Definition: phlogopite

Source: WordNet (r) 1.7

phlogopite
     n : a brown form of mica consisting of hydrous silicate of
         potassium and magnesium and aluminum

Source: Webster's Revised Unabridged Dictionary (1913)

Mica \Mi"ca\, n. [L. mica crumb, grain, particle; cf. F. mica.]
   (Min.)
   The name of a group of minerals characterized by highly
   perfect cleavage, so that they readily separate into very
   thin leaves, more or less elastic. They differ widely in
   composition, and vary in color from pale brown or yellow to
   green or black. The transparent forms are used in lanterns,
   the doors of stoves, etc., being popularly called
   isinglass. Formerly called also cat-silver, and
   glimmer.

   Note: The important species of the mica group are:
         muscovite, common or potash mica, pale brown or
         green, often silvery, including damourite (also
         called hydromica); biotite, iron-magnesia mica,
         dark brown, green, or black; lepidomelane, iron,
         mica, black; phlogopite, magnesia mica, colorless,
         yellow, brown; lepidolite, lithia mica, rose-red,
         lilac. Mica (usually muscovite, also biotite) is an
         essential constituent of granite, gneiss, and mica
         slate; biotite is common in many eruptive rocks;
         phlogopite in crystalline limestone and serpentine.

   Mica diorite (Min.), an eruptive rock allied to diorite but
      containing mica (biotite) instead of hornblende.

   Mica powder, a kind of dynamite containing fine scales of
      mica.

   Mica schist, Mica slate (Geol.), a schistose rock,
      consisting of mica and quartz with, usually, some
      feldspar.

Phlogopite \Phlog"o*pite\, n. [Gr. ? firelike.] (Min.)
   A kind of mica having generally a peculiar bronze-red or
   copperlike color and a pearly luster. It is a silicate of
   aluminia, with magnesia, potash, and some fluorine. It is
   characteristic of crystalline limestone or dolomite and
   serpentine. See Mica.