A variety of chalcedony, chrysoprase is a cryptocrystalline quartz gemstone. Transparency ranges from nearly opaque to nearly transparent. Its colors range from apple to olive green and nearly pure greens with medium tones.
While some chalcedony varieties, such as “mtorolite” from Zimbabwe, may derive their green color from chromium, chrysoprases get their color from nickel.
Sometimes, the term “prase” is used to described chrysoprase gems with darker tones. However, prase is also used to refer to green chalcedonies colored by chlorite inclusions found in Europe.
Very fine, highly saturated chrysoprase gems have been misidentified as “Imperial jade.”
Locations near Kalgoorlie, Western Australia have yielded 700 and 1,470 kg nodules.
Chrysoprase jewelry may fade if exposed to sunlight or heat. The color may return if stored with moisture (such as soft cotton moistened with water). (Editor’s Note: contributor and jewelry maker Howard Denghausen writes that only dyed chrysoprases will fade in sunlight).
This gemstone requires no special care. A combination of mild detergent, warm water, and a soft brush is a good choice for cleaning. Consult our gemstone jewelry cleaning guide for more recommendations.