Iron and sulphur powders on watch-glasses with derivatives of these chemical elements. Iron (Fe) is a metal that is extracted from ores in the ground and used extensively in construction and manufacturing. Sulphur (S) is a reactive element mined from subterranean sources by the use of superheated steam. It is mainly used in the production of sulphuric acid, an important industrial chemical. Also seen is a mixture of iron and sulphur (lower left) and a compound of iron and sulphur, iron sulphide (FeS2, lower right).