer’s instructions. In addition, here are a few pointers which have proven successful in the prospecting field:

Some manufacturers recommend that their volume-changing detectors be tuned to just below the hearing range. The purpose of this is so that the slightest reading will make a sound— which can be easily distinguished from the silence. But for prospecting purposes, it usually works better if you tune your detector so the audio signal is always within hearing-range. This will use up the batteries just a bit faster, but it is much better to be able to hear the signal at all times.

The audio threshold (“threshold”) of a tone-difference sounding detector should also be set just in the hearing range. When looking for natural gold targets, just the slightest change can mean the difference of finding or missing a gold target. Changes in volume and/or audio tone also are an indication of changes in ground mineralization and let you know when adjustments are needed to ground-balance again and again.

Sometimes the detector’s audio signal will drift off to a lower volume range due to temperature changes or loss of battery life. If the audio signal is tuned into the non-hearing zone and drifts into an even lower range, you might be scanning for several minutes without having the detector tuned properly. That would just be a waste of time.

Sometimes a warming coil will cause the threshold sound to drift upwards. A cooling coil might cause the threshold to drift downward. Hunting in and out of water environments, while scanning the banks of a stream, might cause threshold changes. You should make adjustments as necessary.

The main cause for a detector’s tuning to drift is loss of battery life. When this occurs, it is time to replace the batteries with a new set so you can get the best performance out of your detector—which is needed when hunting directly for gold.

It is always a good idea to bring along an extra set of batteries into the field when prospecting. Because when they quit, you are finished until new batteries are installed. Extra batteries should be kept cool and dry. Zip-lock baggies work well for this.

Prospecting for gold targets directly with a VLF detector should almost always be done in the “all-metal” mode.

Setting Sensitivity: It is important to stress that you do not want to set the sensitivity too high on your VLF detector while prospecting in a heavily-mineralized area. A high sensitivity setting while testing a nugget in the air will show improved perception—and therefore can give you a false impression of the detector’s scanning ability for gold targets in the ground. It is better to do your settings while scanning over your test-nugget on the ground that you will be searching over.

Turning the sensitivity up too high in mineralized ground is similar to using high-beam headlights in the fog. You get lots of flashback and irregular sounds and false targets. If your sensitivity is set too high, your detector will operate in an erratic manner. There will be many false signals which do not repeat themselves (“flashback”).

Consequently, less sensitivity can give you more depth-penetration in mineralized ground. There is actually a middle ground, depending upon ground mineralization, which will give you optimum sensitivity without too many “ground noises” which are confusing and prevent you from selecting the real targets. Try and run with the sensitivity as high as possible—until the steady tone of the threshold begins to give off an uneven, wobbly sound while you are scanning.

I usually do not recommend using the factory preset marks on your detector controls. Such settings are for average conditions. Prospecting for gold targets requires continuous adjustment to ground-balancing, and the threshold and sensitivity need to be set as accurately as possible to ever-changing conditions. You need to get the most possible out of your detector to avoid missing gold targets.

“Peak Performance” on a metal detector for nugget hunting purposes in most cases is: maximum volume on detector, threshold set in minimum audio hearing range, maximum sensitivity without receiving too much flashback, and ground-balance to the average ground being scanned. When you accomplish peak performance on your detector, the rest is up to you! By this, I mean you will have to interpret which signals should be dug up.

Ground-balancing: Setting the proper ground-balance on your detector, and keeping it properly adjusted while you search, is perhaps the most important factor in successful nugget hunting. I cannot overstate this point; because without proper ground-balance, you simply cannot find natural gold targets—unless you just get lucky. All of the skills we will talk about in this article, skills and methods which will make you good at finding gold targets, all depend upon your detector being properly ground-balanced.

Always set your ground-balance to the average soil or material which you are searching. You will find the majority of gold nuggets in average ground. If you ground-balance to specialized heavier-mineralized zones which are not the average matrix, you may forfeit some depth-probing capability or sensitivity to smaller or deeper gold targets.

Detectors which come with permanently-set, predetermined ground-balance are usually not especially good for electronic prospecting.

You should hear a low hum when your detector is turned on properly (threshold sound). As the detector is raised or lowered from the ground, the threshold hum should get louder or softer. This tells you what needs to be done to get a proper ground-balance. Handling the ground-balance knob or button on your detector is similar to handling the volume control of a radio. If the threshold hum is disappearing as you lower the coil to the ground, turn the knob up. If the hum gets louder as you lower the coil, turn the knob down. The basic idea is to adjust the ground-balance knob (or press the button) until rising and lowering the coil to the ground creates little or no change in the threshold hum.

Ground-balancing has to be redone on a regular basis while prospecting. The reason for this is because placer deposits do not contain uniform amounts of magnetic mineralization. Water-flows create low pressure zones and high pressure zones from one place to the next. These different zones accumulate different amounts of mineralization during flood storms. Often, you can see changes in mineralization just by noting changes in the color or surface of the ground you are scanning. Also, changing from gravel-like material to bedrock surfaces almost always changes the amount of ground mineralization. Get into the habit of re-ground-balancing about every 15 or 20 feet, or about every five minutes, or whenever the ground conditions change.

Your detector will tell you what is going on. If the threshold hum is getting louder, it usually means there is less mineralization in the ground you are now searching. If the hum goes softer, the mineralization is increasing. With a little bit of experience, you will gain your own perception of when it is time to re-ground-balance.

It is almost never a good idea to balance a detector over top of a piece of metal in the ground. Move around until you find a non-reading area to ground-balance.

When ground-balancing, move your coil all the way down to touch the ground if possible. I say “if possible,” because you occasionally run across areas with so much mineralization that you are not able to put the coil within a few inches of the ground! “Alkali salts” in damp soil can sometimes also create so much interference that the coil of your detector needs to be raised several inches above the ground to search for targets. Naturally, depth penetration is lost by doing this. But sometimes you have no other choice. Sometimes you can also get around this problem by making adjustments to your detector’s sensitivity. This will allow you to search with your coil closer to the ground; but the reduced sensitivity will likely eliminate some perception of smaller or deeper gold targets.

Sometimes, you can obtain better results by ground-balancing your detector a little on the positive side. A slight positive ground-balance increases the detector’s sensitivity to smaller gold targets when hunting in an area of lighter mineralization. This means that the threshold makes a slightly louder hum as the coil is lowered to the ground. When operating this way, be sure to keep the threshold in the audio hearing range. You don’t accomplish this by adjusting the threshold; reset the ground-balance as necessary to remain in the audio hearing range when lowering the coil to the ground. Just a slight positive ground-balance boost is all that is needed. Some experienced prospectors like to operate in a positive range all the time.

However, you may find instances when working around highly irregular ground, vegetation and/or rocks when a slight positive ground-balance creates a problem. Lifting the coil up and down and around with a positive ground-balance setting can create a similar situation as with too much sensitivity.

In highly-mineralized ground, when there are too many flashback signals which could be real targets, you can try ground-balancing your detector to a slightly negative setting with the coil on the ground. This may reduce your sensitivity to some of the smaller gold targets. But it is likely to settle-out your machine, and it might make it possible to locate targets which otherwise would not be accessible.

Always bring along your small sample natural gold target (about the size of a match head). This should be glued to a bright colored poker chip, or something similar, to keep it from being lost. Some prospectors go so far as to drill a hole and tie a string to the poker chip to avoid losing valuable time searching for lost poker chips! When in doubt about your tuning, toss down the sample gold target, cover it over with the ground in question, and see how your detector reacts. It might not be necessary to cover the test-nugget. Just placing it on top of the ground may be enough to test the tuning of your detector over that type of ground.

One thing which should be mentioned is that while you are searching around, your threshold hum is likely to change. The answer is usually not to reset the threshold; it is to adjust ground-balance and sensitivity as necessary to challenge the changes in ground mineralization. Your sample gold target will be the final test of whether or not your adjustments are working. If you don’t have a small natural gold nugget, you really should get one! Otherwise, a small piece of lead will create a similar target.

Other Tips on Tuning and Setting up a Metal Detector for Prospecting: When you are operating a metal detector, it is good practice to remove all rings, bracelets, watches and other jewelry from your hands and arms (ankles and toes). They can give a false read on the detector. This is especially true when you are testing a detector before buying, or when you are tuning your detector to sound-out properly on a special metal target while passing it over or under the search coil with your hand. Sometimes, belt buckles, canteens, knives and other digging tools or large metal objects carried on a belt can create false signals when using the more sensitive and specialized gold detectors. Even metallic eyelets on boots can cause problems when scanning too close to your feet. It doesn’t take much practice to figure out how to solve these problems.

Make sure to adjust the shaft-length on your detector to a comfortable position. Bending over too far will create uncomfortable back strain when hunting for extended periods.

Also, when the angle of the search coil on the shaft is changed to fit a new set of search conditions, the detector must always be re-tuned to correspond with the new relationship between the coil and the metal shaft.

Some prospectors prefer to mount the control box of their detector on their belt or hip. This lightens the arm-load during longer periods of prospecting activity.

It is also a good idea to wind the coil connection cable firmly to the shaft. This way, it is not flopping around, giving false signals or getting caught on objects and vegetation. Be careful not to pull the cable so tight as to break inner wires and create irregular operation of the detector.

OTHER IMPORTANT FACTORS TO CONSIDER WHEN BUYING

If you are looking over a metal detector you are interested in buying, test it to make sure that its tuning does not drift on its own. This test can be done by placing a good set of batteries into the device, turning it on, allowing it to warm up for a minute, tuning it in, and allowing it to sit and run for 5-to-10 minutes. If the audio tone drifts during this time, you ought to look around for a similar detector which has better electronic stability.

CAUTION: Wetness and dampness are not good for the control box of any type of electronic detector. Be careful to avoid getting yours wet when working around water. If you intend to use a detector out in the field on a damp or rainy day, you can cover the control box with a clear, loose-fitting plastic bag and secure it to the shaft of the detector. The bag should be loose enough so you can work the various control knobs without having to untie the bag and take it off to setup or re-tune the detector.

HEADPHONES

It is important in electronic prospecting to use quality headphones. This point cannot be over emphasized. Some detectors work just fine with the headphones which come from the factory.

There are different types of headphones. Some are heavy and cover the ears thoroughly. Some are light. What is best for you will depend largely upon the conditions where you are going to search. For example, the heavy type which thoroughly covers the ears might not be very practical in the hot, quiet desert environment. But they might work exceptionally well in a cooler environment—say along the bed of a creek where running water is making lots of background noise.

Areas which include the company of occasional rattlesnakes might require the use of lighter, less sound-proofed headphones!

The proper headphones for a specific hunting environment are another area where the local dealer or members of the local prospecting club can make valuable suggestions.

It is a common practice for prospectors to shorten the length of cable on detector headphones to about 3 1/2 feet. This helps prevent the cable from snagging on branches and other obstructions when working in brushy areas or climbing over uneven terrain.

Some detectors have volume controls and others do not. Volume on a detector while prospecting should normally be turned to maximum. Don’t confuse this with threshold hum, which should be set near minimum audio level. If maximum volume on the detector is uncomfortable to you, obtain a set of headphones which have volume control. Then, turn your detector’s volume all the way up and use the headphone controls to turn the volume down if you must.

Many electronic prospectors highly recommend “sensitivity enhancers”—like those made by DEPTHMASTER. These help enhance the soft target sounds from gold, while lessening the noisier signals caused by trash and iron targets.

OTHER HELPFUL EQUIPMENT

A plastic cup or tray is sometimes necessary to recover gold targets, even in dry terrain. A plastic gold pan is helpful to work down material where water is present. Sometimes a portable garden rake is helpful for moving smaller rocks and obstructions away from a productive hunting area. A small G.I. shovel is helpful in some hunting environments. A canteen filled with liquid; tweezers, needle-nose pliers for removing gold from bedrock traps; and a small pick for digging and scraping. Sometimes the ground can be very hard. This is especially true when finding gold on hard caliche layers in the desert. A wide belt with a carpenter’s loop (for holding hammers) comes in very handy for a small pick. This keeps it out of the way, but also makes it quickly accessible.

A lot of your gear can be left at your vehicle, or carried in a backpack which can be set down at the hunt site. It is usually better to not load yourself down too heavy while prospecting with a metal detector.

Many electronic prospectors are using empty 35mm film containers to contain recovered gold targets. These are unbreakable, and the large mouth makes it easy to get a piece of gold inside. Zip-lock baggies are also helpful.

A magnet can be a very big help while electronic prospecting. Sometimes you can recover a faint-reading iron target right out of the dirt with a pass of a magnet. Otherwise, you might find yourself losing valuable minutes picking through the material, looking for a small piece of gold. Animal feed stores commonly stock a special magnet used for cows (traps small iron particles, preventing them from entering and damaging intestines). These magnets are powerful, yet inexpensive. You can mount one on the end of your small digging-pick or tape it to the handle of a plastic or stainless steel garden trowel. This way, the magnet is handy when you need it. Some prospecting picks are available which already have a magnet attached; very convenient!

A serrated-edge on a garden trowel also is helpful when you find yourself digging around roots or brush. Some prospectors keep one edge of their trowel sharpened just for this reason.

When working bedrock areas, a small crevice tool can be a big help to open cracks and crevices which are sounding-out on your detector.

Some kind of pouch or pocket creates a location to dispose of small pieces of trash and iron which you dig up. You only want to dig it up once! It is much better to remove all small trash targets from the playing field. With the continuous improvement of electronic prospecting tools, you could find yourself going back over the same areas again at a later time!

Some prospectors are using fishing or photography vests—lots of pockets. These come lightweight or heavy, depending upon the environment where you plan to hunt.

 
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By Dave McCracken

“When to do a clean-up”

Some miners like to “clean-up” their sluice boxes after every hour of operation. Some prefer to do clean-up at the end of the day. Others will go for days at a time before cleaning up. This is all a matter of preference and seldom has much to do with the actual needs of the sluice box.

More commonly these days, a dredger only cleans-up the “high-grade” section of riffles in his or her dredge after each sample or at the end of a production day. That is a special small section of riffles which catch most of the gold near the head of the sluice. The full recovery system is usually only cleaned-up when enough gold has accumulated to make the effort worthwhile, or it is time to take the dredge out of the water.

There is a method of determining when a sluice box needs to be cleaned up, so that you can keep it operating at its utmost efficiency. If the majority of gold is catching in the upper-third section of the sluice box, then the recovery system is working well.

After a sluice box has been run for an extended period of time without being cleaned, the riffles will be substantially concentrated with heavy materials behind them. Sometimes an abundance of heavily-concentrated material in a sluice box can reduce the efficiency of the riffles. This is not always the case. Much depends upon the type of riffles being used and how they are set up in the box. The true test of when a set of riffles is losing its efficiency because of being loaded down with heavy concentrates is when an important amount of gold starts being trapped further down the length of the box than where it normally catches. When this occurs, it is definitely time to clean up your box. Otherwise, clean the box when you like.

Expanded-metal riffles, being short, will tend to load up with heavy black sands faster than the larger types of riffles. Still, a large, visible amount of black sand being present is not necessarily a sign that you are losing gold. Gold is about four times heavier than black sand. As long as there remains fluid action behind the riffles, the black sand might have little or no effect upon gold recovery. The best way to evaluate your recovery system is by direct observation of where the gold is being trapped.

DUMPING OFF

The concentrates which have accumulated in a sluice box can be removed by unsnapping the riffles, carefully removing the carpet underlay, and washing everything into a washtub or bucket. The contents can easily be rinsed out of the carpet underlay inside the washtub.

A medium-wide plastic putty knife can be very helpful in removing lingering concentrates from the high-grade section of a sluice box when that is the only place in the recovery system being cleaned-up.

The concentrates can then be screened into another wash-tub or into a bucket, depending upon what type of screens you are using. Classification of the concentrates into several sizes will allow you to process each more efficiently. The size-classifications that you want to use will depend largely upon how you will process the final concentrates. No matter how you process the final material, you almost always want to begin with a ½-inch or ¼-inch screen, just to eliminate all the larger-sized material from your concentrates. The following video segment demonstrates this preliminary screening, reminding you to carefully remove any gold nuggets which stay on top of the screen before discarding the larger-sized material:

There are several types of final clean-up devices on the market which can help you process the final concentrates, including different kinds of wheels, bowls and miniature sluicing systems. They all work pretty well when set up properly. Here is a video sequence demonstrating the use of a gold wheel to facilitate final clean-up:

Each device has its own instructions about the proper classification-size of concentrates for optimum performance. So you will want to buy or make your screens accordingly. The following video sequence demonstrates a second screening through a common sieve about the size of window screen – which is about normal for splitting concentrates into two sizes:

In my own operations, when we accumulate more than just a small amount of concentrates to clean-up, we have had very good results by first running the concentrates through a plastic Le Trap Sluice. First, though, we screen the concentrates through 8-mesh or 12-mesh screen to remove larger material. The following video sequence shows the Le Trap being used to help with a final clean-up:

Or, rather than use a special device (wheel, bowl, etc), you can work your concentrates completely or nearly down to the gold with the use of a gold pan. In this case, I would suggest that you first classify the material through 8-mesh (8 openings per linear inch) and then through 20 mesh (20 openings per linear inch) screens to break it up into three sizes: 1) the material which stays on top of the 8-mesh screen; 2) the material which passes through the 8-mesh screen but stays on top of the 20-mesh screen; 3) and the material which passes through the 20-mesh screen.

Under normal circumstances, the larger two classifications of concentrate will pan down to gold by themselves quite fast. Because of this, even a final clean-up device is usually only used in the field on that material which will pass through the smallest classification screen.

I have thoroughly demonstrated the panning process in a separate article, so I won’t repeat that here.

FINAL DRY SEPARATION

These final clean-up steps can be done at camp, preferably in a dry environment, where the wind is not blowing much and where there is a table top or some other flat surface available to you for a work space.

Important: Before you do the first step of this process, it is best to work your concentrates down as far as possible, to remove all of the black sands that you possibly can. The more black sand you can remove while the material is wet, the less you have to deal with after it is dried. Sometimes you can remove more black sand with the careful use of a finishing pan (small steel gold pan about 6-inches in diameter) inside of a small wash tub.

A Gold Extractor will allow you to work all of your gold down with no loss, and only about a tablespoon of black sands remaining.

Important Note: The best finishing device I have ever seen for working concentrates down to only about a tablespoon of remaining black sand, with zero loss of your gold, is called a “Gold Extractor.” Once your final concentrates are worked down to a very small amount of black sand remaining, you are ready to go on to the next step.

STEP 1: First dry out your final concentrates. This can be accomplished by pouring them into a small metal pan (finishing pan is best) and slowly heating them over an open fire or gas stove-whichever is at hand.

Dry out the concentrates.

CAUTION: Heating the concentrates from a gold mining program should not be done inside of a closed environment. Heating should be done outside and/or in a well-ventilated location, where any and all vapors given off by the various steps will be swept away from you and other bystanders.

You do not want to heat the concentrates too much at this stage. This is because they may still contain some lead. Excessive heat can melt the lead onto some of the gold within the concentrates. Pay attention to heat just enough to thoroughly dry out your concentrates. Be careful that boiling or bubbling during heating is not allowed to spatter gold out of the pan. The following video segment demonstrates this step:

STEP 2: Once the concentrates have cooled enough that they can be handled, they should be screened through a piece of window screen (about 12-mesh). A small piece of window screen, about 6-inches square, is handy to use for this purpose.

STEP 3: Take the larger-sized concentrates (the material which would not pass through the window screen), and pour them onto a clean piece of paper. If there is a lot of this sized concentrate, this step will have to be done in stages, handling a little at a time. Once the concentrates are poured onto the paper, it is easy to separate the pieces of gold from the impurities. The impurities should be swept off the paper and the gold should be poured into a gold sample bottle. This is where a funnel comes in handy.

STEP 4: Once the larger-sized concentrates have been separated, the remaining concentrates can be classified through a finer-mesh screen. A stainless steel, fine tea strainer (about 20-mesh) works well for this. Tea strainers can be found in just about any grocery store.

STEP 5: Take the larger classification of concentrates from the second screening, pour them onto a clean sheet of paper, and separate the gold from the impurities in the same way that it was done with the larger material in Step 3 above.

Use of a magnet on each size-classification of concentrates can be very helpful to remove those impurities which are magnetic.

Some prefer to use a fine painter’s brush to separate out the non-magnetic impurities. Separation can also be accomplished by using your fingers. This step goes faster if you only do small amounts of concentrate at a time. Pour the gold recovered in this step into the gold sample bottle.

STEP 6: Take the fine concentrates which passed through the final screening and spread them out over a clean sheet of paper. Use a magnet to separate the magnetic black sands from these final concentrates. The magnetic black sands should be dropped onto another sheet of clean paper, spread out, and then gone through with the magnet at least one more time. The reason for this is that some gold can be carried off with the magnetic black sands. They tend to clump together. Once the magnetic black sands have been thoroughly separated from the gold to your satisfaction, pour them into your black sand collection. There may still be some small gold values left with them which can be recovered by other methods at another time.

NOTE: There is a really nice set of final clean-up screens on the market that are made just for the purpose of separating your final concentrates into the ideal size-fractions for final dry separation. I highly recommend them, because they separate your final material into multiple size classifications which make the final dry process go even faster.

STEP 7: Now, all that should be left is your fine gold, possibly some platinum, and a small amount of non-magnetic black sand. These final black sands can be separated by blowing lightly over them while vibrating the sheet of paper. Since the sand is about 4 times lighter than the gold, it will blow off the paper a little at a time, leaving the gold behind. Once all the black sands are gone, you can pick out the pieces of platinum if present, and separate them from the gold. Pour the gold into the same gold sample jar used in the earlier steps.

This dry process (Steps 1-7) goes very quickly if an effort was made during the final wet stages to get as much black sand and other waste material as possible separated from the gold.

CLEANING GOLD

Sometimes placer gold just out of a streambed is very clean and shiny. If this is the case with your gold, after the final dry cleanup procedure is completed, your gold is ready to be weighed and sold or displayed or stored away in a safe place.

Sometimes, gold will come out of a streambed with some impurities attached to it. When this happens, it will be necessary to perform a final cleaning process to make the gold’s natural beauty stand out.

If your gold is not clean and shiny, and you want to get it that way, place it in a small non-breakable water-tight jar about half full of water and add a little dishwashing liquid. It does not seem to matter what kind is used. Fasten the top on the jar and shake the contents vigorously until the gold changes to somewhat of an unnatural glittery color. Sometimes this happens quickly and sometimes it takes a little longer. This mostly depends upon how much gold is in the jar. The more gold, the faster the process. This is because it is the friction of gold against gold which facilitates the cleaning process. Once the gold is glittery, rinse the soapy water out of the jar, pour the gold into a small (metal) finishing pan, and heat it up (outside and down wind) until the gold takes on a deep, natural, shiny luster. It is important to make sure that all of the soap has been rinsed away from the gold using clean water before you dry the gold.

Gold has a tendency to turn a dull color after having been stored in an airtight container for an extended period of time. For this reason, some gold miners and dealers store their gold in water-filled jars, and dry it out just before displaying it or making a sale.

If you should happen to store your gold in an airtight container and notice that its color does not seem to be as bright as it once was, wash it with soap and water and re-heat it, as in the above steps. This process will bring back the beautiful color and luster of the gold.

The best time to weigh your gold to get the most accurate measurement is after you have completed all of the final cleanup steps.

SELLING GOLD

There are numerous markets where you can sell your gold. Refineries will pay you for the fineness (purity) of the gold itself and subtract a few percent for refining charges. In this case, you will receive a little less than the actual value of the gold. Refineries usually will not pay for the silver and platinum contained within your placer gold unless you are delivering it in large quantities. Refineries prefer that you bring your gold to them in large amounts. They will often charge less for refining, and sometimes pay just a bit more for the gold, when it is brought to them in larger quantities.

Flakes of gold and nuggets have jewelry value on a different market. If marketed to the right buyers, flakes and nuggets can usually bring in more than a refinery will pay-or sometimes even much more.

If you are in gold country and ask around, you can nearly always find someone who is buying placer gold from the local miners. These individuals usually pay cash. Unless the fineness of the gold within the area is lower than normal, there is no reason to settle for less than 70% of the market-value of the gold for that day. This means that the gold is weighed and the buyer pays you for the weight of what you deliver. Impurities are never calculated into this type of deal. If you enquire around, you can usually find someone who is willing to pay 75% of weight. Sometimes you can find an 80% straight-out buyer-which is good.

There are also people out there who are ready to gyp you out of your gold if they can get away with it. It is wise to bring your own pocket calculator along when dealing with a new buyer.

If you go to a dealer who starts figuring a certain percentage of the fineness, and his final figures end up lower than a straight out 70% of the bulk weight of your gold as it is, go find another dealer. This is not to say that 70% is the going rate. You can do better if you look around. Although, you should never have to accept less than 70% of the going market price for your gold. If a dealer starts to tell you all sorts of reasons why your gold is not worth what you want for it, go find someone else. There are plenty of gold buyers around who will at least admire your gold. So there is no reason to hang around and listen to someone who is trying to steal it from you.

Local miners will know who pays the most! Or go up on our web forum and ask. Someone there is sure to turn you onto a good deal!

Cleaning your gold well before you take it somewhere to be sold can help a lot.

Sometimes dentists will give you a good price for your gold, and a phone call or two can pay off. Also, some lawyers and businessmen like to invest in gold. Sometimes you can get up to 100% of spot for your fines (fine gold) when dealing with them.

Some jewelers will pay well for your flakes when they have a demand for them. It is not uncommon to get as much as 90% or better when you make such contacts.

The best way to get top dollar for your gold is to do a lot of inquiring, always with the intention to find more and better markets. Then, when you need some cash, you can sell to the buyer who pays the most.

 

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