[ mahr-kuh-sahyt ]

  1. Also called white iron pyrites . a common mineral, iron disulfide, FeS2, chemically similar to pyrite but crystallizing in the orthorhombic system.

  2. any of the crystallized forms of iron pyrites, much used in the 18th century for ornaments.

  1. a specimen or ornament of this substance.

Origin of marcasite

1375–1425; late Middle English <Medieval Latin marcasīta<Arabic marqashīṭā<Aramaic marqəshītā

Other words from marcasite

  • mar·ca·sit·i·cal [mahr-kuh-sit-i-kuhl], /ˌmɑr kəˈsɪt ɪ kəl/, adjective

Words Nearby marcasite Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use marcasite in a sentence

British Dictionary definitions for marcasite


/ (ˈmɑːkəˌsaɪt) /

  1. a metallic pale yellow mineral consisting of iron sulphide in orthorhombic crystalline form used in jewellery. Formula: FeS 2

  2. a cut and polished form of steel or any white metal used for making jewellery

Origin of marcasite

C15: from Medieval Latin marcasīta, from Arabic marqashītā, perhaps from Persian

Derived forms of marcasite

  • marcasitical (ˌmɑːkəˈsɪtɪkəl), adjective

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for marcasite


[ märkə-sīt′, -zīt′ ]

  1. A light yellow to gray, metallic, orthorhombic mineral. Marcasite is a polymorph of pyrite and looks similar to it but has a lower specific gravity, is paler in color, and often has a radiating fibrous structure. Chemical formula: FeS2.

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