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(mär`kəsīt) or

white iron pyrites,

a mineral closely resembling and having the same chemical composition (FeS2) as pyritepyrite
or iron pyrites
, pale brass-yellow mineral, the bisulfide of iron, FeS2. It occurs most commonly in crystals (belonging to the isometric system and usually in the form of cubes and pyritohedrons) but is also found in massive, granular, and stalactite
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. It differs from pyrite in that it is paler in color, becomes darker upon oxidation, and crystallizes in the orthorhombic system. Twinned crystals resembling cockscombs (cockscomb pyrites) or spearheads (spear pyrites) are of common occurrence. The mineral occurs in marls, clays, and limestones in many parts of the world.



(also white iron pyrite), a mineral, a polymorphic variety of natural disulfide of iron, FeS2. Marcasite crystallizes in the orthorhombic system. The luster is metallic. Of bronze-yellow color, which changes to gray along the crystal surface, the mineral forms spear-shaped, often complex, twin crystals, comb-like and round concretions, or sooty black masses (melnikovitemarcasite). Marcasite has a hardness of 6-6.5 on Mohs’ scale and a density of 4,850- 4,900 kg/m3. It usually forms from natural subacid solutions at temperatures lower than the temperature at which pyrite forms. Marcasite is found in hydrothermal deposits in association with pyrite, pyrrhotite, and other sulfides; it often replaces pyrrhotite in the oxidized zone of sulfide deposits. Marcasite occurring in sedimentary rocks is particularly widespread in Carboniferous deposits containing sand and clay, where it forms irregular nodular and concretionary formations. The mineral is used in the preparation of sulfuric acid.


Mineraly; Spravochnik, vol. 1. Moscow, 1960.


FeS2 A pale bronze-yellow to nearly white mineral, crystallizing in the orthorhombic system; hardness is 6-6.5 on Mohs scale, and specific gravity is 4.89.


a metallic pale yellow mineral consisting of iron sulphide in orthorhombic crystalline form used in jewellery. Formula: FeS2
References in periodicals archive ?
Field evidence, ore microscopy, and electron microprobe analyses of the lodes suggest that the vein mineralization commenced with pre-ore precipitation of diagenetic marcasite, pyrite, and minor gel-like colloform textured schalenblende and galena particularly in the vein--wall contacts (Akande and Mucke, 1993).
8, Necklace in silver with marcasite, POMELLATO, Bamboo cuff in sterling silver, GUCCI, Make Love Not War silver ring, EEVA ATTLING, Divorced with Children silver ring, EFVA ATTLING, Perlee white gold ring.
The going was testing, but they managed to complete the card in conditions that proved just the ticket for Mister Marcasite, who shaped well on soft ground on his first two starts but flopped on quicker ground since.
Pyrite, marcasite, dolomite, calcite, kaolinite, epsomite, and idrialin (named after Idrija) represent the main gangue or waste rocks (Mlakar, 1967, 1969; Mlakar and Drovenik, 1971).
Sterling Silver Marcasite & Garnet Glass Heart Pendant: [begin
The mineralogy of the Copper lodes consists of chalcopyrite, pyrite, chalcocite, covellite and marcasite.
Sourced from around the world there is also a fabulous range of 1920-1980s jewellery including genuine 1920s jet beaded, 1950s original milk-glass and sterling silver and marcasite brooches.
Has Finest Waterford & Orrefors Crystal Giftware, Budget Priced Judith Jack Marcasite Jewelry & Top-Of-The-Line Memoire Diamond Rings & Ann.
Mineralogy tests reveal a direct relationship between the recovery of sulphides and metals, the key sulphides being pyrite, marcasite and the silver mineral being pyrargerite.
Silver marcasite and mother of pearl bracelet, pounds 75, from The Jewel Box; rhinestone hoop earrings, pounds 15, from Evans; and a jewel flower pendant, pounds 15, from Dorothy Perkins.
There are divided display cases with crosses, cuff links and tie tacks and marcasite jewelry.