- an orthorhombic mineral, FeS, that is dimorphic with pyrite; iron sulfide
- this mineral cut and mounted on silver or other white metal to look like brilliants
Origin of marcasiteFrench marcassite ; from Medieval Latin marcasita ; from Arabic marqashītā ; from Persian marqashīshā
- A mineral with the same composition as pyrite, FeS2, but differing in crystal structure. Also called white iron pyrites.
- An ornament of pyrite, polished steel, or white metal.
Origin of marcasiteMiddle English, from Medieval Latin marcasīta, from Arabic marqašī&tlowmac;ā, from Aramaic marq&schwa;šitā, from Akkadian mar&hlowbrev;ašu, from mar&hlowbrev;aši, ancient region in the eastern Iranian plateau.
(countable and uncountable, plural marcasites)