Around 3500 years ago, fine green gemstones began to show up in Egyptian jewellery. Although ancient literature made allusions to these emerald-like stones, historians could not work out where the fine stones came from. The mystery was solved in the early 20th Century when the ancient mines that produced the stones were rediscovered on the small island of Zagbargad, located in the Red Sea off the coast of Egypt. The secret green stones were Peridot, which is a gem quality variety of the mineral olivine.
Peridot and Diamond are the only gemstones that form in the mantle of the earth rather than the earth’s crust. Most peridot is carried to the surface by volcanic lavas that distort the gemstone’s crystalline form. There are exceptions, however; fine peridot crystals were found on Zagbargad as well as in a recent discovery in the Suppat region of Pakistan. Lesser quality peridot has been recovered from Australia, China, Africa and Myanmar.
The largest deposit of peridot in the world is located on the peridot Mesa within the San Carlos Apache reservation in Arizona. This deposit covers an area of nine square miles. In the 1930’s apache tribe members began to respectfully recover peridot from their lands. Much of this production was supported by Tiffany’s of New York.
Depending on the amount of iron in the stone’s chemical makeup, peridot can range from a brownish or yellow green to a deep grass green. The latter colour is regarded as the finest variety, most desirable in handmade jewellery .
Large faceted stones of peridot are relatively rare and can be quite expensive. Luckily, smaller and more accessibly priced stones are abundant. You’ll find every type of cut in a variety of price points. Some peridot cabochons even display cat’s eye or star patterns.
Peridot is not subject to treatments or enhancements. It has only been synthesized experimentally in the lab, and it’s not documented as a synthetic occurring in the gem trade.
The two most common peridot imitations, especially in handmade jewellery , are glass and green cubic zirconia. Glass imitations will have rounded gas bubbles that you can easily see with a 10-power loupe. Green cz acts likes a prism, dispersing light into a rainbow of colours. This effect can easily be seen without the use of magnification.
Peridot has also come from outer space. Meteorites known as pallasites contain peridot that’s embedded in a nickel-iron matrix. Pallasite Peridot is one of the rarest forms of the stone, very desirable for handmade jewellery .