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see micamica
, general term for a large group of minerals, hydrous silicates of aluminum and potassium, often containing magnesium, ferrous iron, ferric iron, sodium, and lithium and more rarely containing barium, chromium, and fluorine.
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(from Muscovy, the old name for Russia, from where large sheets of the mineral were exported to the West under the name of Muscovy glass), a mineral from the mica group with the empirical formula KA12[[AlSi3O10] • (OH)2. Crystals are tabular and in the monoclinic system. Basal cleavage is extremely perfect. Muscovite is easily split into very thin sheets. This is caused by its crystalline structure, which is composed of three-layer packets of two sheets of aluminum-oxygen and silicon-oxygen tetrahedrons connected through a layer of octahedrons, in the center of which are located aluminum ions, each surrounded by four oxygen ions and two OH groups. One-third of the octahedrons are not filled with aluminum ions. The packets are interconnected through potassium ions.

Muscovite has a hardness on Mohs’ scale of 2.5–3; its density is 2,760–3,100 kg/m3. The mineral is usually colorless; sometimes, light brown, pale green, or other colors. Its luster is vitreous; on the cleavage planes the luster is pearly or silvery. Muscovite is sometimes found as cryptocrystalline masses with a silky luster. In this form it is called sericite.

Muscovite is a widespread mineral and is found as a component of magmagene rocks and also metamorphic rocks such as granites, granite pegmatites, syenites, greisens, crystalline schists, and gneisses. Of industrial significance is the muscovite recovered from pegmatite veins, where the mineral occurs as large crystals or as accumulations measuring 1–2 m thick.

Muscovite is most frequently used in electrical insulation. In industry, it is used in the form of sheet mica (for insulators, condensers, and telephones), mica powder (for roofing paper, mica board, and fireproof paints), and mica products (for electrical insulating gaskets in electric instruments). In the USSR, muscovite deposits are found on the Kola Peninsula and in Eastern Siberia near Mama and Kanska. Muscovite is also found in India, the Malagasy Republic, Canada, the United States, and Brazil.


KAl2(AlSi3)O10(OH)2 One of the mica group of minerals, occurring in some granites and abundant in pegmatites; it is colorless, whitish, or pale brown, and the crystals are tabular sheets with prominent base and hexagonal or rhomboid outline; hardness is 2-2.5 on Mohs scale, and specific gravity is 2.7-3.1. Also known as common mica; mirror stone; moscovite; Muscovy glass; potash mica; white mica.


1. a native or inhabitant of Moscow
2. an archaic word for Russian
References in periodicals archive ?
Magmatic muscovite from granites is generally characterized by relatively high contents of Fe, Mg and also Ti (Miller et al.
Muscovite is used for a huge range of mica products such as cosmetics, auto paint, plastic filler, coating for shingles and roofing, and a number of construction applications.
Storms and torrential rain blew down the Muscovite tents and turned their camp to mud.
Typically yellow Muscovite render is used on the residential blocks, joining a diverse palette of materials used with great finesse.
Ground muscovite mica products produced by dry grinding, wet grinding, and micronizing techniques.
Muscovite high school students from 12 schools were sampled in spring 1994.
Modern scholarship has abandoned the extremes of this political interpretation of Muscovite culture.
Initial cracks on the surface of concrete due to expansion of these layered silicate minerals can provide channel paths for more water circulation in the concrete which can further bulge muscovite biotite chlorite and alkali silica gel plus enhance the alteration of alteration sensitive minerals.
The second one corresponds to greenschist facies (Figure 30, represented by chlorite + muscovite + epidotesr-plagioclase (albite) + quartz + actinolite.
The sand grains with muscovite flakes, feldspar grains and rock fragments were possibly derived from Sargodha Karana Highs of Indian shield.
According to the Herald Sun, Nikolai Shadrin was arrested after police located the apartment where he killed 40-year-old Muscovite Ilya Yegorov in early May.