[ mahr-kuh-sahyt ]
/ ˈmɑr kəˌsaɪt /


Also called white iron pyrites. a common mineral, iron disulfide, FeS2, chemically similar to pyrite but crystallizing in the orthorhombic system.
any of the crystallized forms of iron pyrites, much used in the 18th century for ornaments.
a specimen or ornament of this substance.

Origin of marcasite

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


mar·ca·sit·i·cal [mahr-kuh-sit-i-kuh l] /ˌmɑr kəˈsɪt ɪ kəl/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for marcasite

British Dictionary definitions for marcasite

/ (ˈmɑːkəˌsaɪt) /


a metallic pale yellow mineral consisting of iron sulphide in orthorhombic crystalline form used in jewellery. Formula: FeS 2
a cut and polished form of steel or any white metal used for making jewellery

Derived forms of marcasite

marcasitical (ˌmɑːkəˈsɪtɪkəl), adjective

Word Origin for marcasite

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

Science definitions for marcasite

[ märkə-sīt′, -zīt′ ]

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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.