[ peg-muh-tahyt ]
/ ˈpɛg məˌtaɪt /

noun Petrology.

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

Nearby words

  1. pegbox,
  2. pegged tooth,
  3. pegging,
  4. peggy,
  5. pegler,
  6. pegomancy,
  7. pegu,
  8. pegwood,
  9. peh,
  10. pehlevi

Origin of pegmatite

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

Related formspeg·ma·tit·ic [peg-muh-tit-ik] /ˌpɛg məˈtɪt ɪk/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for pegmatite

British Dictionary definitions for pegmatite


/ (ˈpɛɡməˌtaɪt) /


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
Derived Formspegmatitic (ˌpɛɡməˈtɪtɪk), adjective

Word Origin for pegmatite

C19: from Greek pegma something joined together

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

Science definitions for pegmatite


[ pĕgmə-tīt′ ]

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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.