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[pahy-rahyt] /ˈpaɪ raɪt/
a very common brass-yellow mineral, iron disulfide, FeS 2 , with a metallic luster, burned to sulfur dioxide in the manufacture of sulfuric acid: chemically similar to marcasite, but crystallizing in the isometric system.
Also, pyrites.
Also called iron pyrites.
Origin of pyrite
1560-70; < Latin pyrītēs < Greek pyrī́tēs, noun use of adj.: of fire, so called because it produces sparks when struck. See pyr-, -ite1
Related forms
[pahy-rit-ik, puh-] /paɪˈrɪt ɪk, pə-/ (Show IPA),
pyritical, pyritous
[puh-rahy-tuh s, pahy-] /pəˈraɪ təs, paɪ-/ (Show IPA),
adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for pyrite
  • Regeneration--can be performed either concurrently with coal pyrite leaching in a single operation or separately.
  • pyrite oxidation is taking place on temporary surfaces, which are constant renewed and buried during mining operations.
  • pyrite and marcasite are dimorphs, minerals that are identical in chemical composition but differ in crystalline form.
  • Not only does the pyrite in coal vary in morphology and size but also in stoichiometry and crystallinity.
  • pyrite was the first mineral to form and it is ubiquitous.
  • pyrite, jarosite, anhydrite and arsenic phases are undersaturated.
  • Late-stage botryoidal pyrite and siderite are present in some deposits.
British Dictionary definitions for pyrite


a yellow mineral, found in igneous and metamorphic rocks and in veins. It is a source of sulphur and is used in the manufacture of sulphuric acid. Composition: iron sulphide. Formula: FeS2. Crystal structure: cubic Also called iron pyrites, pyrites Nontechnical name fool's gold
Derived Forms
pyritic (paɪˈrɪtɪk), pyritous, adjective
Word Origin
C16: from Latin pyrites flint, from Greek puritēs (lithos) fire (stone), that is, capable of withstanding or striking fire, from pur fire
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
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Word Origin and History for pyrite

"metallic iron disulfide, fool's gold," 1550s, from Old French pyrite (12c.), from Latin pyrites, from Greek pyrites lithos "stone of fire, flint" (so called because it glitters), from pyrites "of or in fire," from pyr (genitive pyros) "fire" (see fire (n.)). Related: Pyritic.

Online Etymology Dictionary, © 2010 Douglas Harper
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pyrite in Science
A silver to yellow, metallic, cubic mineral. Pyrite often crystallizes in cubes or octahedrons but also occurs as shapeless masses of grains. It occurs in most types of rocks, and is used as a source of iron and in making sulfur dioxide. It is a polymorph of marcasite. Because of its shiny look and often yellow color, it is sometimes mistaken for gold and for this reason is also called fool's gold. Chemical formula: FeS2.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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