Panning for Gold, Diamonds, Rubies and Sapphires

Panning for Gold, Diamonds, Rubies and Sapphires

One of the first faceted iolites from gemstones found in
Wyoming by the author.

For those of us who are mechanically declined, gold pans are great: no buttons, meters, scales, batteries or electronics. They provide a break from today’s ubiquitous computers and electronics that frankly get on my nerves. Ever go out to dinner just to see all of the people around you texting on their phones and ignoring their company. Yes, I would just like to grab a few of those people by the earlobes and take them out in the field to pan for gold.

During the 1849er gold rush in California, more than 118 million ounces of gold were found by gold prospectors. Many of these discoveries began with prospectors simply using tin plates. When they found gold in their pans, they starting looking up slope for lodes filled with gold. Those who used diligent prospecting methods often found the source of the gold. In those days, panning had two purposes: to search for gold and to clean a dinner plate.

Gold panners on one of my field trips along the Middle Fork of the Laramie River in Wyoming. No one found gold, but they learned to pan, got some good sunshine and air, and several recovered diamond indicator minerals in their pans. Diamond indicator minerals included minerals unique minerals that erode from diamond pipes.

So did the 49ers find all of the gold?  Nope, they only found the easy lodes. Remember, a lot of their gold came from placers and placers eroded from nearby lodes. It is likely the prospectors depleted many of the better placers, but they barely scratched the surface of the lodes!  After searching for gold in Wyoming, it is apparent hundreds of gold deposits have been overlooked not only in Wyoming, but all over the US. We found gold all over southern Wyoming not only adjacent to Interstate-80, but even in the Laramie City landfill – all places no one had ever thought to look!

A book on how to identify and find
gemstones has already led to new
discoveries of opal, diamonds, rubies,
sapphires, peridots and potentially
diamondiferous host rocks by its readers

Today, the “Golden State”, home of the “Forty-niners”, divorced its heritage and chose bankruptcy over mining. Not a bright thing to do, but California’s politicians have never been accused of being smart. Not only that, California no longer allows people to use hobby dredges to dig for gold, even though the state was built on gold mining. Hobby dredges are essentially harmless, but Uncle Al and his followers find if anyone makes money besides them, then this is wrong.

One of more than a hundred field trips led by the author to

teach the public how to prospect for gold, diamonds and

other minerals.

More than 118,000,000 ounces of gold and 600 diamonds were recovered in the past! At today’s price, all of that metal would be worth more than $200 billion! Enough to pay off some IOUs. Even though all of that metal was mined in the past, as an exploration geologist, I know where there once was gold, there still is gold hidden near the surface, along trends, and even within the old mines. Usually many times the amount of gold mined in the past.

And where did those diamonds come from? No one has yet found the source of the diamonds accidentally discovered by old gold miners. In the 19^th century (as today) few prospectors had knowledge of what diamonds looked like, particularly since the great diamond rush in Kimberley South Africa, didn’t take place until 1871, twenty-two years after the great Californian gold rush. And it is likely thousands of diamonds were mined with the Californian gold and were rejected with quartz in the mine tailings, simply because the prospectors had no idea what the diamonds were. The diamonds from California ranged from less than a carat to one that weighed 32.99 carats (Hausel, 1998; Erlich and Hausel, 2002). It is important to keep diamonds in mind while prospecting for gold, because some are worth thousands of times more than an equivalent weight of gold (after faceting). And many collectors pay premium prices for raw natural diamonds from unique locations.

While panning for gold, one often sees curious bystanders.

These are not the only gemstones that have been found in California or elsewhere in North America. A few years ago, while searching for diamonds in California, I recovered several beautiful light-blue benitoite gemstones from panned concentrates taken in the Sierra Nevada Mountains. Benitoite looks very similar to sapphire. Further north in California, I also recoveredpyrope garnet and chromian diopside.

In Wyoming, we recovered gold from many areas where gold had not been reported. But we also found gold right in the middle of areas where people had mined gold in historical past. In addition to precious metals, we found gem-quality garnet, chromian diopside, ruby and sapphire in streams, and a few placer diamonds were also found in streams by others. Some of these gemstones were even recovered from ant hills along with peridot gemstones. So there is still much to be found, even with a gold pan.

When I was a geologist working in Wyoming, I visited hobby dredgers in the Douglas Creek district in the Medicine Bow Mountains to see what they were finding in their black sands. While observing the dredgers, I noticed the trout played with their suction hoses as they kicked up sand, mud, and nutrients: if you want to see a school of fish, you will always find them around these hobby dredges. And it doesn’t take a genius to realize that when it rains, or during periodic flash floods, or during spring runoff from snow melt, Mother Nature dumps more dirt and mud into the creek than a million hobby dredgers could ever. Even so, prospectors are always blamed for environmental damage from naive regulators whether real or imagined. I found that nearly every regulator in Wyoming was either a member of an environmentalist group antipathetic to mining and the American way of life, or already had their minds made up. One of the worse bastions of radical environmentalists was in the forest service. Why are all of these people so dead set against others enjoying their lives and making a little money?

Gold from Douglas Creek recovered from a hobby dredge and displayed in a space-age plastic gold pan by Paul Allred. Note the tiny red mineral sitting on a flat nugget. This is a pyrope garnet, or one of a group of diamond indicator minerals that geologists attempt to use to trace upstream to the source diamond pipe that it originated.

At one location on Douglas Creek, a prospector displayed gold in a pan. The gold was nice, but my eye was drawn to a small, rounded pyrope garnet. Diamond prospectors use pyrope as a guide to diamond deposits, since most erode from kimberlite pipes.

My field assistant and I had identified some cryptovolcanic structures upstream from this find on Douglas Creek and we wondered if these were unusual structures were the source of the pyrope garnets. Cryptovolcanic structures are circular structures with distinct vegetation anomalies similar to many known diamond deposits in the region.

Further upstream, a prospector had recovered two gem-quality diamonds with gold in a long-tom built in the side of Cortez Creek. The source of these diamonds has never been identified. At another location in the Medicine Bow Mountains in the Middle Fork of the Laramie River near the town of Centennial, people on one of my geology field trips recovered dozens of pyrope garnets in gold pans as they learned to pan: no gold – just a lot of diamond indicator minerals!



One of many cryptovolcanic structures found in Colorado, Montana and
Wyoming. This one (the depression) is actually a diamond-bearing
kimberlite pipe found in the Colorado-Wyoming State line district.

I never thought I would see the day, but there has been talk of banning gold panning in California. After years of panning for diamond indicator minerals in streams in search of diamond deposits, the only damage I can even imagine one might accomplish with a gold pan is develop stiff knees and lower back pains a trip to a chiropractor. Banning hobby dredging is bad enough, but is more like banning Tonka Toys to keep kids from digging holes in sand piles.

Even so, you will never get rich with a pan. A gold pan is simply a tool to assist in finding the ‘Mother Lode’. The more popular pans are space age plastic pans that you can buy at most sporting goods stores. These are a easier to use than the old tin pans, and the darker ones are good for high-lighting gold.

When you start panning, get comfortable. You might take off your shoes and socks, put your feet in the water, or wear water proof boots as you pan, but find somewhere you can sit down.

Placer gold from Gerald Stout recovered on Rock Creek near 
Atlantic City in western Wyoming displayed in my space age plastic gold pan.

To speed up the processing, a small shovel is useful to dig mud and dirt from the stream or bank. Stream banks should not be ignored because they were deposited by the stream – and if gold occurs in the creek, it will also be found in the bank. It is not necessary to use anything other than a gold pan, but I found using a sieve speeds up the processing. When you buy a gold pan, also buy a Grizzly pan (also referred to as a classifier) to place on top of your pan. If you are in bear country, remember there are two kinds of grizzlies (a sieve and the kind that will eat you). In Alaska (and other localities in the West), not only can bears be a problem but mosquitoes have been rumored to periodically take down moose. So be prepared for weather and the creatures you might encounter, particularly when you will be distracted by panning.

Panning is simple and obeys the laws of physics and fluid dynamics. The specific gravity of pure gold is 19.3 or 19.3 times as heavy as an equal volume of water; thus it is notably heavy and will stay in the gold pan as you wash out other minerals. Many black sand minerals have specific gravities that range from 3 to 6. One of the more common minerals in your black sand is magnetite which has a specific gravity of 5.2. Because of this, it is also helpful to have a strong magnet that you can cover with a paper towel or some other material, to run through the black sand concentrates in your gold pan, especially if you are looking for gemstones. This is unnecessary for gold because the gold will be very obvious once you find it. You can learn more about various minerals from a variety of mineral identification guidebooks.

The lighter-colored material with lower specific gravity in your gold pan consists mostly of quartz, feldspar and mica. Quartz has a specific gravity of 2.6 to 2.7; feldspar 2.55 to 2.72 and mica 2.7 to 3. So these light-colored minerals should wash out of a pan fairly easily. Another white mineral that is periodically encountered is scheelite. It has a high specific gravity (5.9 to 6.1) and drives prospectors crazy who often think it is ‘heavy quartz’ that they cannot pan out without losing all of the black sands. So, if you have a lot of so-called heavy quartz, you might check to see if you are near any old tungsten mines – scheelite is a calcium tungstate and will glow light-blue under short wave ultraviolet light (Hausel, 2006, 2009).  

When permeated with water, gravel and soil will tend to behave like a liquid. Stirring of the dirt in the pan with fingers will assist in sieving. To begin, fill the grizzly with gravel and place the entire pan under water working the fine-grained material through holes in the grizzly. Now take out the grizzly and examine pebbles on the sieve. If there is nothing of value, place this waste material in a pile on the stream bank (this will be a measure of how much you can pan in an hour or a day – you will likely be surprised at how little you can pan). The material sieved by the grizzly should be sitting on the fly screen in the pan. Work the very fine material through the fly screen.

Some of the many hundreds of gemstones found in Wyoming

since 1977.

Take the screen out and place in on the bank for later panning after processing the finer-grained material that slipped through the screen now sitting in the pan. Keep 1/3 to ½ of the pan under water with about a 30^o tilt away from you. Wash the lighter material into the creek using circular to elliptical motion. Don’t worry about panning too hard or fast, it is difficult to lose gold as it is seven times heavier than all of that quartz, feldspar and mica. If you are looking for diamonds andother gemstones, pan easier because they are not so heavy. For example, diamond has a specific gravity of 3.2, and should end up with the black sands (magnetite, zircon, ilmenite, etc). Continue panning until all of the light minerals pan out into the stream. You should now have ‘black sands’. Search these for gold and gemstones.

If the black sands have no apparent gold, start a rhythmic slapping of one edge of the pan with one hand while holding the pan with the other while you still have a little water in the pan. If you have any gold, it will separate from black sand along the edge similar to what is known as a Wilfley Table.

With a 10-power geologists’ loupe, examine the gold. A common mineral mistaken for gold ismica. Mica has a low specific gravity (2.7 to 2.9). Even so, it is difficult to get out of your gold pan and will tend to stay in the pan because of its nearly two-dimensional crystal habit. It forms flat flakes that cut through water. Many prospectors have a tendency to let their imaginations run wild until they get use to seeing gold and mica. While panning, mica will tend to roll over and over in the water while gold will sit tight.

Pour the water out of the pan, wet your finger with saliva and touch any gold flakes or dust and place them in a tiny vial for safe keeping. Examine the gold either with the loupe or microscope. If you have pristine gold flakes with rough and jagged edges (like corn flakes) the gold came from a nearby lode (rock found in place in bed rock), such as a classical quartz vein. Gold is very malleable and will ball up into a rounded grains or nuggets over very short transportation distances in a stream (Hausel and Hausel, 2011).

Somewhere nearby Oregon Buttes at South Pass in western Wyoming is a giant treasure awaiting discovery. This old rusty tin gold pan contains many gold flakes recovered from a placer and paleoplacer that some suggest eroded from a belt of granites in the Wind River Mountains 25 to 40 miles to the northwest. This is unlikely. In the center of the photo is a small dish containing cornflake gold that is very jagged and did not transport more than a few hundred yards from its source. The US Geological Survey estimated that, based on the volume of fanglomerates in this area, there could be as much as 28.5 million ounces of gold. The source of this gold remains unknown to this day (photo courtesy of the late J. David Love).

If the gold is rugged and jagged, you should be on a treasure hunt searching upstream (or up slope) for the source. In 1988, I worked for a company in Alaska and our team found small, jagged, corn flake-like gold in a group of streams draining a large area, so we started searching and found a very large lode deposit. The deposit, now known as Donlin Creek, was described by the Northern Miner in 2012 as “…quite possibly the most important project in the world today”. Our search for gold led to the discovery of a giant deposit that now has drilled resources of about 40 million ounces, equivalent in size to the famous Homestake Mine. At today’s gold price, this is $70 billion in gold. But a couple of things to note. This treasure was discovered in 1988. It is still sitting in the ground and may not be mined until 2015 or later, 27 years after we discovered it and none of us will benefit from the mining of the gold. Why does it take so long to mine treasure after it has been found? That is a good question and there are many complex problems with developing mines.

Using your geologist’s loupe, look for tiny, equal-dimensional pink, red, orange and purple mineral grains in the black sands. These may be garnets. If they are clear and larger than about 4 millimeters, they could be facetable, particularly by specialized gem cutters in Sri Lanka and India. While searching for specific kinds of garnets in Wyoming, we found a few hundred anomalies that produced garnet and other gemstones which eroded from hidden diamond pipes somewhere upstream. The source of the garnets remains unidentified and suggests that someone, someday, might find many diamond treasures in the hills of Colorado and Wyoming.

Quartz from the Seminoe Mountains all containing minor specs of gold (note the circle on the sample right of the pencil). This may not look like much gold, but when you see visible gold, the sample will assay better than 1 ounce per ton!  One of these samples was assayed and yielded 2.87 ounces per ton in gold!

In one location, near what is known as the Miracle Mile along the North Platte River north of Sinclair, Wyoming adjacent to the Seminoe Mountains, we recovered many pyrope garnets from eroded and hidden diamond pipes as well as gold in the gravels high and dry and a few miles from the river. The gold and garnets (and likely diamonds) in this area occur in what geologists call paleoplacers (fossil stream deposits). The lode source for the gold likely eroded from gold-bearing veins at Bradley Peak to the west of the gravels. The source of the diamond indicator minerals remains unknown. In addition to possible diamonds in this area, one has to consider where did all of that paleoplacer gold come from? Did it all come from Bradley Peak in the Seminoe Mountains? Or did it come from somewhere else. Personally, I like the Seminoe Mountains. I found several nice specimens of quartz with visible gold in this area and started a gold rush in 1981 (Hausel, 1995). I also believe that one creek in this area (Deweese Creek) likely has many nuggets and gold flakes in it. When I explored this area in 1981 and mapped it later, I could find no evidence that Deweese creek had been explored.

Note the 6-sided cross-section of this reddish purple mineral
next to the nickel. It is a ruby!

While looking for diamonds in the Laramie Mountains in eastern Wyoming, we recovered many tiny rubies and sapphires from our gold pans west of Wheatland and west of Iron Mountain. Ruby and sapphire have a distinct crystal habit and should be easily recognized in your gold pan. They form hexagonal prisms (6-sided prisms) or hexagonal plates (cross-sections) with three directions of parting.  Parting is simply an atomic imperfection that sometimes shows up as distinct, parallel lines in many crystals. It is the same imperfection that diamond cleavers used for many years to facet large diamonds.

While looking for the source of these gemstones, I found a deposit of ruby and pink sapphire at Palmer Canyon west of Wheatland. This deposit also had other gems that included thousands of carats of sky-blue kyanite and blue to purple iolite (water sapphire).

Over the next few of years, I found a half-dozen ruby deposits, a giant iolite and kyanite deposit at Grizzly Creek, iolite at Ragged Top Mountain and also at Owen Creek in the Laramie Mountains and a deposit with millions of carats of kyanite. Some of the iolite at Grizzly Creek weighed many thousands of carats. One I carried in a backpack weighed more than 24,000 carats – the largest ever recorded. But much, much larger iolite gems were left in the outcrop!

Gem-quality garnets found in Wyoming and faceted in Sri Lanka.

The Orange River of southern Africa is well known for placer diamonds as are places in Brazil. In North America, there has only been a few placer diamonds reported outside of California. But based on the many diamond indicator minerals found in Colorado and Wyoming (as well as 120,000 diamonds mined from kimberlite rock) and the more than 100 kimberlite pipes in this region; it is surprising that more stream-deposited placer diamonds have not been found. The largest reported placer diamond from this region was 6.2 carats found in Fish Creek on the border of Colorado and Wyoming south of Laramie. The largest diamond found in a kimberlite 

in this region weighed 28.3 carats.

Vein (lode) deposit seen in back (roof) of mine in California.

The geology of the area (Colorado-Wyoming State Line district) indicates hundreds of thousands of tons of diamond-bearing kimberlite eroded in the past. This material with its hundreds of thousands of diamonds was carried downstream in creeks and rivers south of the state line. Yet, it is extremely rare for anyone to report finding diamonds in the creeks. I suspect it is because of the lack of historic gold prospecting in the area, but someday, someone will find a rich cache of diamonds and start a rush. One prospector from Fort Collins use to find diamonds in Rabbit Creek while searching for gold, but he was possibly the only one who ever searched for gold and diamonds in the creeks of the area. Diamonds are easy to recognize once a person gets use to their appearance. They look greasy and are often equal dimensional forming what is known as a octahedron (8-sided crystal) or a modification of an octahedron.

Gold nuggets are a great treasure. Many are worth more than the price of gold and most have eroded from nearby lodes. The earliest reported discovery of gold in the US was in North Carolina. Nuggets were found along Little Meadow Creek including a 247.6 troy ounce nugget discovered in 1799. More than 1.2 million troy ounces of gold were produced from North Carolina over the years. Little Meadow Creek produced so many nuggets that it was called ‘the potato patch’ in reference to large nuggets.

Not long after the North Carolina discoveries, gold was found in Georgia. A gold rush in Dahlonega in 1829 resulted in as many as 500 gold placers and lode mines. Many nuggets were recovered including those of 54, 42, 40, 35, 26, 25, 19, 18, 15, 11, 6, 5, 4, 3 and 2 troy ounces. These were found in Gilmer, Habersham, White, Cherokee and Lumpkin Counties.



Nuggets from the Kuskokwim Mountains in Alaska: 
the largest is about one troy ounce.

Alaska has been a good source for nuggets. The largest was discovered in 1998 in Swift Creek near Ruby in central Alaska. The softball-size nugget, known as the Centennial nugget, weighed 294.1 troy ounces. Another large nugget found on Long Creek near Ruby weighed 46 ounces. Large nuggets were also found on Anvil Creek near Nome in western Alaska that included nuggets of 182, 107, 97, 95 and 84 troy ounces.

In northern Alaska, nuggets of 146, 137, 61, and 55 troy ounces were found in the Hammond River within the Brooks Range near Wiseman. In the same region, a 42-ounce nugget was found in Nolan Creek in 1994. The Gaines Nugget (122 troy ounces) was found in the Kuskokwim of southwestern Alaska near McGrath.

Another nugget, known as the Chicken Nugget, was found in Wade Creek near Chicken in eastern Alaska in 1983. This weighed 56.75 ounces. A nugget of 56 ounces was found on Dome Creek near Tolovana in central Alaska and a 52-ounce nugget was found on Lucky Gulch (Valdez Creek) near Denali in central Alaska.

 Arizona has produced many gold nuggets, but these are small compared to Alaska and California. This is likely due to the lack of active streams although many are found in alluvium and fanglomerates along the sides of hills. A few of the better known places for nuggets in Arizona include the Potato Patch at Rich Hill in the Weaver Mountains and the Greaterville placers south of Tucson in the Santa Rita Mountains. Several nuggets were discovered in the Greaterville placers including one that weighed 37 ounces. Some of the nuggets in this district are reported to have had galena attached to the precious metal. Galena is a very soft, lead-sulfide mineral with perfect cleavage and will break down over a very short transportation distance. This along with angular blocks of rhyolite and granite in the placers supports that the Greaterville nuggets have a proximal source and likely eroded from nearby silver and galena-rich quartz veins.

In the Weaver Mountains, samples of quartz with visible gold are often found with nuggets. Gold in the nearby Bradshaw Mountains has been found in Lynx Creek, French Creek, Big Bug Creek, and the upper Hassayampa River. Based on the geology and location of gold nuggets found in Arizona, several gold deposits have likely been overlooked.

Large nuggets were mined in Montana at Alder Gulch and California Gulch near Phillipsburg in the southwestern portion of the state. In 1902, a football-size nugget of 612.5 troy ounces was recovered from California Gulch. This was followed by discovery of a 77 troy ounce nugget from the same gulch. The largest nugget found in Colorado weighed 160 troy ounces and was named Toms’ Baby found in 1887 on Farncomb Hill at the head of the French Gulch placer near Breckenridge.

The largest nuggets found in the US were from California. At Carson Hill in Calaveras County, a nugget weighing 2,340 troy ounces was recovered in 1854. Another water worn nugget of 648 troy ounces was found at Magalia, California in 1859. Both of these were too large to have transported any distance.

The largest nugget from Wyoming weighed 34 ounces. There was an very interesting reference to a boulder in Rock Creek at South Pass that contained an estimated 630 ounces of gold. If so, this nugget with attached quartz was likely the size of a football. Many nuggets were also recovered from Carissa Gulch.

So as you are looking for gold and other treasures with a gold pan, keep in mind how valuable gemstones can be. Gold is very valuable, but some pink and red diamonds have sold for as much as $1 million per carat. A carat is tiny compared to an ounce of gold and some of these diamonds have sold for many thousands of times the value of an equivalent weight in gold.

GOLD RUSH WYOMING!

GOLD RUSH WYOMING!

It's hard to believe that it has been more than three decades since I discovered gold in the Rattlesnake Hills in central Wyoming and classified the new gold district as an Archean (more than 2.5 billion years old) greenstone belt. The gold in this district is similar to the rich deposits mined at Cripple Creek, Colorado.

One of the first gold discoveries in the Rattlesnake Hills - a deposit that was named Lost Muffler after I left the muffler to
 my 1975 Ford Bronco on the outcrop getting into UT Creek.

Some questions that need to be asked: (1) Where did the time go? (2) How come the incredibly attractive gold deposits comparable Cripple Creek have not been made into a mine? (3) Why doesn't the State of Wyoming get off its duff and make this a show piece and financial attractive gold play to attract hard rock gold miners to Wyoming? (4) Gold was found in exhalites, veins, stockworks and breccias and also predicted to occur in contact metasomatic deposits related to the intruding Tertiary alkalic volcanics into the greenstone belt rocks and adjacent limy rocks in the sediments - so how come more drilling hasn't occurred in this district? (5) Whatever happened to those giant gemstone depositsfound in Wyoming? and (6) How come the former Survey Director isn't in jail?

Goat Mountain Tertiary instrusive into the greenstone belt rocks. In foreground is
one of several gold-veins found by the author.

The first four questions pertain to gold in the Rattlesnake Hills. After I found gold in this district and started a gold rush in 1982, I thought this area would one day have a gold mine. But I also thought the mine would have been developed by 1985 or 1986.

Prior to this discovery, I started a gold rush in 1981 in the Seminoe Mountains. But that area has never really been explored and was tied up for years by a promoter who was interested in making too much money for the property. I also started a mini gold rushes to Purgatory Gulch in the Sierra Madre in 1988, Garrett along the western flank of the Laramie Range in 1989, Mineral Hill in the Black Hills in 1990, Puzzler Hill in the Sierra Madre in 1995 and several rushes to South Pass in the 1980s and 1990s. But then there was the giant of giant deposits that a group of geologists(including me) discovered at Donlin Creek, Alaska.  How is it that none of these have yet been made into mines? Isn't because there isn't enough gold! Nope! Take a look at Donlin Creek - it only has about 43 million ounces of gold worth $tens of billions.

My map board sitting on one of the gold-bearing stockworks I found in the district.

Then again there is the Pebble porphyry deposit. Had nothing to do with the discovery of that one - but it is a big one and estimated to contain gold, silver, copper and other metals that dwarf the Bingham pit in Utah. It is estimated to be about 2.5 times larger!  So how can world-class gigantic mineral deposits like Pebble and Donlin Creek sit for decades and not turn into mines?

gold-bearing breccia with my map board

Government doesn't work! And when it does, it works against us. When was the last time you found a government employee who was willing to help you? When was the last time you saw a government employee actually working? All government agencies (especially government division heads and directors and Congress for that matter) should be placed under a Sunset law by Congress and every 2 years they should be able to prove they have benefited the public and cut costs. If not -  hit the delete button and get rid of them! It this were to happen, it wouldn't take long and the list of government agencies would quickly diminish, we would have a balanced budget, and the few remaining agencies would learn how to work and work with the people who are paying their salaries.

Gold-silver-copper vein from Pickwick prospect, Absaroka Mountains.

Sorry, got off on a tangent. Back to geology. Wyoming is an extreme anomaly. The state produced considerably less gold than all of the other western states, yet it sits in the middle of craton. Cratons usually have considerable gold (as well as diamonds, nickel, platinum group metals, etc). So where is all of that gold hiding? Well a good part of it was taken from the public by the Federal government!. Yep, those extraordinary gold-silver-copper deposits in the Absaroka mountains and Yellowstone were taken from the public as were all of the copper-zinc-gold-silver volcanogenic massive sulfide deposits in the Sierra Madre Mountains. But it didn't stop there. The great Carissa gold mine at South Pass was taken from the public by the State of Wyoming as has been much of the South Pass greenstone belt.  Then there was the taking of the gold-silver-palladium-platinum deposits associated with the New Rambler mine, the Lake Owen layered complex and the Mullen Creek layered complex.



Colloform volcanogenic massive sulfide consisting of pyrite mantled by
chalcopyrite in a magnetite matrix discovered by Conoco Minerals in 1979
and quickly and quietly withdrew from public land by the US Forest 
Service. This is similar to the United Verde massive sulfide deposit.

But there are still some good gold deposits that need to be investigated further (until the goverment takes these also). Take for instance the Oregon Buttes- Dickie Springs 28.5 million ounce Tertiary paleoplacer at the base of the South Pass greenstone belt. Where did all of that gold come from? Well, Hecla showed anomalies right under the northern edge paleoplacer that were likely the source of the gold - why isn't anyone looking for this?  Then there is the question of the Seminoe Mountains-Miracle Mile gold-diamond paleoplacer along the northern edge of the Seminoe Mountains. What is there? Where did all of the gold and diamond stability minerals come from?

Stockworks in Copper King granodiorite

How about the Copper King gold deposit near Cheyenne? I like this one and have for many years and its the reason why I spent time looking at the hydrothermal alteration characteristics. Over the years, I was able to get companies to look at the property - it is a deeply eroded root zone of a porphyry gold-copper deposit that now has about 2 million gold-equivalent ounces. This property has possibilities all around it. I found evidence of hydrothermal alteration all around this deposit and mapped a fault zone along the eastern edge that offset the ore deposit, with a block down dropped on the east flank - so there is likely more gold in that block. And what is at depth? Some of the porphyry deposits in Arizona have very high grade deposits hidden at depth. Then there are similar anomalies identified by

Klein (1974) and myself.

Looking for gold - the author in 2012 searching for the mother lode

Then how about the Kurtz-Chatterton gold-copper-silver deposit and the Ferris Haggerty copper-gold-silver deposit? And the list goes on.

MAJOR GOLD DISCOVERY in CENTRAL WYOMING

Goat Mountain alkalic plug intrudes greenstone belt rocks
in the Rattlesnake Hills.

The Rattlesnake Hills gold district in central Wyoming is likely to become one of the more significant gold districts outside of Nevada and Alaska. Our new gold bookdiscusses this and other interesting gold deposits.

Gold Discovered in the Rattlesnake Hills, Central Wyoming

In 1981, an application was made to the University of Wyoming MMRRI research center for grant funds at their request. UW Engineering was looking to build a new institute to conduct research on in situ and/or bulk minable mineral deposits. Thus at their request, a grant proposal was made to investigate the Rattlesnake Hills (RSH) in central Wyoming for bulk-minable gold deposits (Hausel and Jones, 1982 a,b). The geology of the RSH appeared to be very favorable for bulk-minable gold mineralization due the the presence of a large Archean greenstone belt intruded by more than 42 alkalic plugs. The area had been investigated for the petrology of the alkalic plug by Pekarek (1977) without any regard to potential mineralization. The belt had an excellent source bed for gold (greenstone belt rocks) and several heat engines necessary to mobilize gold from the greenstone belt (alkalic intrusives) and the Tertiary intrusives potentially provided brecciation and permeability of the intruded rocks.

Thus, in 1982 several significant gold anomalies were discovered in the RSH of central Wyoming during the initial search for disseminated gold mineralization. The access route from the north was so difficult, that the muffler for the State field vehicle was ripped off of the vehicle. In honor of the muffler, the first gold discovery in this complex was named 'Lost Muffler' by Hausel. A grant was provided by the University of Wyoming Mining and Mineral Resource & Research Institute. Based on what was known of the geology at that time, it was predicted that the RSH had high potential for discovery of disseminated gold mineralization & by Hausel and Jones (1982a). In addition to disseminated gold, high-grade gold mineralization was detected in veins and exhalites (Hausel and Jones, 1982b) and gold was also detected in banded iron formation and in a large stockworks in gneiss. The RSH was interpreted as a fragment of a greenstone belt (Hausel, 1996).

Gold Discoveries

This was one of the great discoveries in North America. Gold was predicted in this belt in 1981 and verified in 1982. This was followed by several research studies - all that lead to additional gold discoveries by Hausel at the Wyoming Geological Survey. In addition, other gold anomalies were discovered by John Ray of American Copper and Nickel Company. It was a completely new discovery and unfortunate that others who entered this district more than 20+ years after the initial discoveries have attempted to take credit for discoveries that are well documented in more than a dozen publications and in press releases. But this is a sign of the times.

In 1977, Hausel was employed by the Geological Survey of Wyoming (as it was known at that time) to investigate mineral deposits in Wyoming. His first project was to investigate the Colorado-Wyoming State Line district for diamondiferous kimberlite. A group of kimberlites had been found by Eggler (1968) and McCallum and Mabarak (1975). Hausel's assignment was to produce a geological map to promote Wyoming’s resources by attracting a diamond company to test for commercial mineralization and he was hired by Dr. Daniel N. Miller Jr, director of the WGS.

During mapping, a group of 9 kimberlites were discovered that had been missed by previous investigations (Hausel and others 1979, 1981). Over the years, >600 similar diamond and kimberlite discoveries were made, most remain untested.

After the first couple of years of focusing on diamonds, Hausel began to look for other mineral deposits and made several hundred gold, silver, platinum-group, base metal and gemstone discoveries. News of these discoveries were published in local newspapers, on the Internet, in books, Wyoming Geological Association newsletters and Guidebooks and in annual reports of the State Geologist and US Bureau of Mines.

Discovery of a Major New Gold District

In 1981, a search for gold the RSH west of Casper began. Based on what was known of the geology, this area had great potential for discovery of low-grade disseminated gold & high-grade gold. Initial research was funded by a grant from the University of Wyoming MMRRI (now defunct) to search for bulk minable gold so that the university could search for a large grant to develop metallurgical recovery systems (Hausel and Jones, 1982a).

In 1977, there was no pragmatic interest in the RSH and only limited academic interest. Pekerek (1977) successfully defended a dissertation on the igneous petrology of Tertiary alkalic rocks; this followed an earlier study by Carey (1954, 1959). Both focused on the genesis of the igneous rocks, but the older Precambrian rocks remained unmapped and unexplored.

Auriferous vein in front of Goat Mountain.

Why should this region contain gold? The basement complex (Precambrian) was similar to South Pass & had been disrupted by several volcanic eruptions. Such Precambrian complexes often have rocks with above normal gold content. They are referred to as greenstone belts and in many places in the world, the terms ‘greenstone belt’ and ‘gold belt’ are essentially synonymous.

So here was an excellent source bed for gold that was intruded by high-temperature heat engines (Tertiary alkalic igneous rocks) that provided heat & fluids to leach gold from Precambrian rocks and focus the precious metals in fractures and replace select minerals in the host rocks.

Thus, armed with these concepts in 1982, field research began. However, the State of Wyoming assay budget was only about $100, thus sampling was selective. Even so, a whole new gold district was identified during this and subsequent investigations - something that rarely happens. The samples assayed yielded as much as 0.25 opt gold and the Lost Muffler vein as exposed on the surface was traced over a strike length of 2.5 miles. In addition to the samples collected in the RSH, a few samples were assayed from the Seminoe Mountains (one assayed 2.87 opt Au) greenstone belt. Both discoveries resulted in gold rushes with dozens of companies, consultants and prospectors running to the hills.

The RSH had excellent potential for significant gold. Over several years, the greenstone belt was sampled & mapped. While mapping, gold was detected in old Archean (~3 billion years old) veins, fractures, exhalites (a vein like deposit), stockworks & in much younger Tertiary (~42 million years old) breccias & igneous rocks. American Copper & Nickel entered the district & made additional discoveries in exhalites (veins). This was followed by Canyon Resources & Newmont Gold. These companies explored breccias & made a million ounce gold discovery (Hausel, 1996; Hausel and others, 2000). As predicted, the RSH had high potential for discovery of a large tonnage disseminated gold deposit associated with Tertiary volcanics (Hausel and Jones, 1982a). More recently, Evolving Gold initiated exploration in 21st century at what was initially named Sandy Mountain (their North Stock) (Hausel, 1996) & intersected major auriferous zones at depth between Sandy Mountain and Oshihan Hill where a large brittle breccia had been mapped by Hausel (1996).

It became apparent that the basement rocks in the RSH represented a fragment of an Archean greenstone belt similar to South Pass and to other rich gold districts in Australia, Africa and Canada (Hausel, 1994, 1995, 1996). The RSH belt continues under Tertiary sediments to the south, east & west. And a large part of the belt is missing. Based on geology, this fragment sits under Tertiary & Paleozoic cover to the north. How much of the belt remains hidden is unknown, but the geology indicates what is hidden is larger than that exposed – so yes, there are likely undiscovered hidden gold deposits in the RSH!

During mapping and sampling of the RSH, gold anomalies were found at several locations (Hausel, 1982, 1989, 1994, 1995, 1996, 1997; Hausel and Jones, 1982a, b). In addition to the Lost Muffler vein, another 4500-foot zone jasperized breccia vein was mapped that was weakly anomalous in gold with sporadic enriched zones. Nearby, iron formation also contained anomalous gold.

A stockwork along the southwestern margin of the RSH was anomalous. This, the breccias and Tertiary plugs at Sandy Mountain & Oshihan Hill were considered significant (Hausel, 1995, 1996; Hausel, personal field notes 1981-1995). Several grab & composite chip samples of brecciated metamorphic rock in the Antelope basin, at Sandy Mountain and at Oshihan Hill contained gold. These were collected over a surface area of one-square-mile suggesting a sizable, disseminated gold deposit!

In the vicinity of 3 Tertiary alkalic plugs (see map below) - Goat Mountain, Sandy Mountain, and Oshihan Hill, the country rock is brecciated & locally gossaniferous supporting the presence of disseminated and replacement gold – which was the original intent of the University of Wyoming grant.

During past drilling in this area by Canyon Resources and Newmont in the 1990s, a large disseminated gold deposit averaging 0.042 opt Au was identified. It is possible that Newmont identified a gold resource of >1 million ounces (Hausel and others, 2000).

But what is exciting is that Evolving Gold intersected a rich gold anomaly at depth. This area mapped by Hausel (1994, 1995, 1996) occurs along the flanks of Sandy Mountain & Oshihan Hill in a low lying area that was recently named Antelope basin. According to Evolving Gold, a high-grade 215-ft thick zone was intersected in a drill hole along the south flank of Sandy Mountain.

Drilling

Recent drilling by Evolving Gold intersected a large auriferous ore body in sections 24 and 25, T 32N, R88W. This area, mapped by Hausel (1994, 1995, 1996) along the flanks of Sandy Mountain (north stock) & Oshinan Hill (south stock) is significant.Geology. According to Evolving Gold, their targets in this area include the following: (1) Alkalic gold system with potential for a multi-million ounce gold deposit, (2) Multiple porphyry targets, including southeast porphyry zone, (3) Mineralized porphyry dikes – 30.5m at 1.89 gpt Au, including 15.2m at 3.11 gpt Au, (4) Deep stockwork mineralization with grades to 8.2 gpt Au.

The following drill results are reported by Evolving Gold:

North Stock Zone (Sandy Mountain)

RSC-003 146.3 meters @ 2.92 gpt Au

RSC-020 67.1 meters @ 10.80 gpt Au

RSC-089 158.5 meters @ 2.64 gpt A

Geological map of the Rattlesnake Hills gold district (by Hausel, 1996).

Antelope Basin (Breccia between Sandy Mountain and Oshihan Hill):

RSC-019 163.1 meters @ 1.25 gpt Au

RSC-042 76.2 meters @ 1.70 gpt Au

RSC-078 76.2 meters @ 1.77 gpt Au

Gold Porphyry Target

RSC-006 14.3 meters @ 2.21 gpt Au

RSC-027 35.1 meters @ 1.74 gpt Au

RSC-027 30.5 meters @ 1.89 gpt Au

RSC-020 lies 464 ft southwest of drill hole RSC-007. RSC-007 was drilled along the eastern flank of Sandy Mountain. RSC-020 intersected a mineralized zone that was 120-ft thick.

At RSC-007, 464 ft to the northeast, 430 ft of mineralized rock was intersected. At RSC-003 located 670 ft north of RSC-007, 480 ft of mineralization was intersected.

Breccia found at Sandy Mountain during mapping project by Hausel.

Drilling to date has identified a mineralized body that has a 1440 ft strike length that is 640 ft wide and 1760 ft deep. The average grade of mineralized zones are 0.03 opt Au. The data supports a central high grade mineralized zone surrounded by a low grade gold halo producing a large tonnage gold deposit that will likely be minable by open pit and underground mining.

So will there be a gold mine in the RSH? In 1981 & 1982, this greenstone belt was considered to have high potential for commercial gold deposits. RSH also has the added attraction of disrupted zones associated with Tertiary intrusives. The area is located in the middle of nowhere with no active streams & no population to speak of.

However, there is an old saying in the mining industry - "mines are not found, they are made". Whether Evolving Gold can make a mine out if this property remains to be seen. There are many factors involved in any company and its investors and the involvement of government interference and environmental groups who look to stop all human progress. EV has a good property that was considered highly prospective >25 years ago. If they can make a mine out of this property, it will result in other gold mines in Wyoming. Problems seen by the industry with Wyoming has been its reputation for gothic politics that is only comparable to Louisiana and an incorrect perception that the state is poorly mineralized. Even so, the latter has been proven wrong (Hausel, 1989, 1997, 1998, 2000, 2009; Hausel and Sutherland, 2000).

Drill data by EV supports a central high grade mineralized zone surrounded by a low grade gold halo in a large tonnage gold deposit. This is a significant deposit that was initially mapped by Hausel as a large breccia zone nearly a mile long! This discovery will result in increased activity in Wyoming and notable increases in Mineral Hill, Black Butte, Bear Lodge Mountains, South Pass, Seminoe Mountains, Granite Mountains & Sierra Madre in Wyoming as well as in the Tobacco Root and other supracrustal terrains in Montana.

Granite Mountains

The RSH are part of the Granite Mountains. The Granite Mountains are actually hills and probably should be called the Granite Hills. These hills form a belt of Archean rocks immersed in a sea of Cenozoic sediments. The Precambrian terrain is divided into two general units: (1) a complex belt of amphibolite-grade metamorphic rocks exposed along the northwestern and northern margins of the Granite Mountains at Tin Cup and the Rattlesnake Hills-Barlow Gap areas, & (2) 2.6 Ga (billion year old) granites in the center of the uplift. These are intruded by later tholeiitic dikes that cut the granite & metamorphic rocks (Stuckless and Peterman, 1977). Along the northern edge of the hills, Tertiary (40 to 44 Ma – million year old) alkalic phonolites & latites cut the Precambrian rocks (Pekerek, 1977).

The schists in the hills are metavolcanic schists and gneisses that were metamorphosed to amphibolite grade at 2.9 Ga. However, Sr87/Sr86 ratios are unusually high for rocks of this age. To explain such high ratios, these rocks likely formed as much as 3.2 to 3.3 Ga ago (Peterman and Hildreth, 1978).

The metamorphics have steep, southerly dipping, northeasterly to easterly foliation trends (Hausel, 1995, 1996). These include quartzofeldspathic gneiss, augen gneiss, epidote gneiss, biotite gneiss, metagreywacke, amphibolite, metabasalt, minor serpentinite & banded iron formation (Peterman and Hildreth, 1978; Hausel, 1996). At Barlow Gap, both oxide- and silicate-facies BIF are reported (Bickford, 1977). In the Tin Cup belt, massive sulfides are found in hematitic iron formation along with scattered copper, gold & iron anomalies & exotic ornamental stones & gemstones including agates, jade, sapphires & rubies (Love, 1970; Hausel and Sutherland, 2000; Hausel, 2009). Diamonds were also reportedly found in this area by a prospector from Laramie - Eugene Clark.

Summary

The RSH is a newly discovered gold district that remained overlooked until several gold discoveries were made in 1982. This was followed by additional discoveries from 1982 to 1995 (Hausel, 1996) along with discoveries made by John Ray of ACNC. In the 21st century, Evolving Gold and others entered the district and interested gold anomalies by drilling, more than 20 years after initial gold discoveries made by Hausel and Ray in the 1980s. With an assay budget of $100/year, the Wyoming Geological Survey was unable to drill, but predicted where gold would be found and verified the presence of anomalous gold with a very minimal assay budget. It is very exciting to see the extraordinary gold intercepts from recent drilling in the area proposed by Hausel as a bulk minable target in 1982. The exploration and work that has been conducted by Evolving Gold in recent years is extraordinary and we are all hoping to see Wyoming's first gold mine in nearly a century.

Gold and Gossan

Gold and Gossan

Gold in the San Juan Mountains of Colorado. As a gold prospector you should immediately notice the mine dumps, lack of trees growing on the yellow, brown, reddish brown and tawny colored rock and soil known as gossan. It's obvious that these gossans were mined in the past, but look at all of the exposed gossan in the high peaks that have not been mined. It is likely there are several rich gold and silver deposits still to be found in this area. Just search Google Earth for 'Red Mountain No. 1, Colorado', or 'Silverton, Colorado' to find this and other gossans scattered over a very large region near the 'Million Dollar Highway (550) in southwestern Colorado.

Gold Prospectors like to generalize gold deposits into two groups - lode gold (gold which is found in place in outcrop) and placer gold(detrital gold eroded from a nearby lode and deposited in a stream). Both deposits are important, but for the gold prospector, placer gold deposits are most important because many can be worked with smaller resources and less cost that most lode gold deposits. But still, you need to consider scientific prospecting methods to insure that you have a commercial gold deposit and that you do not make mistakes like many of us have seen on the TV program Gold Rush.

This morning, I'm going to talk a little about gossans - something every gold prospector needs to know about as these are often guides to lode gold, and they are constantly overlooked by gold prospectors. They are also guides to placer gold simply because if they are gold bearing, erosion will tend to release the gold over time and transport the precious metal down slope to a nearby stream. As an example, while watchingGold Rush, I keep seeing a distinct gossan each week located at one of the featured deposits, and it is never mentioned on the program by anyone, nor is it ever explored. So after you learn about gossans, start looking for these on Gold Rush, but also look for gossans on sites like Google Earth.


Pyrite cubes in chlorite groundmass. Note not only the pyrite, but also the
 cubic pits where other crystals of 'fool's gold' fell out of the rock.

And how important are gossans? Over the years, I identified several hundred gold anomalies and several gold deposits, most are associated with some kind of gossan. I've been so successful with this that I have found nearly $100 billion in gold contained in gold deposits! For example, check out the following sites at the University of Wyoming, the Casper Journal,Planet News, and the Gemstone State. After reading these, you probably have a picture of me in a jacked-up, 4-wheel drive Ferrari with oversized mud tires prospecting for gold in the outback. Well, I've been blessed with excellent prospecting intuition, but when it comes to retaining treasure - I must have been absent when they passed out that part of the brains. So yes, I've made many people very rich, but I'm not one of them. No problem: if I had to do it over again, I would have done it all pretty much the same. I do wish I had some of that money to pass it on to my kids and grandkids, but I love to prospect and material possessions are not that important to me.



One, large, massive piece of pyrite (fools gold) showing it's cubic crystal
habit. This specimen has relatively high heft.

Oops, I forgot: I was talking about gossans. Most of us are familiar with pyrite (FeS₂), an iron-sulfide mineral that we often hear discribed as 'fool's gold'. It should be called'doublely fool's gold' because you can be fooled by it two different ways. First, it's not gold, although it kind of looks like gold to the uninitiated.



Gold from Douglas Creek, Wyoming. Note the distinct warm yellow color of
gold as compared to the brassy color of pyrite. Also the gold is
characteristically rounded and much heavier than pyrite.

In mymineralogy book, I described pyrite as having relatively high heft. This means it has a relatively high specific gravity (5.0) such that if you had one, big, massive piece of pyrite with no rock matrix, it would feel heavy. If you hefted it up into the air and caught it in your hand, the specific gravity would be noticably high. Pyrite has a specific gravity of 5.0, meaning it is 5 times as heavy as an equivalent volume of water. I also point out that pyrite is brassy colored, not gold colored. other things of note mentioned in my book is that pyrite is brittle, whereas gold is maleable. This means if you apply pressure to pyrite, it will crush to a fine greenish-black powder, but gold will just deform. So, don't make the mistake of thinking pyrite is gold - it can be costly in some cases.

But as a gold prospector, you need to also realize that pyrite can fool you again - particularly if you throw it away without assaying it. In my2011 gold book co-authored my son, we describe some pyrite around the world that has considerable hidden gold! That's right, as much as 2000 ppm (parts per million) gold has been noted hidden inside the pyrite crystals. That means as much as 60 ounces of gold per tonnemight be hidden right under your nose and you may never see it if you don't have it assayed, crush the pyrite to a very fine powder and pan it for gold, examine many specimens under a microscope, or look closely at the gossan produced by the pyrite for visible gold. But one more way it can actually fool you is that you may have a good gold deposit in what is known as noseeum gold (invisible gold). Well, the gold is not really invisible except to our eyes. It is in stealth mode with individual gold atoms replacing some of the iron atoms in the pyrite atomic structure. So how do you know its there and how do you get it?

In this case, it has to be assayed. Then to recover it requires some serious chemistry mentioned in our gold book. If you have a lot of invisible gold, it might be in your best interest to try to sell it to a mining company as it is not going to be cheap to mine and recover.

United Verde mine, Jerome, Arizona. Note the well-defined gossan exposed in the highwall. This mine was so rich in pyrite, that the pyrite actually caught on fire deep underground and burned for many years.

Back to gossan. Pyrite is just iron sulfide. When it weathers, it produces a chemical reaction that releases heat yielding sulfuric acid (H₂SO₄), rotten egg gas (Fe₂S) and rust (Fe₂0₃, Fe0H). If you have ever been close to any politician, you have a good idea of what hydrogen-sulfide(rotten egg gas) smells like. If pyrite is massive enough and suddenly comes in contact with oxygen, it can actually catch on fire because of heat released by the chemical reaction to produce rust. This actually happened at the United Verde mine in Arizona, where miners interesected massive sulfides (pyrite) at depth exposing the sulfides to oxygen: the fire burned underground for many years until it extinguished itself.



Sample of  massive pyrite collected from the Tin Cup district. Note that the brassy, metallic pyrite appears to be partially replaced by brownish mud. The brown material is actuallylimonite, goethite and hematite (rust) or the classical gossan!

So, pyrite tends to rust and is replaced slowly by limonite, hematite and goethite (iron oxides). So by now, you should start getting an idea of what a gossan is. It is rust produced from sulfide minerals that sometimes contain gold and silver. So this is why we look for gossans.

Gold in rusty gossan from the Mary Ellen Mine, South Pass district. All of
the brown material was originally pyrite that rusted to limonite and goethite
while exposiing the gold hidden inside the pyrite.

Now if the pyrite has gold, the gold is most often immobile (which means it remains right were it originated while the pyrite (chalcopyrite, chalcocite, etc) turns to rust. Often, this results in visible gold showing up in the gossan.

A few months ago, someone contacted me and sent an excellent photo of a piece of limonite with quartz and lots of visible gold. This photo is perfect to illustrate what I'm writing about, but I need to dig through my email and get this person's permission and name to give them credit. Hopefully, I can find that email - if not, please send me your gold photos (with limonite), name and permission to use. Until I get permission from that person, the photo above also works quite well. This is a specimen found in the Mary Ellen mine by Steve Gyorvary who donated it to the Wyoming Geological Survey (before it became a den of scum from 2004-2008) and I photographed it using a binocular microscope (the scale is not really in meters as I like to tell some people, it is a millimeter scale).

Chalcopyrite (also known as copper pyrite) also will rust to produce gossan with some copper minerals such as tenorite, cuprite, malachite, etc.

So, if you have a lot of pyrite and it rusts, you now have a gossan and an excellent visible guide to gold, silver and other valuable materials. Sometimes pyrite will oxidize and leave silica rich ridges that look porus that are known as boxworks. When you find boxworks, always look close at the ridges to see if there is any visible gold.



Limonite boxworks after pyrite. Note the distinct porous appearance of this
sample - the pores are often good places to look for visible gold. Such samples
from Arizona, Alaska, California, Montana, Nevada, Colorado, Utah,
Idaho, Oregon, Washington and Wyoming often have visible gold.

In 1981, I started one of several gold rushes in Wyoming after finding specimens of gossan and boxworks with visible gold. The samples assayed as high as 2.87 ounces per ton of gold! These were found on the Penn mine dumps in the Seminoe Mountains greenstone belt.

Pyrite and chalcopyrite not only produce gossans, but other valuable minerals also produce gossans. Often the gossans will have slighting different colors due to trace metals.

Beautiful fluorite producing a distinct yellow limonite. Fluroite is sometimes found with gold. This specimen from the Bear Lodge Mountains district where some gold and rare earth deposits are found.

Arsenopyrite with blood reddish brown limonite gossan. Arsenopyrite smells like garlic (its the arsenic) and sometimes yields a greenish-yellow limonite. Often arsenopyrite also contains hidden gold as we discovered in Alaska.
 

Garimpo marcou história de Itaituba

Garimpo marcou história de Itaituba

"Coméricio de ouro representa mais da metade da economia da cidade"

Imagem ilustrativa

A diversidade do Vale do Rio Tapajós foi um dos grandes responsáveis pela ocupação de Itaituba, que hoje ostenta títulos como Cidade Pepita e Província Mineral. A história de cada morador do município tem uma passagem pelo garimpo, algumas bem-sucedidas, outras nem tanto. Maria de Lourdes Linhares da Silva viveu as duas experiências.

Ainda mocinha, deixou o Maranhão rumo a Itaituba para trabalhar no garimpo, onde o irmão já estava há algum tempo. Não tinha ideia do que era uma mina de extração de ouro. Ao chegar no local, foi encaminhada para uma casa de prostituição. Por sorte, foi resgatada pelo irmão, que queria enviá-la de volta para o Maranhão. 

Mas Maria de Lourdes bateu o pé e encontrou uma forma de ganhar dinheiro: cozinhava, lavava e passava para os garimpeiros. Em troca recebia ouro. “Juntei 150 gramas (de ouro), fui para Manaus, comprei várias mercadorias e comecei a vender no garimpo.” Aos poucos, montou uma loja para atender os trabalhadores. “Com o dinheiro, comprei terra e casa em Itaituba”, conta ela. 

Personagens como Maria de Lourdes estão espalhados por todos os cantos de Itaituba. Nem todos, no entanto, gostam de falar do garimpo. Muitos fizeram do ouro o trampolim para negócios mais sólidos. Viraram donos de empresas de aviões, comércio e restaurantes. Muitos garimpeiros, no entanto, continuam sem dinheiro e sem patrimônio. Reinvestiram tudo na exploração de ouro, sonhando em fazer uma fortuna que até hoje não veio. 

Imagem ilustrativa

Na cidade do ouro, as caminhonetes (nacionais e importadas) - sonho de consumo de muitos brasileiros - representam 30% dos automóveis e comerciais leves. Os moradores dizem que muitos não têm  casa própria, mas têm uma caminhonete “traçada” (com tração nas quatro rodas). Uma Hilux 2010, por exemplo, está na casa de R$ 99 mil.

Hoje a mineração e o comércio de ouro representam mais da metade da economia de Itaituba, por  onde circulam entre 400 e 800 quilos do metal por mês. “Infelizmente, uma parte vem do garimpo ilegal”, afirma o presidente da Associação Nacional do Ouro (Anore), Dirceu Frederico.