large red-and-black European moth; larvae feed on leaves of ragwort; introduced into United States to control ragwort a heavy reddish mineral consisting of mercuric sulfide; the chief source of mercury
Mercury sulfide (HgS), the chief ore mineral of mercury. It is commonly encountered with pyrite, marcasite, and stibnite in veins near recent volcanic rocks and in hot-springs deposits. It has been used as a bright orange-red pigment in stage makeup (now known to be toxic), painting, and Chinese lacquerwork