Class : Silicates
    Subclass : Phyllosilicates
    Crystal system : Monoclinic
    Chemistry : KMg₃Si₃AlO₁₀(F,OH)₂
    Rarity : Common

Phlogopite belongs to the micas group and constitutes the magnesium pole of the solid solution that it forms with biotite. It can be rich in fluorine (up to 6%) or manganese. It is a mica common in metasomatic contact deposits (cipolins and dolomitic marbles) and in granitic pegmatites; it is also the mica of kimberlites where it is formed at the expense of pyroxenes. Its name comes from the Greek phlogopos (similar to flame), in reference to the reddish color of certain specimens. Phlogopite frequently occurs in enormous lamellar crystals resembling short pseudohexagonal prisms or truncated pyramids, frequently twinned, and also in golden lamellae. Translucent, its color is brown to reddish-brown, rarely golden yellow-brown to gray. Like all micas, phlogopite has perfect cleavage according to {001}. It is much less used than muscovite because of its iron content which makes it an easily degradable material. It is marginally used as an insulator in the electrical and thermal industry.

Main photo : Phlogopite from Betroka District, Anosy Region, Tuléar Province, Madagascar

Twins are common in this mineral species.

No fakes listed for this mineral species.