A pegmatite is an igneous rock showing a very coarse texture, with large interlocking crystals usually greater in size than 1 cm (0.4 in) and sometimes greater than 1 meter (3 ft). Most pegmatites are composed of quartz, feldspar, and mica, having a …

Pegmatites are extreme igneous rocks that form during the final stage of a magma’s crystallization. They are extreme because they contain exceptionally large crystals and they sometimes contain minerals that are rarely found in other types of rocks.

Apr 12, 2019 · Pegmatite is an igneous rock that form end of the stage a magma’s crystallization. Pegmatites contain exceptionally large crystals and they contain rarely minerals than other types of rocks. They have interlocking crystals usually larger than 2.5 cm in size.

Pegmatite is a coarse-grained igneous rock, renowned for its exceptionally large crystals, Composed mainly of quartz, feldspar, and mica, it shares a similar composition to granite but differs significantly in its texture.

Pegmatite, almost any wholly crystalline igneous rock that is at least in part very coarse grained, the major constituents of which include minerals typically found in ordinary igneous rocks and in which extreme textural variations, especially in grain size, are characteristic.

Pegmatite is an intrusive igneous rock defined by its very large, interlocking crystals that can range in size from 1 cm to over 1 meter. It is usually primarily composed of quartz, feldspar, and mica, but often includes rarer minerals and gemstones. Pegmatite forms in the last stages of magma crystallization

Jun 13, 2018 · Pegmatite is an extremely coarse-grained intrusive igneous rock composed of large interlocking crystals. There is no defined mineralogy for pegmatite; any plutonic rock may form pegmatite. The most common type of pegmatite is made of granite.

Pegmatite is a very coarse-grained igneous rock. Simple pegmatites are composed of large crystals of ordinary minerals. Here is a sample of alkali feldspar granite pegmatite from Northern Norway which is composed of alkali feldspar (pink), quartz (gray) and …

May 18, 2018 · A pegmatite is an intrusive igneous body of highly variable grain size that often includes coarse crystal growth. A pegmatite may be a segregation within an associated plutonic rock or a dike or vein that intrudes the surrounding country rock .

Pegmatites are very widespread but constitute a tiny fraction of the Earth's crust. These distinctive rocks nonetheless have long attracted attention as assemblages of both common and rare minerals with highly varied crystal form, size, and mutual relationships.