pegmatite composition

  • Pegmatite: Description, Characteristics, and Other FAQs

    The density of pegmatite varies depending on its composition. For example, pegmatite that is mostly quartz has a density of 2.7 grams per cubic centimeter. Pegmatite that is mostly feldspar has a density of 2.6 grams per cubic centimeter. And pegmatite that is mostly mica has a density of 2.9 grams per cubic centimeter. What is the Grain Size ...

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  • Pegmatite Rock – Uses, Facts & Properties

    For instance, when pegmatites have a mineral composition similar to the Granites, such as the predominance of quartz, feldspar, and mica, they usually term as Granite Pegmatites. When the dominance of one of the Common Minerals in Granite Pegmatite takes place, the look-n-feel of the rocks changes accordingly. Quartz Muscovite

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  • Pegmatite | SpringerLink

    Pegmatites are quite different from ordinary igneous rocks in many aspects of texture, yet the distribution, structural relationships, bulk composition, rare-element content, and internal features of many pegmatite bodies strongly suggest an origin involving igneous processes.

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  • (PDF) Rare-Metal Pegmatite Deposits of the Kalba …

    Time chart of rare-metal pegmatites, granite intrusions, and dikes in the Kalba-Narym terrane. Ages of pegmatite are as in Figure 6; ages of dikes are Ar-Ar on muscovite (Chechek intrusion), after ...

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  • Pegmatite

    Pegmatite is a very coarse-grained igneous rock, with a grain size of 20 mm or more.Most pegmatites are composed of quartz, feldspar, and mica; in essence a "granite."Rarer "intermediate" and "mafic" pegmatite containing amphibole, calcium-plagioclase feldspar, pyroxene and other minerals are known, found in recrystallized zones and apophyses …

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  • Granite Pegmatites Texture Formation and Mineral Composition

    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. Such minerals include boron, beryl, topaz, …

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  • ALEX STREKEISEN-Pegmatite-

    Most pegmatites have a composition that is similar to granite (granite pegmatites) with abundant quartz, feldspar, and mica. However, compositions such as gabbro pegmatite, syenite pegmatite, and any other plutonic rock …

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  • COMPOSITION OF A PEGMATITE, KEYSTONE, SOUTH …

    Bulk composition and variations in composition within a structurally simple pegmatite in the southern Black Hills, South Dakota, have been determined from analyses of a set of drill core samples collected from the hanging wall to the footwall. Reliable data of this kind are uncom-mon, for pegmatites have textures and structures that put many dif-

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  • Bulk Composition of Mt. Mica Pegmatite, Maine, USA:IMPLICATIONS For …

    The pegmatite is subparallel to the foliation of the enclosing migmatite, and leucosomes show a gradational contact with the pegmatite where juxtaposed. Texturally, the pegmatite and leucosomes appear to be in equilibrium with no change in grain size or composition where the two are in contact.

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  • Granite Pegmatites Texture Formation and Mineral Composition

    Photo credit: James St. John, Wikimedia, CC BY 2.0. Granitic pegmatites make up the majority of pegmatites. However, pegmatite with syenite, gabbro, or diorite …

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  • Pegmatite

    Most pegmatites have a fairly simple composition: K-feldspar (either orthoclase or microcline) + quartz + some other minerals. Complex pegmatites commonly contain tourmaline, lepidolite, topaz, cassiterite, fluorite, beryl, etc. Pegmatites …

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  • Pegmatite genesis: state of the art

    Most commonly, the term is used to refer to granitic pegmatites and is generally understood to refer to rock of overall granitic composition when it is used without a qualifying adjective ( e.g. gabbroic pegmatite). Granitic pegmatites are composed predominantly of quartz and feldspars with accessory mica. Although no universally accepted model ...

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  • Magma of pegmatites from Volhynia: Composition and …

    The composition of pegmatitic magma was determined by means of an electron and ion microprobe, along with the technique of local infrared spectroscopy. ... mineral association of the inclusions is essentially the same as the rock-forming and accessory minerals of the pegmatite, a fact indicative of their crystallization from the pegmatitic melt ...

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  • Pegmatite: Identification, Pictures & Info for Rockhounds

    Pegmatite is usually granitic in composition, made from large amounts of quartz and alkali feldspar with smaller amounts of plagioclase feldspar, mica, and amphibole. However, some …

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  • Examples of Pegmatites: Granite, Diorite, Gabbro and More

    Most pegmatites have granitic rock composition. However, some may have intermediate to mafic composition but are rare. An example of a mafic pegmatite is gabbro, while diorite is an intermediate one. Most of the other plutonic or intrusive igneous rocks can be pegmatitic. However, they are uncommon except for rocks like syenite or granodiorite.

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  • What is the chemical composition of pegmatite?

    A pegmatite is an intrusive igneous rock comprised of coarse, interlocking mineral grains usually above three centimeters in diameter. Although very many pegmatites are granitic in composition ...

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  • Lithium Pegmatites – Is This the Right One?

    The name pegmatite has nothing to do with the mineral composition of the rock, but rather describes a rock's physical structure. To be called a pegmatite, the rock should be composed almost entirely of crystals that are at least one centimetre in diameter. ... Pegmatites are quite easily recognized if there is an outcrop or other rock ...

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