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 Wyoming

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1866 Map showing Wyoming in the upper left corner.  South Pass can be found on the Oregon Trail.

One of the most prolific areas for finding gold in Wyoming is around the South Pass area where many gold deposits have been found over the years.  Some of these deposits are measured in the millions of ounces. The state legislature in their infinite wisdom has placed the Carissa Mine with Wyoming’s version of Disneyland so it will never be developed although there is still from $1 to $5 billion worth of potential gold reserves that could be recovered from this deposit during a time of national financial crisis. The mine could also provide hundreds of jobs. Unlike the Abitibi and other greenstone belts in Canada the area around South Pass remains largely unexplored.

Dan Hausel, a geologist has mapped hundreds of gold anomalies over the past thirty years in the South Pass area. The area is a granite-greenstone belt where Hausel mapped over 450 square miles in five field seasons while he was living in a tent. Significant potential is there for iron and gold deposits as well as the possibility of finding colored gems as in the past the area has already produced specimens of aquamarine and diamond.   After bringing fame to the Wyoming Geological Survey Dan retired in 2007, and moved to Arizona.

Oregon Buttes is another area having a huge potential in both paleo-placers and conventional placers.  Geologists consider the buttes to be one of the largest deposits of gold in North America.  The source of all this gold is unknown, but is presumed to be from the South Pass deposits where it was eroded and later deposited at the buttes.

A gold nugget from Williams Creek Wyoming

Photo by Rob Lavinsky

In 1870 the army established Camp Stambaugh near Atlantic City to protect the miners from the Indians, but many of the soldiers deserted to hunt for gold in the area. By 1872 there were twelve stamp mills operation in the area although hostilities drove the miners from the South Pass area until 1882 with the signing of the Treaty of Five Nations. The South Pass area holds many significant hidden and visible gold structures located in a shear zone with the Carissa Mine being the richest.  This is an intensely deformed zone of iron oxides where the primary shear zone ranges from 1.5 to 80 feet wide. The deposit at Carissa is similar in many respects to the Homestake mine in Lead, South Dakota.  There is plenty of geological evidence this shear zone extends to great depths under the Carissa mine. 

Gold was first discovered in Wyoming in 1842 by one of the mountain men working for the American Fur Company, but it wasn’t until 1855 when gold mining started in 1855 when a group of gold miners came to South Pass from the goldfields of California,  Later in 1861 another group of miners commenced mining the placer deposits along Willow Creek. The next discovery was in 1863 when another group of miners discovered the placer gold deposits at the Oregon Buttes.

According to the United States Geological Survey (USGS) Oregon Buttes comprises one of the largest undeveloped gold deposits in the United States.  The gold at the buttes is thought to have its origin in the greenstone belts found at South Pass.

Western Wyoming contains most of the gold deposits in the state although it is likely that some gold can be found in northeastern Wyoming where it joins the Black Hills of South Dakota.

Gold isn’t the only treasure Wyoming holds, some of the finest jade in the world is also found in Wyoming.  The jade occasionally has specks of gold imbedded in the jade making a beautiful specimen.