Pyrite is a very common mineral, found in a large variety of rocks, including meteorites.
The name Pyrite comes from the Greek pyr, meaning fire, referring to glossy sparks released by fire whenever hit with steel. Pyrite golden-yellow metallic color often leads people to mix it with gold, thus the nickname ‘fool´s gold’.
Its main use is as sulphur source to manufacture sulphuric acid, and less frequently, as iron source. It is also used as a gemstone, but it is sold as Marcasite.
Source: MM Gerdau - Museu das Minas e do Metal -