Birthstones & Gemstones: Peridot of the American Southwest
If your birthstone is peridot, you might think it is an exotic stone from a distant land of tropical rains. And while some peridot does come from travel-poster places, one of the largest deposits of peridot is in the US.
It comes from a desert mesa on the San Carlos Apache Reservation in Arizona.
At Right: This is a beautifully cut yellow-green peridot set in white gold. Photo courtesy of Joseph Jewelry, Bellevue, Washington.
Although there are no records kept of the production, it’s estimated that the 90-meter high Peridot Mesa produces thousands of carats of the gemstone each year. They’re hard-won carats, too. Almost all the mining is done in open pits. The stones are hacked out of the hard basalt by hand, with hammers and chisels, picks, shovels, and rakes. Only rarely is blasting done as it can shatter the somewhat brittle peridot crystals.
They’re a treat for gemologists because besides containing the usual peridot “lily pad” inclusions, they hold bits of natural glass which themselves contain gas bubbles. They also have what inclusionologist John I. Koivula has described as “smoke-like veils” — though the image in his article about San Carlos peridot looks more like kelp floating underwater. A good microscope and you may not come up for hours.
The Apache residents have the only rights to work the area which is entirely on tribal land. Miners usually work alone or with their families, selling the day’s find to local buyers.
Most crystals are small, and the finished goods range in size between 0.5 ct to 3 carats. Sizes over 5 carats are extremely rare. But the color is a fine yellow green. That and the fact that they are domestic stones makes them worth seeking out at gem shows or from trading posts in the area or the Apache Cultural Center in San Carlos.
For images of the mining and samples of the rough and finished peridot, see “San Carlos Peridot,” by John I. Koivula in the Winter 1981 issue of Gems & Gemology.
Be sure to read all the other posts in this 5 part series:
Peridot — Just the Facts
Sharon Elaine Thompson is a GG and FGA who has been writing on gemstone and jewelry topics for Lapidary Journal Jewelry Artist since 1987. She also writes a line of Birthstone Romances under the name Liz Hartley.
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