• synonyms


  1. any member of a group of minerals, hydrous silicates of aluminum with other bases, chiefly potassium, magnesium, iron, and lithium, that separate readily into thin, tough, often transparent, and usually elastic laminae; isinglass.
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Origin of mica

First recorded in 1700–10, mica is from the Latin word mīca crumb, morsel, grain
Related formsmi·ca·like, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for mica

Contemporary Examples

Historical Examples

  • The consequence was a vibration of the mica diaphragm to which the stylus was attached.

  • We can look upon the demand for mica as being in a certain sense settled.

  • The mica has more than paid the working of the mine, and all the rest is clear profit.

  • They are mining for mica, but the mine is more valuable in other respects than it is as a mica property.

  • It is thus, thought we, that our manufacturers of fancy wax deal by their mica.

British Dictionary definitions for mica


  1. any of a group of lustrous rock-forming minerals consisting of hydrous silicates of aluminium, potassium, etc, in monoclinic crystalline form, occurring in igneous and metamorphic rock. Because of their resistance to electricity and heat they are used as dielectrics, in heating elements, etc
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Derived Formsmicaceous (maɪˈkeɪʃəs), adjective

Word Origin

C18: from Latin: grain, morsel
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

Word Origin and History for mica


1706, from specialized use of Latin mica "crumb, bit, morsel, grain," originally *smika (form probably influenced by Latin micare "to flash, glitter"), from PIE *smik- "small" (cf. Greek smikros, Attic mikros "small;" Old High German smahi "littleness"). Related: Micaceous "containing mica."

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Online Etymology Dictionary, © 2010 Douglas Harper

mica in Science


  1. Any of a group of hydrous aluminosilicate minerals with the general formula (K,Na,Ca)(Mg,Fe,Li,Al)2-3(Al,Si)4O10(OH,F)2that can be split easily into thin, partly transparent sheets. Mica is common in igneous and metamorphic rocks and often occurs as flakes or sheets. It is highly resistant to heat and is used in electric fuses and other electrical equipment. Muscovite and biotite are types of mica
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.