- 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
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for pegmatite
The specimen was taken from a pegmatite dike at its contact with an amphibolite.The Long Labrador Trail
In North Carolina sapphire has been found in pegmatite dikes.
Pebbles and blocks of Pegmatite covered the bed of the creek.Journal of an Overland Expedition in Australia
The deep-zone minerals are not unlike the pegmatite minerals in their grouping and associations.
The zirconium silicate, zircon, is a fairly common accessory constituent of granitic rocks and pegmatite veins.
- 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
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
- 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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