Mineral Home | Alphabetical | Hardness | Cleavage | Luster | Key>glass | Key<glass
Igneous Home | Classification | Bowen's Reaction Series | Keys | Extrusive/Intrusive | Tectonics | Self Tests

    Sample in alkali granite
    Back to Muscovite #1
             Back to #3A
    Return to B.R.S.

A mica mineral. This sample shows well the basal cleavage and the tendency toward forming 6-sided crystals when the crystal can grow freely. This specimen comes from a pegmatite, a coarse grained granitic rock.
     Muscovite occurs occasionally in felsic igneous rocks. It is often recognized because light flashes sharply off its cleavages faces, almost like light off a mirror.

LSF Home | Geology Web Sites | Courses | JMU Geology
Last Update: 8/17/00

e-mail: (Fichtels@jmu.edu)