Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/47445767@N05">James St. John</a> (CC BY 2.0)
monocliniccommonSilicates
Muscovite
KAl2(AlSi3O10)(OH)2
Muscovite appears as clearish-silvery, flexible, and platy crystals, often forming 'books' or sheets within the host rock.
Muscovite Physical Properties
Mohs Hardness
2.5Crystal System
monoclinicLuster
vitreousStreak Color
whiteCleavage
perfect basal (one direction)Fracture
unevenSpecific Gravity
2.8Colors
colorless, white, silver, pale yellow, pale brown, pale greenTransparency
transparent to translucentType Locality
Ruggles Pegmatite Mine, New Hampshire, USAMineral Group
SilicatesUses
electrical insulator, filler in paints and plastics, cosmetics, collector specimensAssociated Minerals
biotite, quartz, feldspar, tourmaline, berylRarity
commonGeological Context
Muscovite is a common rock-forming mineral found in igneous rocks, particularly pegmatites and granites, and in metamorphic rocks like schists and gneisses, forming under various pressure and temperature conditions.
