Under BGS terminology, a pegmatitic rock (for example, a pegmatitic gabbro) is a coarse-grained rock containing patches of much coarser-grained rock of essentially the same composition. [7] Individual crystals in pegmatites can be enormous in size.

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.

Pegmatites are most commonly formed as coarse-grained igneous rocks of granitic composition, containing large clasts of gemstones such as amazonite, garnet, and topaz. Phaneritic (phaner = visible) textures are typical of intrusive igneous rocks, these …

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.

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 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.

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.

Jun 13, 2018 · Pegmatite is called an intrusive igneous rock because it forms when magma solidifies under the Earth's surface. In contrast, when magma solidifies outside the Earth's surface, it forms an extrusive igneous rock. The process by which pegmatite is formed explains why its crystals are so large:

Silica undersaturated (without quartz) magmatic rocks may be also pegmatitic. The term “pegmatite” was first used by a French mineralogist René Haüy, but he used this term as a synonym of graphic granite.

The meaning of PEGMATITE is a coarse variety of granite occurring in dikes or veins.