Phlogopite: A yellow to brown, magnesiumrich mica mineral
Phlogopite is an aluminosilicate mineral of potassium and magnesium, and a member of the mica group. Phlogopite usually ranges in color from yellow to brown to reddish brown. Its color can be helpful in distinguishing it from other mica minerals. Phlogopite and muscovite are the only two mica minerals that are used commercially. Geologic Occurrence