Pyrites : (Min. Sulphide of iron (FeS2). Brassy yellow, commonest sulphide mineral. Also known as fool's gold, or iron pyrite. Also copper pyrite or chalcopyrite, which has a similar appearance and is a sulphide of copper and iron
H. J. Porter (Chairman - Technical Committee), Dictionary of Fire Technology, The Institution of Fire Engineers, The Victory Press (Leicester) Ltd. 1979 UK. (Fr Tech - Brit) {81}