Pyrite (FeS2) is a very common mineral found in a wide variety of geological formations from sedimentary deposits to hydrothermal veins and as a constituent of metamorphic rocks. People always mistaking it with gold due to the brassy-yellow metallic colour of pyrite which has been given a nickname as Fools gold'. The oxidation of pyrite in the presence of water will produce acid (H+), sulfates (SO42) and aqueous Fe(II) ions (Fe2+)