[7] Muscovite has a Mohs hardness of 2–2.25 parallel to the [001] face, 4 perpendicular to the [001] and a specific gravity of 2.76–3.

Muscovite is the most common mica, found in granites, pegmatites, gneisses, and schists, and as a contact metamorphic rock or as a secondary mineral resulting from the alteration of topaz, feldspar, kyanite, etc.

The name muscovite comes from Muscovy-glass, a name given to the mineral in Elizabethan England due to its use in medieval Russia (Muscovy) as a cheaper alternative to glass in windows.

Pyrophyllite, and talc are softer than micas and have a greasy feel, while chlorite is green in color and its cleavage sheets are inelastic.

In other words, a crystal of muscovite consists of layers (TOT) bonded to each other by potassium cations (c).

[9] The formula for muscovite is typically given as KAl2(AlSi3O10)(OH)2, but it is common for small amounts of other elements to substitute for the main constituents.

Muscovite can be cleaved into very thin transparent sheets that can substitute for glass, particularly for high-temperature applications such as industrial furnace or oven windows.

It is also used in tire manufacture as a mold release agent, in drilling mud, and in various cosmetics for its luster.