Pyrite is an iron sulfide, with the chemical formula FeS₂. Known as “fool's gold” because of its golden metallic luster, it was often mistaken for gold. Pyrite is an abundant mineral, formed in a wide variety of geological settings.
It crystallizes in the cubic system and generally occurs as well-defined cubes, sometimes octahedral or in massive clusters. With a hardness of 6 to 6.5 on the Mohs scale, pyrite is relatively hard and resists scratching well. In addition to its metallic luster and brassy yellow color, it has a brilliant sheen that makes it easily identifiable.