Chrysoprase

Chrysoprase

Chrysoprase is a green variety of chalcedony which is cryptocrystalline quartz. Its green colour is due to the presence of nickel impurities in the form of oxides or silicates of nickel. It can vary from a greenish yellow to a clear apple green. It is usually cut en cabochon, or into beads, and is also used for intaglios and cameos. Imitations of chrysoprase are made by the staining of agate.

Sources

Chrysoprase was known from ancient Greek and Roman times, although its ancient source is not known. It has been found at Zabkowice in Silesia, the Urals, California, and other parts of the USA.