Jade and Gold

A piece of uncut jade
photo by Immanuel Giel

According to John Sinkankas (1959) there is one small deposit of jade found in an undisclosed location in California that exhibits small flecks of gold making it a rarity.  Too say the least your author has seen one polished example of this jade, and it is quite handsome being green with specks of gold throughout. 

California contains both jadeite and nephrite two distinct minerals with jadeite being a pyroxene mineral while nephrite is an amphibole intermediate between actinolite and tremolite.  They are both found in a high pressure/low temperature environment like that found in the coastal ranges of California. 

This geological environment is considered by many geologists to be blue schist facies.  One area near Monterrey called Jade Cove is a place where many large boulders of jade have been found in the Pacific Ocean.  These boulders are usually found covered with a tannish crust caused by weathering.  The true nature of these boulders is not seen until this crust is broken through.

A nephrite desk set by Faberage
Photo by Shakko

Jadeite is a member of the pyroxene group of minerals with a composition of sodium aluminum silicate (NaAlSi₂O₆).  This variety of jade is found in California and other places in the world.  The most precious form of jade called Imperial Jade by the Chinese comes from Burma.  Jadeite deposits are relatively rare.

Nephrite jade sometimes called Wyoming Jade the state gemstone was first found in the Granite Mountains in central Wyoming with the most intensive exploration taking place from 1940 through 1960, but recent activity in the jade producing areas indicate a new interest in this gem.  Most of the high-grade nephrite jade has been found in alluvial deposits in and around the Granite Mountains in central Wyoming.

A Mayan facemask made from jadeite

Other large scale deposits of this mineral are also found in Alaska and British Colombia the finest jade in the world however is that found in Wyoming.

Nephrite is calcium magnesium silicate [Ca2(Fe, Mg) 5Si₈O₂₂(OH)₂. some of the nephrite found in Wyoming is colored emerald green by chromium atoms entrapped in its crystalline structure,  The normal green is caused by iron atoms and black nephrite is caused by an excess of iron.  When iron is absent the color is colorless, but appears cloudy white because of its fibrous structure.

Nephrite containing specks of gold is rare so far only known from one locality in California.  Further investigation will eventually locate further localities.

Gold Occurrences in British Columbia

It is near Mt. Robeson where the Fraser River rises that was the scene of a gold rush in 1859.   Tobi87

It was in Yale, British Columbia on the banks of the Fraser River where I first learned about British Columbia gold there were several flour sized flakes gold in the bottom of my gold pan. From what I understand this flour sized gold is characteristic of the Fraser River. For the benefit of the reading audience it takes approximately 40,000 of these to weigh a troy ounce (31.1 g).  At the time there was a terrific thunder shower coming up, and I worked the pan out in about two minutes leaving the proprietor of the gold panning site completely mystified because he had already seen the Connecticut greenhorn could work so fast, he already seen the plates on my car.  He didn't know I had been a prospector most of my life. The Fraser River was the site of a gold rush in 1859, and there is still gold to be found in the Fraser River system.  There are also jade boulders found with the gold in the river.

Yale, British Columbia during the Freaser River Gold Rush in 1859

British Columbia also contains the southern terminus of the Tintina Gold Belt in the northern part of the province. This appears to be the largest gold belt in the world since it is traceable all the way from northern British Columbia, through the southwest corner of the Yukon Territory and sweeping all the way across Alaska for a distance of 1200 km where it finally ends in the Pacific Ocean just above Anchorage, Alaska.

The first discovery of gold by Whiteman was at Gold Harbor on the west coast of Moresby Island near the Haida village of Tasa in 1850 where it was discovered on Mitchell Inlet, an arm of Gold Harbor.  This discovery touched off a brief gold rush in 1851.  This led to the area being declared the Colony of the Queen Charlotte Islands.  The British government didn’t want the islands to be overrun by American Miners even though the gold deposits proved to be superficial in nature, and there are stories about the American miners being harassed by the local Haida warriors.  Later the area became the site of a modern mine for iron rather then gold.

Like all the beaches in the Pacific Northwest of the United States and Canada The beaches do contain flour gold in payable amounts sometimes covering the beaches with enough gold so they attract the locals trying to get as much of this gold as possible before the next tide washes it away until the next big storm that may wash up enough gold to be noticeable again.  In the same area the mountains of the coastal range including the British Columbia Batholith have had several producing gold mines and numerous showings of gold.

There is another gold producing area on the western slopes of the Rockies and the rivers and streams draining them.  This area was made famous during the Fraser River Gold Rush and the later Caribou Gold Rush. 

Gold is not the only source of mineral wealth in the province because it also contains world class deposits of jade that are mined both in-situ and as boulders of jade found in numerous rivers.  The area around Cache Creek has produced both gold and jade.  British Columbia is also noted for producing large quantities of copper, lead and silver.

British Columbia has vast deposits of mineral wealth throughout its length and breadth with many deposits yet to be discovered.  There are numerous mines that are accessible only by air especially in the northern part of the province.

A simple test for gold

Hydrochloric acid is sometimes called muriatic acid when it is in dilute form.  The dilute acid can be used as a simple test for gold.

Sometimes it is a case of not being able to see the forest for the trees, and sometimes I am guilty of this fault among the many others I have. Gold is not called the noble metal because it is used to make crowns, but because there are very few things that can cause it to dissolve. Aqua regia, a mixture of one part of nitric acid and three parts of hydrochloric acid is one of them. It can also be dissolved in a solution sodium cyanide, and a few other compounds.

There are very few minerals that resemble gold alone and a few sulfides that are commonly called fools gold. Some weathered mica can also resemble gold if these substances are treated with acid they will dissolve and emit an odor like rotten eggs. You can use ordinary vinegar to make this test if you want, but muriatic acid works even better. You can buy this acid at a local mason supply store or some times at your local hardware store. Another source of acid can be found in your local auto parts store under the name “battery acid.” Battery acid is a dilute form of sulfuric acid, but any of them will work for this test.

If the material forms than crystals, and it is the color of gold is most probably fools gold. When acid is supplied to this material it will make a gas called hydrogen sulfide is smells just like rotten eggs, you can't miss it. Gold is not affected by any of these acids, nor does it create a smell. This is not to be considered a definitive test for gold, but it sure eliminates in a real hurry many things that do look like gold.

Weathered mica is one of the few things that may not eliminate, but the reaction when acid may bleach the iron staining that makes it look like gold. In any event weathered mica is about nine times lighter than real gold. The only other metals that are not affected by acid are the platinum group metals because they are also considered to be noble metals.

Gold and platinum are often found together so much so that the early Spanish Conquistadors in Peru used platinum as an alloy in their coinage because they had no value for platinum. During the 20th century many of the Spanish coins were dissolve so their platinum content could be recovered.

This test can be used on both gold that is visible to the naked eye, and gold that is only visible under a microscope. It is best to draw a circle around microscopic specimens with a pencil so you can find them again. The graphite in a pencil is not affected by any acid, but don't use a ballpoint pen because the eight may be affected by the acid.

Something else that can be added to your prospecting equipment is a dropper bottle for holding the acid allowing you to dispense it one drop at a time. For many tests all you do this a single drop of acid. This test is also useful for finding out if a stone as limestone or not. In the presence of calcium carbonate it fizzes.  It doesn't affect Quartz, but gold is often found in either mineral. Occasionally it is also found in Jade as flecks of gold.

Nancy Twinkie sees Green and finds Platinum

After a few prospecting and rock hounding trips it was apparent that Nancy Twinkie was going to become a seasoned prospector and it wasn't just for gold. On the road from Chester Massachusetts to Middlefield you drive by a long stretch of serpentinite along the road where the builders had blasted the road out of the side of a mountain. The serpentine that came off that mountain during the 19th century was used as ship’s ballast by an enterprising ship captain that originally came from Chester.

This is a piece of uncut jade that resembles the serpentine found in Chester, Massachusetts.

In a previous voyage he had taken some of the serpentine to China, and the Chinese jade carvers fell in love with the stuff because it looked just like jade and was easier to car because it was softer. For it while there was a brisk trade in the serpentine, and several shiploads found their way to China where it was carved then exported back to the United States and the rest of the Western world as Soochow jade.

Just about in the center of this exposure of serpentine a small stream came down off the mountain, and although at different times I had stopped alongside this road cut to pick up some samples of serpentine myself, and quickly discovered that it was fine cutting material for making cabochons that were greenish incolor and displayed some interesting patterns.

A platinum nugget of the same color of what we found in our gold pans.
Photo by Rob Lavinsky

On one of our rock hounding trips into the Berkshires Nancy Twinkie and me stopped at this small stream to see if it contained any gold. Because serpentine is derived from metamorphosed oceanic crust that in some places is called greenstone there was a pretty good probability that we may find some gold. We didn't, but what we did find were some very small flakes of silvery metal that although we never tested these flakes to see what they really were there is a good possibility that they were platinum. Serpentine is what they call an ultra-mafic rock in which platinum is known to occur; so there is a good possibility that was what we found that day.

Gold associated with belts and greenstone in many places in the world where they produce gold; one of these so called greenstone belts is the Abitibi gold belt in Québec and Ontario is one of the great gold producing areas on earth. You might say that Nancy Twinkie saw the greenstone, serpentine, and probably found platinum.