Sources of Turquoise in the US

March 16, 2010

Copper and aluminum are the main ingredients in turquoise. This stone is generally found in areas of low precipitation and high evaporation, and typically in close proximity to copper deposits. When it was first discovered around 3000 BC, only important people in society were allowed to own it. Things have changed since then, and today a sterling silver turquoise pendant or some piece of other jewelry containing turquoise is a must for every woman’s wardrobe, especially in the Western states in the US. This article discusses turquoise mining in the United States.Arizona Arizona has several large copper deposits in turquoise can be found in close proximity to many of these locations. One of the most productive and famous turquoise mines in the US in the Bisbee mine. For many decades, the turquoise mine was operated as part of the copper mining being conducted here. This mine has produced some of the best quality turquoise in the world. The specimens are hard, bright blue, and have a well distributed pattern or fine dark veins. The mine is known to produce gem quality specimens that require no additional treatment other than cutting and polishing before use in jewelry. The other big copper deposit in Arizona – the Morenci mine – also has turquoise associated with it. The specimens here generally are aqua blue in color and contain black iron pyrites. The turquoise from Morenci takes a good shine and is some of the best in the world. Both these mines now produce only small amounts of turquoise. The Sleeping Beauty mine near Globe is the largest operating turquoise mine in the US. The characteristic of turquoise from this mine is that it has little if any vein pattern. For many years, the turquoise mine in Kingman was famous for its high quality stones. There is no production at the Kingman mine today.

Nevada The Royston area in Nevada has a few operating mines. Of these, the Ajax mine is perhaps the smallest and the most recent. The specimens from this mine are blue, or a combination of blue and green. The unusual color of the specimens from this mine has raised interest in this prospect. Turquoise from the Damali mine sometimes contains zinc. The presence of zinc causes the stone to be yellow in color, and also makes it harder than most other turquoise. The Dry Creek mine in Nevada is also worthy of mention. The turquoise here contains a relatively high amount of aluminum. So the specimens from this mine are light blue, and sometimes have no blue coloration at all. The turquoise found in Esmeralda County is generally in the form of nodules. The stones range in color from solid blue, to blue with the characteristic spider webbing.New Mexico The Cerrillos mine in New Mexico deserves special mention. The first turquoise mining operations were carried out here, about 10 miles from Santa Fe. The color of the stone has ranged from khaki green to a brilliant bluish green. The specimens from this mine are generally very hard and can be polished to a high shine. Production from this mine today is quite low. For many years, the Tyronne mine near Silver City was known for its turquoise production. However, a change in the copper mining process here has put an end to turquoise mining here.