The composition of K-feldspar from three types of pegmatite is presented in Table 2 (K-feldspar is absent from type-IV pegmatites). Systematic chemical varia-tions among the feldspars from the different zones into a pegmatite body are absent. Hence, we will only con-sider the variations among the different types of peg-matite.

Higher fusibility and strength in ceramics. Feldspar and pegmatite can be used as the main vitrifying or fluxing agents in ceramic bodies. As feldspar melts gradually over a range of temperatures, it greatly facilitates the melting of quartz and clays and, thanks to an appropriate mixing, it allows modulations of the melting stage.

 · Abstract The presence of amazonitic K-rich feldspar is considered an earmark of evolved granitic pegmatites of NYF type. Elements of an explanation of the "NYF pegmatite-amazonite" connection emerged in a study of the classic Anjanabonoina "hybrid" granitic pegmatite in Madagascar.

Feldspar minerals are essential components in igneous, metamorphic and sedimentary rocks, to such an extent that the classification of a number of rocks is based on their feldspar content. Although highly present in …

 · Temperatures of crystallization for all or portions of three thin granitic pegmatite dikes in southern California are derived from feldspar solvus thermometry, with supporting data from the K/Cs ratio of K-feldspar, the extent of Al/Si order in K-feldspar, and the texture of granophyre found along the margins of dikes. Although K-feldspars …

 · K-feldspar from albite-spodumene pegmatite is represented by two generations: early microcline-I and late microcline-II. Rb, Cs, Li, and Tl are the most typical impurity elements in K-feldspar that replace K in its crystal lattice. Microcline-II differs from microcline-I: (i) relatively high contents of Rb (6520 and 4490 ppm, respectively), Cs ...

The Covide pegmatite exhibit an unusual striped texture of centimetric layers of K-feldspar/albite alternating with quartz. The outcrop is almost circular with about a dozen …

 · As the content in trace-element in K-feldspar show systematic variations in the progression from the border to the most internal units of a pegmatite, and even across the same megacrystal (Černý, 1994), five samples were taken in the intermediate zone of each pegmatite in such a way so that all results are comparable. In general, all of the ...

 · K-feldspar from albite-spodumene pegmatite is represented by two generations: early microcline-I and late microcline-II. Rb, Cs, Li, and Tl are the most typical impurity elements in K-feldspar that replace K in its crystal lattice.

This departure from cotectic-to-eutectic or peritectic termination of ordinary granitic crystallization generates zoning in textures and feldspar assemblages, controlled by melt …

 · ： Medium-Fine-Grained Biotite K-Feldspar Granite ： ： ： （China） （） ： 23131117101 ： ；； ...

 · K-feldspar Trace elements P 2O 5 Pegmatite Altay ABSTRACT Trace elements of potassium feldspar (Kfs) from pegmatite veins in the Keketuohai pegmatite district were determined in situ by LA-ICP-MS. As the K/Rb ratio decreases, the contents of compatible Ba and Sr decrease, while the contents of incompatible Li, Cs and Ga increase.

 · Occurence. Feldspars are present in almost all magmatic and metamorphic rocks, but are less common in sedimentary rocks because of their low mechanical and chemical stability. Generally, magmatic rocks …

 · Abundant reserves of Na-feldspar (albite) and K-feldspar (orthoclase or microcline) are found in granites, syenite, tracite and pegmatites. As both feldspar …

Pegmatites are rocks composed of several minerals, usual feldspar with potassium, quartz and kaolin. This gives them a natural fluxing capability and, thanks to their low level of …

 · This study utilizes LA-ICP-MS-determined minor and trace element contents of megacrystic blocky K-feldspar to reveal the chemical variability and fractionation degree of albite-spodumene and barren feldspar pegmatites of the Kolmozero lithium deposit in the Kola region, Russia. K-feldspar from albite-spodumene pegmatite is represented by two …

1  · Click here to view K Feldspar data Locality Data: Click here to view New Hope claims, Crystal Mountain Pegmatite Mining District (Storm Mountain Mining District), Larimer County, Colorado, USA Nearest other occurrences of K Feldspar 40.3km (25.0 miles) ⓘ

Trace Elements in K-Feldspar From Nyf and LCT Pegmatites of the Strzegom–Sobótka Granitic Massif, Sudetes, SW Poland. A Reconnaissance Study

 · K-feldspar, Quartz and Biotite in a Granite. This view shows two large flakes of brownish green biotite and minor hornblende (darker smaller grains) near the left edge; the hornblende does not have a distinctive …

 · Within two individual pegmatite bodies, the K/Cs ratio of K-feldspar initially falls more rapidly than the Rayleigh model predicts. That might reflect a local increase in the concentration of Cs relative to K due to the pile-up of incompatible elements in a boundary layer of melt adjacent to the crystal growth front.

 · As the content in trace-element in K-feldspar show systematic variations in the progression from the border to the most internal units of a pegmatite, and even across …

DOI: 10.1016/J.GEXPLO.2017.11.015 Corpus ID: 134068471; K-feldspar composition as an exploration tool for pegmatite-type rare metal deposits in Altay, NW China @article{Tang2018KfeldsparCA, title={K-feldspar composition as an exploration tool for pegmatite-type rare metal deposits in Altay, NW China}, author={Yong Tang and Hong …

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In most geological categories of granitic pegmatites, the feldspar minerals crystallize under conditions of disequilibrium fractionation facilitated by increasing concentration of some or all of H 2 O,F,B,P, and Li. This departure from cotectic-to-eutectic or peritectic termination of ordinary granitic crystallization generates zoning in textures and feldspar assemblages, …

 · Contemporary applications for feldspar include as a flux in glassmaking, ceramic and glaze production. Outside of fluxes, feldspars find broad uses as fillers for plastics, as abrasives and as hardcore aggregates. African Pegmatite is a leading supplier of the complete spectrum of feldspar materials, milled in house to grind sizes suitable for ...

 · K-feldspar from albite-spodumene pegmatite is represented by two generations: early microcline-I and late microcline-II. Rb, Cs, Li, and Tl are the most …

 · Pegmatite is an intrusive igneous rock made up of large interlocking crystals.The word "pegmatite" comes from the Greek word pegnymi, which means "to bind together," referring to the entwined …

 · The presence of an amazonitic K-feldspar ultimately signals net additions of Pb, U, Th, and the alkalis to the source prior to anatexis during a period of distension after a major orogenic disturbance. ... Plumbian K-feldspar also occurs in granitic pegmatite bodies formed by anatexis in the vicinity of a galena-bearing orebody (e.g., at Broken ...

 · The geochemistry of K‐feldspar for K, P, Sr, Ba, Rb, Cs, Ga, and of muscovite for the same elements plus Nb and Ta, was used for proving the parental relationships of S‐type granites and LCT (Li, Cs, Ta) rare‐element pegmatites in the southernmost pegmatitic field of the Pampean pegmatite province in Argentina.

 · K-feldspar is an accessory mineral in the matrix between graphic microcline perthites. It is marked by a low and diffusely streaked CL, similar to that of the K-feldspar …

 · 1. Introduction. Granitic rare-element pegmatites host several economic commodities, such as the lithium hosted in spodumene and petalite, the rubidium contained in lepidolite and K-feldspars, cesium in pollucite, the beryllium in beryl, and the niobium …

 · Download scientific diagram | General fractionation trends for key pegmatite indicator minerals (modified from Breaks et al., 2003). All potassium feldspar, mica, columbite-tantalite, and ...

 · Big crystal of orthoclase K-feldspar from pegmatite. Photo Formats. 3592 × 2395 pixels • 12 × 8 in • DPI 300 • JPG. 1000 × 667 pixels • 3.3 × 2.2 in • DPI 300 • JPG. 500 × 334 pixels • 1.7 × 1.1 in • DPI 300 • JPG. Show more. Photo Contributor. Z. Zbynek Burival. Related keywords. feldspar. orthoclase. background. black ...