mineral

Muscovite Mica

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

Hardness: 2-2.5 on the Mohs scale, Color: Silver, gray, yellow, brown, or green, Luster: Vitreous to pearly or metallic, Crystal Structure: Monoclinic, Cleavage: Perfect basal cleavage allowing it to split into extremely thin, flexible sheets, Specific Gravity: 2.76-3.0

Hardness: 2-2

Identified July 28, 2026More mineral →

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Physical properties

Formation & geological history

Forms in igneous rocks like granites and pegmatites, as well as metamorphic rocks like schists and gneisses, through the crystallization of silica- and potassium-rich magmas or through regional metamorphism.

Uses & applications

Used in electrical insulators, drywall joint compounds, paint fillers, cosmetics, and as a heat-resistant window material in traditional stoves.

Geological facts

Muscovite is the most common mineral of the mica family and was historically known as 'Muscovy glass' because it was used as a glass substitute in medieval Russia.

Field identification & locations

Easily identified in the field by its distinct sheet-like appearance, perfect basal cleavage into transparent or translucent flexible sheets, and pearly luster. Found worldwide in pegmatite veins and metamorphic terrains.