The beautiful blues and greens of turquoise have been treasured by many cultures all across the world since pre-historic times. Turquoise has been mined from a number of locations worldwide, including Persia (present day Iran), Tibet, China, Egypt and the southwest US. Nearly everywhere it was mined, it was highly valued by the local cultures. When turquoise was first introduced to Europe in the middle ages, the material was fine quality blue turquoise from mines located in present day Iran. However, because the material came to Europe via Turkey, it became known as the “Turkish stone”, later corrupted to its present name, turquoise.

Because labor costs are low and mining turquoise is a labor intensive process that must be done by hand, China is by far the world's largest supplier of turquoise at the present time. While most American jewelers would prefer to work with American turquoise, probably more than 80% of the stone on the U.S. market today is Chinese due to the scarcity of American turquoise. The vast majority of Chinese turquoise mined and sold here in the US is of a lower grade, and is often treated with plastic resin, oil or paraffin wax (a method much inferior to stabilization with plastic resins). This is simply a function of the geology of the formation of the Chinese deposits.

However, Chinese turquoise actually can be found in a full range of colors, grades and qualities. Because the lower grade material is the vast majority of the production, it is the cheap, low quality product that most people are familiar with. There is a gem-grade Chinese that sells for up to $1200/pound but it's rare and most people will never see it; it's set in gold right away, and sold mostly in the orient. The highest grades from a few of the Chinese mines actually display turquoise colors reminiscent of the much prized blues and greens from some of the famous mines of Nevada. When available, this gem grade material is sold by the gram in the rough, valued by the carat as finished gems. However, in general, American turquoise of equal grade commands a higher price, and in fact unscrupulous dealers sometimes sell fine Chinese material as American. It's just that there's more Chinese available, so American is more valuable (at least to us Americans). Still, fine gem grade Chinese turquoise is extremely rare and valuable. It is important to know what you are actually buying, as American turquoise jewelry should, and will, always cost more (if you can get a guarantee that it's really made from natural American material).

Most natural, untreated turquoise from the US is marketed under the name of the mine it originally came from such as Bisbee or Morenci (from Arizona), Blue Gem, Carico Lake, Royston or #8 (from Nevada). Although color and matrix does vary quite a bit at most mines, the majority of the production from most mines does have at least a generally similar appearance. Because of this, certain mines have become famous for their distinctive colors and matrix. Bisbee is known for its deep blues and smoky matrix; Stormy Mountain is known for its contrasting black matrix, Blue Gem is known for its distinctive aqua "watery" look and "glassy" stones; Sleeping Beauty is known for its consistent clear blues that can be easily matched for cluster, needlepoint, inlay and other Zuni jewelry styles. The #8 Mine in Nevada is collectible for its golden and black web spiderwebbing. Stones that exemplify these attractive qualities are collectible. So in a very general way, the mine location does serve in part to define the type of turquoise, and it also specifies that the turquoise is indeed genuine American mined gem grade material.
Most of the really famous turquoise mines are long closed and haven't produced for years, so a good question to ask is: where is the American turquoise currently on the market coming from? Although a small amount of new material continues to be mined at small operations in the western US, much comes from old stocks. When turquoise reached astronomical prices in the 1960s and 1970s, those high prices led to many mines opening and unprecedented amount of turquoise was placed on the market. When demand fell, huge stocks of rough turquoise remained on hand and unsold. The old miners had a habit of stock-piling their rough turquoise for years, preferring to hoard rather than sell it, because they knew how undervalued it was when the market collapsed. With the passing of these miners and the recent upsurge in interest in turquoise, old collections are being found and/or released by heirs or miners that are finally ready to let go of their turquoise. For the most part, the mines have remained closed although there was always some demand for gem quality turquoise. Those old stocks have been nearly all consumed and prices are beginning to move upward sharply. The mines that no longer produce are the rarest and more collectible but quality natural gem-grade turquoise jewelry from any mine is a good investment and a joy to wear.

For More general information on sources of turquoise, Check out our web page at:
http://nevada-outback-gems.com/Encyclopedia_pages/Turquoise_info.htm

For more information about Turquoise mines, Check out the author’s web page at
http://nevada-outback-gems.com/turq_info_pages/Turquoise_inf_Mines.htm

Chris Ralph writes on small scale mining and prospecting for the ICMJ Mining Journal. He has a Mining Engineering degree from the Mackay School of Mines and currently works as an Environmental Engineer. He owns 3 Nevada turquoise mines and markets his own line of jewelry. His jewelry and information site can be seen at:
http://nevada-outback-gems.com