ORPIMENT (auripigmenlum), arsenic trisulphide, AsjSj, or yellow realgar (q.v.), occurring in small quantities as a mineral crystallizing in the rhombic system and of a brilliant goldenyellow colour in Bohemia, Peru, etc. For industrial purposes aH artificial orpiment is manufactured by subliming one part of sulphur with two of arsenic Irioxide. The sublimate varies in colour from yellow to red, according to the intimacy of the combination of the ingredients; and by varying the relative quantities used many intermediate tones may be obtained. Tliese artificial preparations are highly poisonous. Formerly, under the name of " king's yellow," a preparation of orpiment was in considerable use as a pigment, but now it has been largely superseded by chrome-yellow. It was also at one time used in dyeing and calico-printing, and for the unhairing of skins, etc.; but safer and equally efficient substitutes have been found.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)