Pegmatite: Igneous Rock - Pictures, Definition & More - Geology.com
网页It is a granitic pegmatite that intrudes the boundary between two rock units in a dike that is up to two meters wide. It was mined for emeralds by a series of owners, which included Tiffany and Company, between 1894 and the 1990s.
Pegmatite - Wikipedia
网页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 similar silicic composition to granite .
Pegmatite | Properties, Composition, Formation, Uses, Occurrence
网页2019年4月12日 · Tourmaline in pegmatitic granite. 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 Rocks: Identification, Characteristics, Pictures, and More
网页2024年4月30日 · Pegmatite rocks form from the slow cooling of molten rock deep within the Earth’s crust. These unique rocks are a result of specific geological processes that involve the crystallization of minerals in large cavities within the cooling magma.
Pegmatite: An Intrusive Igneous Rock - ThoughtCo
网页2018年6月13日 · 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. Granite pegmatite typically contains feldspar, mica, and quartz.
Pegmatite | Igneous, Minerals, Crystals | Britannica
网页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.
Ore-forming processes within granitic pegmatites - ScienceDirect
网页2018年10月1日 · The vast majority of pegmatites are granitic in composition, and this article pertains to these rocks. Pegmatites occur as segregations near the roofward contact of their source pluton, as dike swarms emanating from their plutons into the surrounding igneous and metamorphic rocks, and as planar to …
Granite Pegmatites Texture Formation and Mineral Composition
网页2022年9月15日 · Granite pegmatites are intrusive igneous rock with granitic composition and unusually large crystals, i.e., more than 0.4 inches (1 cm) with larger crystals more than 1.2 inches (3 cm) and some being several feet in size. However, these rocks may have minerals and rare elements not typical in igneous rock.
(PDF) Granitic pegmatites - ResearchGate
网页1995年11月5日 · The shapes of pegmatites commonly are closely controlled by the type and structure of the wall rock. Many pegmatites in schistose rocks are concordant with regional foliation, and plunge...
Pegmatite - Igneous Rocks - Sandatlas
网页Pegmatite is an exceptionally coarse-grained plutonic igneous rock. Most pegmatites have a mineralogical composition of granite but composition has no defining importance here. Pegmatites may have any imaginative magmatic composition and they are actually known to contain a large number of unusual minerals.