Cinnabar
Cinnabar, the chief ore of mercury. It is a heavy, red mineral composed of mercury and sulfur, and is usually found in association with geologically young volcanic rocks. Large deposits of cinnabar occur in only a few parts of the world. The largest are in Spain and Italy; other sources include Ukraine, Mexico, China, and the western United States. Mercury is extracted by roasting the crushed ore in furnaces or retorts.
Cinnabar is red mercuric sulfide, HgS. Its hardness ranges from 2 to 2.5.