ORPIMENT (auripigmentum), in Natural History, a mineral which is composed of sulphur and arsenic, found native in the earth, and constituting one of the ores of arsenic, but sometimes artificially prepared. It is of two kinds, red and yellow. See ARSENIC, MINERALOGY Index, and ARSENIC under ORES, Reduction of.

ORPINE. See SEDUM, BOTANY Index.