pyrite science definition

A silver to yellow, metallic, cubic mineral. Pyrite often crystallizes in cubes or octahedrons but also occurs as shapeless masses of grains. It occurs in most types of rocks, and is used as a source of iron and in making sulfur dioxide. It is a polymorph of marcasite. Because of its shiny look and often yellow color, it is sometimes mistaken for gold and for this reason is also called fool's gold. Chemical formula: FeS₂.