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. 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.