Chrysoprase gemstone has been known from the time of the ancient Greeks and Romans.
Chrysoprase, chrysophrase or chysoprasus is a variety of chalcedony that belongs to the quartz family (a cryptocrystalline form of silica) which contains small quantities of nickel, It's one of the most expensive and rare semi-precious stones having a beautiful apple green colour.
The color of chrysoprase is normally apple-green, but varies to deep green. The darker varieties of chrysoprase are also referred as prase. Its color is due to trace amounts of nickel in its composition.
The name of this gemstone is a combination of two Greek words, "chyros" which means: gold and "prase" which means: leek.
Chrysoprase is composed of crystals so fine that they cannot be seen as distinct particles under normal magnification and because of that it's considered as cryptocrystalline. The formula of the gemstone is SIO2 and its hardness according to the Mohs scale is: 6-7.
