Chrysoprase
Chalcedony (quartz)JewelryWiki Editorial·2 sources·Reviewed 2026-08-04
Apple-green chalcedony, coloured by nickel rather than by chromium as emerald is. It is the most valuable of the chalcedonies and the one most often imitated by dyed green agate — and unlike most chalcedony, its colour can fade with heat and prolonged sunlight.
Properties
| Property | Value | Authority |
|---|---|---|
| Mohs hardness | 7 [1] | — |
| Specific gravity | 2.55–2.91 [1] | — |
| Chemical formula | SiO2 Read from the species entry, Chalcedony. A variety shares its species’ formula. [2] | — |
| Crystal system | Hexagonal (trigonal), microcrystalline [1] | — |
| Common treatments | Dyeing is listed by IGS among chalcedony’s typical treatments. Dyed green chalcedony is sold as chrysoprase, so the distinction matters commercially. [1] | — |
| Care cautions | Keep out of prolonged sunlight and away from heat. Avoid solvents, which can lift dye from imitations. [1] | — |
Sources
- International Gem Society — gemstone articles — International Gem Society (IGS, gemstone information articles (gemsociety.org))
- Handbook of Mineralogy — Mineral Data Publishing / Mineralogical Society of America (Handbook of Mineralogy, Mineral Data Publishing)