Sulfur is produced as elemental sulfur from the cap rock overlying salt domes; from sedimentary and volcanic deposits; and from hydrogen sulfide in sour-gas and sour-oil fields. It is produced as sulfur compounds from pyrite, pyrrhotite, and marcasite ores and as sulfur dioxide gas in the smelting of sulfide ores.

Salt domes are present in Texas and Louisiana along the north shore of the Gulf of Mexico, and on the Isthmus of Tehuantepec along the south shore of the Gulf of Mexico. The recovered sulfur--also classed as elemental--is produced with gas along the Foothills belt at the eastern edge of the Rocky Mountains, from the northern part of Canada southward to and including the Permian basin of Texas and New Mexico; along the south side of the Ouachita folded belt of Texas, Arkansas, and Mississippi; and on the eastern side of the Pyrenees Mountains in southern France. Many sedimentary deposits are found on several continents and iron sulfide ores also are found in numerous places.

Sulfide has more than 70 uses in industry, but the greatest is in the manufacture of sulfuric acid. The production from sources containing elemental sulfur is nearly equal to the production from sulfur compounds. In 1963, demand for sulfur had approached the capacity to produce; the demand should increase more rapidly than production and the finding of new deposits, unless an increase in price stimulates exploration and resultant discovery of new sources or revival of old ones.