mineral

Muscovite Mica

Muscovite: KAl2(AlSi3O10)(OH)2

Hardness: 2.5-3 (Mohs). Color: Silvery-white, pale yellow, or green. Luster: Pearly to metallic. Crystal structure: Monoclinic with perfect basal cleavage, allowing it to split into thin, flexible transparent sheets.

Hardness: 2
Color: Silvery-white, pale yellow, or green
Luster: Pearly to metallic

Identified April 12, 2026More mineral →

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Physical properties

Formation & geological history

Formed in igneous environments (granites/pegmatites) or metamorphic environments (schists/gneiss). It is a rock-forming mineral resulting from the cooling of magma or the metamorphism of clay-rich sediments.

Uses & applications

Used as an electrical insulator in high-voltage equipment, as a filler in paints and plastics, and in cosmetics (lipstick/eyeshadow) for its shimmer. Historically used as window panes ('Muscovy glass').

Geological facts

In early Russia, it was nicknamed 'Muscovy glass' because big sheets of it were used as a cheaper, more durable alternative to glass for windows.

Field identification & locations

Identify in the field by its distinct ability to peel away in paper-thin, transparent sheets. It is very soft and can be scratched by a fingernail. Commonly found in areas with granite outcrops or mountain ranges with high-grade metamorphic rocks.