An abundant tasteless odorless multivalent nonmetallic element; best known in yellow crystals; occurs in many sulphide and sulphate minerals and even in native form (especially in volcanic regions); SYN. S, sulphur, atomic number 16.
Brittle, pale-yellow, nonmetallic element, symbol S, atomic number 16, atomic weight 32.064. It occurs in three allotropic forms: two crystalline (rhombic and monoclinic) and one amorphous. It burns in air with a blue flame and a stifling odor; it is insoluble in water but soluble in carbon disulfide. It is found abundantly in volcanic regions and occurs in nature in combination with metals and other substances, as well as a free, brittle, crystalline solid.
Sulfur is a constituent of proteins. Its greatest industrial use is in the commercial preparation of sulfuric acid to treat phosphate rock in producing fertilizers. It is also used in making paper, matches, gunpowder and fireworks, in vulcanizing rubber, and in medicines and insecticides. It has been known since ancient times and was called sulfur, later sulfur, in Latin.
Between 20 and 50 million metric tons of sulfur are returned from the oceans to the atmosphere every year in the form of dimethyl sulfide (DMS), the gas that gives sea air its bracing smell. DMS is a breakdown product of a salt produced by marine algae to maintain their osmotic balance (see osmosis). Human activity releases about 80 million metric tons of sulfur.