石せき黄おうせきおうMeanings1nounorpimentA mineral, arsenic trisulfide, historically used as a pigment. Technical term; rarely encountered outside specialized contexts.石せき黄おうは、かつて黄おう色しょく顔がん料りょうとして使つかわれた鉱こう物ぶつです。Orpiment is a mineral that was once used as a yellow pigment.