mineral

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Hardness: 2-2.5 on Mohs scale; Color: Colorless, silvery-white, or tan; Luster: Pearly to metallic; Crystal Structure: Monoclinic; Cleavage: Perfect basal cleavage producing thin, flexible sheets; Specific Gravity: 2.8-2.9.

Hardness: 2-2
Color: Colorless, silvery-white, or tan
Luster: Pearly to metallic

Identified July 12, 2026More mineral →

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Physical properties

Formation & geological history

Formed primarily in metamorphic rocks like schists and gneisses, as well as in igneous rocks such as granite and pegmatites. It forms through the metamorphism of clay-rich sediments or the cooling of silica-rich magma fragments.

Uses & applications

Used as an electrical insulator in electronics, as a filler in paints and plastics, and as a glittering agent in makeup (lipstick, eyeshadow) and automotive paints.

Geological facts

Historically called 'Muscovy glass' because it was used in Russia as a cheaper, more durable alternative to glass for windows. Its sheets are highly heat-resistant and do not conduct electricity.

Field identification & locations

Identified in the field by its distinct silvery 'glitter,' pearly luster, and 'peeling' behavior where it flakes off into thin, transparent, elastic plates. Commonly found in micaceous schists and granite outcroppings.