Muscovite

Description

Muscovite is an important rock-forming mineral present in igneous, metamorphic, and sedimentary rocks. It readily cleaves into thin transparent sheets. Muscovite sheets have a pearly to vitreous luster on their surface. If they are held up to the light, they are transparent and nearly colorless, but most have a slight brown, yellow, green, or rose-color tint. The ability of muscovite to split into thin transparent sheets gave it an early use as window panes. Sheet muscovite is an excellent insulator, and that makes it suitable for manufacturing specialized parts for electrical equipment. Scrap, flake, and ground muscovite are used as fillers and extenders in a variety of paints, surface treatments, and manufactured products. The pearlescent luster of muscovite makes it an important ingredient that adds "glitter" to paints, ceramic glazes, and cosmetics. https://www.mindat.org/min-2815.html https://geology.com/minerals/muscovite.shtml