CHRYSOPRASE, CHRYSOPRASUS krĭs’ əprāz, the ancient name of a golden-green precious stone (Rev 21:20) generally thought to have been a variety of beryl (q.v.). The term also may have been used to refer to other goldengreen precious stones. During the Middle Ages it was one of the precious stones to which was attributed the facility of shining in the dark. In mineralogy the term is now used for an apple-green variety of chalcedony (q.v.), the color of which is prob. due to the presence of nickel oxide amongst the fine grained silica.