• synonyms


  1. a mineral of the feldspar group, potassium aluminum silicate, KAlSi3O8, identical in composition with orthoclase but having triclinic instead of monoclinic crystals, used in making porcelain.
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Origin of microcline

1840–50; micro- + -cline < Greek klī́nein to lean1, referring to the angles between its cleavage planes, which differ slightly from 90°
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for microcline

Historical Examples

  • At Danbury the mineral occurs with microcline and oligoclase embedded in dolomite.

    Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 9


  • The common color of microcline is white to pale yellow, but occasionally green and red occur.

  • Orthoclase and microcline feldspar are used in the manufacture of porcelain and chinaware.


    William J. Miller

  • The felspar of the granulites is mostly orthoclase or cryptoperthite; microcline, oligoclase and albite are also common.

British Dictionary definitions for microcline


  1. a white, creamy yellow, red, or green mineral of the feldspar group, found in igneous, sedimentary, and metamorphic rocks: used in the manufacture of glass and ceramics. Composition: potassium aluminium silicate. Formula: KAlSi 3 O 8 . Crystal structure: triclinic
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Word Origin

C19: from German Mikroklin, from mikro- micro- + Greek klinein to lean; so called because its cleavage plane is slightly different from 90°
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

microcline in Science


  1. A white, pink, red-brown, or green type of potassium feldspar. It is dimorphous with orthoclase feldspar, differing from it in shape and in the fact that it forms at lower temperatures.Chemical formula: KAlSi3O8.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.