mineral

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(F,OH)2)

Hardness: 2.0–2.5 Mohs; Color: Colorless, silvery-white, or brownish; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Perfect basal cleavage (easily splits into thin sheets)

Hardness: 2
Color: Colorless, silvery-white, or brownish
Luster: Vitreous to pearly

Identified May 10, 2026More mineral →

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Physical properties

Hardness: 2.0–2.5 Mohs; Color: Colorless, silvery-white, or brownish; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Perfect basal cleavage (easily splits into thin sheets)

Formation & geological history

Commonly formed in metamorphic rocks like schist and gneiss, or in igneous rocks like peraluminous granites and pegmatites through crystallization of silica-rich melts.

Uses & applications

Used as an electrical insulator in electronics, in joint compound for drywall, as a pearlescent pigment in cosmetics (glitter), and as a ground-up additive in paint and rubber.

Geological facts

The name 'Muscovite' comes from 'Muscovy-glass', as the mineral was used in medieval Russia as a cheaper alternative to glass for windows. It is the most common form of mica.

Field identification & locations

Identified in the field by its ability to be peeled into thin, flexible, transparent 'books' or sheets and its distinct pearly or silvery luster. Often found in sandy soils or near granite outcrops.