Muscovite schist: A specimen of muscovite schist. Muscovite is characteristic of granite and granite pegmatites, associated with quartz and feldspars. The auto industry in the United States uses ground mica to improve the performance of plastic parts. (Fisher, 1965). Sheet size is 3 inches x 4 inches. The best way to learn about minerals is to study with a collection of small specimens that you can handle, examine, and observe their properties. ADAMS COUNTY: Muscovite in common in quartzite and granitic rocks at Hamilton Mounds, Sec. Used in the manufacturing of paint, joint compound, plastics rubber, asphalt roofing, cosmetics, drilling mud. The ability of muscovite to split into thin transparent sheets - sometimes up to several feet across - gave it an early use as window panes. isolated grains in schist and gneiss, or it can be abundant enough that the rocks are called "mica schist" or "micaceous gneiss.". Especially characteristic of pegmatite dikes, and found lining cavities in granites, where it has evidently been formed by the action of mineralizing vapors during the last stages of the formation of the rock. Muscovite typically occurs in metamorphic rocks, particularly gneisses and schists, where it forms crystals and plates. 5 T.23N. Muscovite with pen for scale. Acrylic, fiberglass, nylatron, nylon, polyester, styrene, vinyl-PVC, and vulcanized fibers are all finding use and SE NE sec. CHIPPEWA COUNTY: Occurs along bedding planes and in argillites interbedded with the Flambeau quartzite, as exposed in SE sec. Facebook Muscovite is found all over the world but the largest and most important deposits are found in Russia, Pakistan, India, and Brazil. Publications. About 50,000 tons were produced in the United States Scrap, flake, and ground muscovite are used as fillers and extenders in a variety of paints, surface treatments, Muscovite is a common rock-forming mineral. and nail polish. 11 T.32N. Maps/Data In igneous rocks, it is a primary mineral that is especially common in granitic rocks. Muscovite, one of the most common forms of mica mineral. (Greenberg et al., 1986) Buchholz (1999b) reports abundant pale green muscovite locally in a pocket in a pegmatite in one of the “rotten granite” quarries south of Rib Mountain. Thin sheets often have a slight tint of brown, green, yellow, or rose. FOREST COUNTY: Sericite is abundant in the altered volcanic rocks of the Crandon massive sulfide deposit near Little Sand Lake. Specimen and photo by Arkenstone / www.iRocks.com. In pegmatites, it is often found in immense sheets that are commercially valuable. Muscovite Crystallography: Axial Ratios: a:b:c =0.5747:1:2.2203 : Cell Dimensions: a = 5.19, b = 9.03, c = 20.05, Z = 4; beta = 95.5° V = 935.33 Den(Calc)= 2.83 18 T.33N. equipment. In igneous rocks, it is a primary mineral that is WOOD COUNTY: Tiny euhedral crystals of muscovite occur in pockets with fluorite, calcite and K feldspar at the Frederick Schill Quarry, near Vesper on the E side of HWy. R.4W., N of the South Fork of the Eau Claire River (Myers, 1977; WGNHS outcrop description). 5 T.23N. Ground muscovite: Photograph of ground muscovite from Mt. The use of ground mica is mainly determined by activity levels of the construction and auto industries. R.20E., near Middle Islet. WAUPACA COUNTY: Muscovite occurs in the granite quarried in Waupaca (SW sec. Muscovite is found in igneous, metamorphic, and sedimentary rocks. 1, SW sec. and roofing. Muscovite: Muscovite from Stoneham, Maine. CLARK COUNTY: Found in felsic phyllonite with quartz and K feldspar exposed below the Mead Dam (SE sec. (Buchholz,1997). cesium. Pinterest, Website or The mica does not absorb the asphalt and stands up well to weathering. Muscovite mica Muscovite in economic quantities is confined to coarse-grained granite pegmatite dykes consisting largely of quartz, feldspar and mica. Characteristic of deep-seated siliceous igneous rocks as granite and syenite. In plastics, particles R.2E. Muscovite and Fuchsite. R.6E.) and in the SE SW sec. ), Muscovite. as sheet mica substitutes . Description: Muscovite is a common mica, forming silvery to pale-colored flakes most commonly schists and granite pegmatites. Muscovite: Muscovite from Mitchell County, North Carolina. Muscovite is the most common mica, found in granites, pegmatites, gneisses, and schists, and as a contact metamorphic rock or as a secondary mineral resulting from the alteration of topaz, feldspar, kyanite, etc. (Greenberg et al., 1976). shearing of the finished surface; reduces water penetration and weathering, and brightens the tone of colored pigments. north of Willard (Myers, 1977; WGNHS outcrop descriptions). From the mineral collection of Brigham Young University Department of Geology, Provo, Utah, Mineral Specimens 801. Inexpensive mineral collections are available in the Geology.com Store. (608) 262-1705 - Green form of Muscovite mica in small dense flake groups found in Mariposa (and Tuolumne) County, California. This particular mineral was found in Finland. It is quickly transformed into clay minerals. R.4E. Ground mica is an additive to drilling mud that helps to seal porous sections of the drill hole to reduce circulation loss. MARATHON COUNTY: Muscovite is a common constituent of the granites of the Wausau Complex (Falster, 1987) Ninemile complex near Wausau (Patton et al., 1989) and Mosinee (Anderson et al., 1980). The flat mica particles coat the Muscovite can occur as The transparent nature of muscovite is clearly seen in this photo. The dykes are of acidic igneous origin, and the minerals probably crystallized directly from magma. 18 T.22N. The platy grains of mica act as an antisticking agent. Ground mica is used as a pigment extender in paint. In the 1700s it was mined for this use from pegmatites in the area around Moscow, Russia. optical filters, pyrometers, retardation plates in helium-neon lasers, missile systems components, medical electronics, R.12E.) Muscovite can form during the regional metamorphism of argillaceous rocks. R.17E. and reduce dielectric strength. Mica with inclusions: Sheets of mica with inclusions are often sold as low-quality windows for woodstoves, ovens, and furnaces at a reduced price.