mineral

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Hardness: 2.0-2.5 on Mohs scale; Color: Colorless, silvery-gray, or light green; Luster: Pearly to Vitreous; Crystal Structure: Monoclinic; Cleavage: Perfect basal (peels into thin flexible sheets); Specific Gravity: 2.76-3.00

Hardness: 2
Color: Colorless, silvery-gray, or light green
Luster: Pearly to Vitreous

Identified May 7, 2026More mineral →

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Physical properties

Formation & geological history

Forms primarily in igneous rocks like pegmatites and granites, as well as metamorphic rocks like schists and phyllites through regional metamorphism. It can also be found in sedimentary rocks as detrital flakes.

Uses & applications

Used as an electrical insulator in electronics, as a filler in paints and plastics, and in cosmetics (especially eyeshadow and lip gloss) for its shimmer/glitter effect.

Geological facts

The name 'Muscovite' comes from 'Muscovy-glass', as large sheets of this mineral were once used as a cheaper alternative to glass for windows in Russia. It is highly resistant to heat and electricity.

Field identification & locations

Identify by its 'books' of thin, transparent, flexible layers that can be split with a fingernail. Found globally, specifically in areas with exposed metamorphic bedrock or pegmatite veins. It is a common component of many granites.