[ peg-muh-tahyt ]

  1. a coarsely crystalline granite or other high-silica rock occurring in veins or dikes.

Origin of pegmatite

1825–35; <Greek pēgmat- (stem of pêgma) anything fastened together, a bond (compare pēgnýein to stick) + -ite1

Other words from pegmatite

  • peg·ma·tit·ic [peg-muh-tit-ik], /ˌpɛg məˈtɪt ɪk/, adjective

Words Nearby pegmatite Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use pegmatite in a sentence

British Dictionary definitions for pegmatite


/ (ˈpɛɡməˌtaɪt) /

  1. any of a class of exceptionally coarse-grained intrusive igneous rocks consisting chiefly of quartz and feldspar: often occurring as dykes among igneous rocks of finer grain

Origin of pegmatite

C19: from Greek pegma something joined together

Derived forms of pegmatite

  • pegmatitic (ˌpɛɡməˈtɪtɪk), adjective

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

Scientific definitions for pegmatite


[ pĕgmə-tīt′ ]

  1. Any of various coarse-grained igneous rocks that often occur as wide veins cutting across other types of rock. Pegmatites form from water-rich magmas or lavas that cool slowly, allowing the crystals to grow to large sizes. Although pegmatites can be compositionally similar to a number of rocks, they most often have the composition of granite.

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