Pyrite or Fool's gold

   Pyrite, or iron pyrites, as it is commonly called, is a mineral found throughout the world. Because of its glinting, brassy-yellowish appearance, it has many times been mistaken for gold, and is some-times called "fool's gold."
   The name pyrite is derived from the Greek word meaning "fire" because of the sparks which occur when it is struck with steel. Pyrite will also sustain fire, due to its sulfur content.
   Pyrite is the commonest of the sulfide minerals. It is found associated with other sulfides, with oxides, and in quartz veins, in sedimentary and metamorphic rocks, in coal beds. It is also a replacement mineral found in fossils.
   In some countries, where sulfur is not common, pyrite is used to obtain pure sulfur, but in the United States it is used commercially mainly for sulfuric acid. The formula for pyrite is FeS2.