Pegmatites

Pegmatites may be composed of a variety of minerals. Terms such as granite pegmatite, gabbro pegmatite, syenite pegmatite, or names with any other plutonic rock type as …

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Mineral-Deposit Model for Lithium-Cesium-Tantalum …

occur in LCT pegmatites, as do a number of gemstones and high-value museum specimens of rare minerals. Individual crystals in LCT pegmatites can be enormous: the largest spod-umene was 14 meters long, the largest beryl was 18 meters long, and the largest potassium feldspar was 49 meters long. Lithium-cesium-tantalum pegmatites …

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Pegmatite | SpringerLink

The most distinctive features of pegmatites are coarseness of grain and great variations of grain size over short distances ().The average grain size for all occurrences probably is …

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Pegmatite

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. Pegmatite is a very coarse-grained ...

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Les GRENATS DES PEGMATITES

PEGMATITES ; Composition des ; granitoïdes ; Origine des ; pegmatites ; Cristallisation des ; Pegmatites ; SYN- CRISTALLISATION ; MSC-GRENAT ; cavité dodécaédrique de 7-8 cm de diamètre dans lalbite avec des résidus de spessartine ce sont les fragments dun seul et même cristal originel 43 ETCHED SPESSARTINES

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Pegmatites | SpringerLink

1981). Pegmatites form from residual silicate melts that are enriched in H 2 O, OH −, CO 2, HCO 3 2−, CO 3 2−, SO 4 2−, PO 4 3−, H 3 BO 3, F −, Cl − and other volatile or semi-volatile components. In principle, any plutonic rock can display pegmatitic structure, an example being very coarse-grained varieties of mafic to ultramafic rocks of …

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Muscovite – paragonite – celadonite diagram showing the composition …

Les pegmatites de type grenat-REE (Ti, Y, HREE) sont des pegmatites NYF, issues de la ségrégation tardive du gneiss granodioritique, avec un contrôle du fractionnement des métaux rares par l ...

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Pegmatite

An unusually coarse-grained igneous rock, with interlocking, equigranular crystals, usually found as irregular dike s, lenses, or vein s, esp. at the margins of batholith s. Most grains are 1 cm or more in diameter. The dykes and veins typically have symmetrical zonations, with crystals growing inwards from the walls.

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TOURMALINE IN PETALITE-SUBTYPE GRANITIC PEGMATITES …

La tourmaline dans les massifs de pegmatite granitique, sous-type à pétalite, dans les régions des lacs Pakeagama et Separation, dans le nord-ouest de l'Ontario, fournit de bons indices de l'évolution des venues magmatiques qui ont cristallisé sous forme de pegmatite et, dans certains cas, été affectées par une réaction entre le magma et les …

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What are Pegmatite Minerals?

Granite pegmatites can be complex in composition and contain a diverse suite of exotic minerals and tend to be enriched in what geologists call "incompatible elements" or "rare elements.". These include cesium, rubidium, lithium, beryllium, tantalum, niobium, tin, boron, and zirconium, along with a few others. They are unusual because ...

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The compositional evolution of pollucite from African granitic pegmatites

Occurrences of pollucite are known from nine highly fractionated granitic pegmatites in Zimbabwe, Namibia and Mozambique. The pollucite is typically associated with spodumene, petalite, amblygonite, quartz and feldspar. The primary pollucite has Si Al (at.) ratios of 2.47 to 2.57 and CRK = 100 (Cs + Rb + K)/ (Cs +, Rb + K + Na + Ca + Li) …

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THE CLASSIFICATION OF GRANITIC PEGMATITES REVISITED

Il y a eu plusieurs tentatives de classification de pegmatites granitiques au cours du siècle dernier, avec un taux de réussite et une applicabilité variables. La structure interne, les relations paragénétiques, la composition chimique globale, les aspects pétrogénétiques, la nature du milieu de croissance, et les caractéristiques ...

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Minerals | Free Full-Text | Evolution and Li Mineralization of …

The Jiajika rare-metal deposit located in western Sichuan Province (China) is renowned as the largest lithium deposit in Asia, and the No. 134 pegmatite dike is the largest lithium pegmatite under mining conditions in the area. On the basis of a detailed characterization of textures and minerals in the Jiajika No. 134 pegmatite, two zones (the …

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Petrological and Geochemical Studies of Lepidolite (LCT …

The non-lepidolite pegmatite has A/CNK values are in the range of 0.333 - 8.630. Most pegmatites with the LCT signature have compositional affinity with S-type granites [69]. These types of pegmatites are usually related to S-type granites of orogenic environments (i.e., subduction zones or continental collision zones) [2] [11] [70] [71] [72].

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Pegmatite Rock – Uses, Facts & Properties – All You Need to …

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.

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Cleavelandite: Mineral information, data and localities.

Geochemistry of the Villismán granite, associated aplite-pegmatites and surrounding Li-pegmatites, Sierra de Ancasti, Argentina. Journal of South American Earth Sciences, 103, 102764. ⓘ Don Arturo pegmatite

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Pegmatite | Properties, Composition, Formation, …

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Properties of Pegmatite | Physical | Thermal

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(PDF) pegmatite

Surface exposure of pegmatite at the San Diego mine, Mesa Grande district, San Diego County, California (USA), inwhich large K-feldspar crystals that constitute …

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Pegmatites | SpringerLink

Pegmatites are intrusive igneous rocks of exceptionally coarse grain size, in which individual crystals can attain up to tens of metres in size. ... depending on the …

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(PDF) The classification of granitic pegmatites …

Une subdivision plus poussée des sous-classes en types et sous-types repose sur des différences plus subtiles des trait s . ... on bulk composition of these pegmatites, the degree of .

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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 …

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THE CLASSIFICATION OF GRANITIC PEGMATITES REVISITED

The classification of granitic pegmatites was frequently attempted during the past century, with variable degrees of success and applicability. Internal structure, paragenetic relationships, bulk chemical composition, petrogenetic aspects, nature of parent medium, and geochemical features were applied. However, all schemes were …

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Les Grenats des Pegmatites

A.ABREAL, Les Grenats des pegmatites J. of Pers. Mineralogist, vol.13, page 149-181, 2010 - Page 151 - Figure 2 : Coupe d'intrusions magmatiques avec genèse de pegmatites 2.4 Classification des pegmatites Nous ne considérerons dans cet exposé, que les pegmatites dites granitiques, en accord avec leur composition.

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Tools and Workflows for Grassroots Li–Cs–Ta (LCT) …

The increasing demand for green technology and battery metals necessitates a review of geological exploration techniques for Li–Cs–Ta (LCT) pegmatites, which is applicable to the work of mining companies. This paper reviews the main controls of LCT pegmatite genesis relevant to mineral exploration programs and presents a …

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Pegmatites and aplites: Their genetic and applied ore geology

The "ore body" of the pegmatite is described by two items—1st order and 2nd order terms, the type of deposit (e.g. metapegmatite, pegmatoid, pseudopegmatite) and by its shape and structure (e.g., stock-like, tabular, miarolitic). The "ore composition" is defined also by two characteristics, labeled as 3rd order and 4th order terms, by ...

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Pegmatite Overview, Texture & Composition | What is …

The varied composition creates extreme variations in coarse textures. Pegmatite Composition. ... Pegmatites are an important source of lithium, gemstones, and other rare earth elements or minerals ...

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Lithium Potential of the Indian Granitic Pegmatites

minerals associated with pegmatites. These minerals are hosted in some 20 pegmatites in south-eastern parts of the pegmatite belt (Singh et al. 1991). Solitary occurrence of spodumene is reported in the Govindpal pegmatite (Deshpande, 1976). Beryl is noted in most of the Li-pegmatites. Cassiterite occurs in innumerable pegmatites either

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Pegmatite: An Intrusive Igneous Rock

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 is an economically …

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Mineral-deposit model for lithium-cesium-tantalum pegmatites

This, in turn, enables pegmatites to form thin dikes and massive crystals despite having a felsic composition and temperatures that are significantly lower than ordinary granitic melts. Lithium-cesium-tantalum pegmatites crystallized at remarkably low temperatures (about 350–550 °C) in a remarkably short time (days to years).

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Assemblages of Li-Cs pegmatite minerals in equilibrium with …

Des expériences précédentes, à 450° et 600°C, ont déterminé la composition des solutions hydrothermales chlorurées en équilibre avec des associations minérales contenant Li, Na et Cs. ... Lagache M (1992) Apport de la Minéralogie expérimentale à la connaissance des équilibres entre fluides et minéraux des pegmatites granitiques ...

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