pegmatite

American  

[peg-muh-tahyt] / ˈpɛg məˌtaɪt /

noun

Petrology.

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

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pegmatite British  

/ ˈpɛɡməˌtaɪt, ˌpɛɡməˈtɪtɪk /

noun

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

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pegmatite Scientific  

/ pĕg′mə-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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Other Word Forms

• pegmatitic
  adjective

Etymology

Origin of pegmatite

1825–35; < Greek pēgmat- (stem of pêgma ) anything fastened together, a bond (compare pēgnýein to stick) + -ite ¹

Example Sentences

Barroso, a world heritage site for agriculture since 2018, is one of many lithium-rich areas in northern Portugal and Savannah already mines feldspar, quartz and pegmatite there.

From Reuters • Jun. 8, 2022

A rock that chiefly consists of pegmatitic texture is known as a pegmatite.

From Textbooks • Jan. 1, 2017

Brookfield executives do not look upon pegmatite so kindly.

From New York Times • Jul. 2, 2014

About 45 million years ago, another episode of magmatism sent dikes of granitic pegmatite through the orthogneiss.

From Scientific American • Mar. 7, 2012

The pegmatite dikes of Haddam Neck, Conn., of Stoneham, Me., and of San Diego County, Cal., have furnished splendid aquamarine and other beryl.

From A Text-Book of Precious Stones for Jewelers and the Gem-Loving Public by Wade, Frank Bertram