marcasite
Pronunciation:
/ˈmɑːkəsʌɪt//ˈmɑɹ.kə.sɑɪ̯t/noun
Definitions
The orthorhombic form of iron disulfide, FeS2, occurring as yellow crystals.
Synonyms:white iron pyrite(jewellery) Pyrite.
Any of various metal sulfides, usually iron sulfide minerals.