This is the polished green chrysoprase sphere. Diameter 2″ (52mm). Weight – 5.6oz (160 grams). Origin: Kazakhstan.
Some information about chrysoprase:
Chrysoprase is a gemstone variety of chalcedony that contains small quantities of nickel. Its color is normally apple-green, but varies to deep green. The darker varieties of chrysoprase also referred to as prase.
Chrysoprase is cryptocrystalline, which means that it is composed of crystals so fine that they cannot be seen as distinct particles under normal magnification. Unlike many non-transparent silica minerals, it is the color of chrysoprase, rather than any pattern of markings, that makes it desirable. The word chrysoprase comes from the Greek chrysos meaning ‘gold’ and prasinon, meaning ‘green’.
As with all forms of chalcedony, chrysoprase has a hardness of 6–7 on the Mohs hardness scale and a conchoidal fracture like flint.