Sanidine - Wikipedia
Sanidine is the high temperature form of potassium feldspar with a general formula K(AlSi 3 O 8). [2] Sanidine is found most typically in felsic volcanic rocks such as obsidian, rhyolite and trachyte. Sanidine crystallizes in the monoclinic crystal system. Orthoclase is a monoclinic polymorph stable at lower temperatures.
Sanidine: The feldspar mineral Sanidine information and pictures
Detailed description, properties, locality information guide about the potassium feldspar mineral sanidine.
K-feldspar - University of North Dakota
Sanidine is the common K-feldspar in silicic volcanic rocks. In general, keys to identifying K-feldspar are its (lack of) color, its low birefringence, and its twinning. In thin section, microcline, orthoclase and sanidine are distinguished by their twinning, optical sign, and 2Vo.
Sanidine | Silicate, Feldspar, Alkali | Britannica
Sanidine, alkali feldspar mineral, a high-temperature form of potassium aluminosilicate (KAlSi3O8) that sometimes occurs in surface rocks. Sanidine forms colourless or white, glassy, transparent crystals in acidic volcanic rocks.
Sanidine: Mineral information, data and localities. - mindat.org
The high-temperature, fully disordered (in its Al and Si distribution), form of K-feldspar; other potassium-dominant feldspars are microcline (fully ordered) and orthoclase (partly ordered). It is metastable at room temperature, and can revert to orthoclase over long geological periods.
Sanidine - Clark Science Center
Photomicrograph of Sanidine (x20). Example of a non-twinng, well formed crystal face (010) with the x-axis parrallel to the plane running northeast to southwest. In this image you can see the negative/low relief that help distinguish from other K-Spars.
Sanidine - an overview | ScienceDirect Topics
Sanidine (K, Na) (AlSi 3 O 8) is the monoclinic high-temperature alkaline K-Na feldspar, which usually contains about 30%, but sometimes up to 62% sodium (Ab) component. It is found only in young volcanic discharges or volcanic rocks (rhyolite, trachyte, and dacite).
Sanidine Mineral Data
Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern. Blocky - Crystal shape tends to be equant (e.g. feldspars). Massive - Granular - Common texture observed in granite and other igneous rock. Prismatic - Crystals Shaped like …
Sanidine Mineral Physical - Optical Properties, Uses and Occurrence
2023年4月23日 · A member of the solid-solution series of potassium and sodium feldspars, sanidine is the high-temperature form of potassium feldspar, forming at 1,065°F (575°C) or above. Crystals are usually colorless or white, glassy, and transparent, but they may also be gray, cream, or occur in other pale tints.
Sanidine - Encyclopedia
Sanidine is the alkaline feldspar of acidic volcanic rocks (rhyolites) and intermediates (trachytes) where it commonly forms beautiful white or gray crystals, vitreous, often cracked. It has a more disorderly structure than orthoclase or microcline ; sodium …
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