Cinnabar is a bright red mineral consisting of mercury and sulfur. It provides most of the world’s supply of mercury. The chemical formula for cinnabar is HgS. Cinnabar crystals are six-sided, either hexagonal or rhombohedral (see Crystal (Classifying crystals)). Cinnabar rarely appears as large crystals. However, mines in the Hunan Province of China have produced large, gemlike crystals since the early 1980’s. Cinnabar usually occurs in earthy masses or scattered in opal. It is found mostly near the earth’s surface, close to volcanic rocks and hot springs. In addition to China, deposits occur in Italy, Slovenia, and Spain, and in California, Nevada, and Oregon. See also Mercury.
