Figure 7.--Peridot from the San Carlos Apache reservation in Arizona.
(Photo is courtesy of ICA/Bart Curren.)
Peridot is the best known gem variety of olivine, a species name for a series of magnesium-iron rich silicate minerals. This bright yellow-green to green gemstone has caught the fancy of humans for thousands of years. Some historians even suspect that at least some of the "emeralds" worn by Cleopatra were actually peridot. Much of its recent popularity can be explained by its currently being recognized as the birthstone for the month of August, people wear the stone because it is supposed to bring the wearer success, peace, and good luck.
The United States was for many years the largest producer of peridot, the value of production in 1993 was estimated to be about $1.5 million, according to the USBM. The United States is getting major Competition from China and Pakistan for the title of world's largest producer.
The earliest recorded production of peridot was in about 70 A.D. from St. Johns Island in the Red Sea, about 54 kilometers off the coast of Egypt. Most of the earliest known peridot gems came from this location and small amounts of material are still being produced from there today. Later, very large, fine-quality peridot was produced from deposits in Myanmar (formerly Burma). These deposits were well known for their 20- to 40-carat cut stones of superb color and clarity, but since the socialist government came to power, the supply of Burmese peridot has been curtailed to such a point as to no longer be a factor in the industry. One can only guess as to whether the deposits are mined out, or if government policies have resulted in the shortage of material.
Arizona.--Currently, the United States is the basic supplier of peridot to the world gemstone industry. Deposits in Arizona are the major source of U.S. peridot. Faceted Arizona peridot is highly prized locally, but also enjoys widespread popularity for the manufacture of birthstone and other jewelry. The bright green, yellow-green to olive-green peridot is used both as a faceted and tumbled gem. The faceted stones are used in rings, earrings, pendants, bracelets, and as accent stones. The tumbled gems can be set in baroque jewelry, drilled and strung as beads, used in mosaics, and in the manufacture of gem trees.
Peridot Mesa, located on the San Carlos Apache Indian Reservation east of Globe in Gila County, is the most productive locality for peridot in the world. A second Arizona location from which peridot is recovered is Buell Park Apache County, Arizona, about 16 kilometers north of Fort Defiance. However, it is estimated that 80% to 95% of the world's production of peridot comes from the San Carlos Reservation.
The peridot occurs as individual grains and aggregates of grains in a basalt which is about 3 to 35 meters thick that forms the top and sides of Peridot Mesa. The material is recovered after it has weathered out of the basalt, in the gullies and canyons which lead down the sides of the Mesa or it is recovered in place in the basalt. The latter method of recovery requires drilling and blasting. The peridot grains that are commercially recovered are typically 6 to 13 millimeters in size. Therefore, the faceted stones produced from this material are generally about 1 carat in size; 2 to 3 carat stones are not uncommon, but stones, particularly flawless ones, 5 carats and over are unusual. Stones as large as 15 and 22 carats have been cut from San Carlos peridot.
On the Reservation, peridot can be mined only by individual Native Americans or by individual families of Native Americans from the San Carlos Reservation. In the past, the miners have not marketed the peridot directly to the gemstone industry. They marketed the material in random size lots, from as small as a coffee can full to as much as a 55-gallon barrel full, to local brokers or mineral dealers. These local brokers/dealers may or may not sort and grade the material, but they do tend to market to the industry in uniform size lots. Currently, some of the large volume miners are marketing the material directly to the industry and are also contracting for cutting services and are marketing cut stones.
New Mexico.--Gem-quality peridot can be found in deposits at three different locations in New
Mexico. The deposits are in the Buell Park area in McKinley County in the northwestern part of
the State and in Kilbourne Hole and Potrillo Mar depression, both near the Mexican border in the
southeastern part of the State. The color of the material is brown, greenish-brown, yellowish-green,
and the desirable peridot green. Some people believe the material from the Kilbourne Hole area is
superior to the material from the famous Arizona location on the San Carlos Reservation.
Currently, there is no commercial production of material from any of the deposits in New Mexico,
but "rockhounds" and other mineral collectors gather materials from these locations for their own
U.S. Department of the Interior
U.S. Geological Survey
988 National Center
Reston, VA 20192 USA
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