A yellow to dark brown mica, K(Mg,Fe)3AlSi3O10(OH)2, used in insulation.
A mica mineral aided by the chemical formula KMg3AlSi3O10(F,OH)2, a simple potassium magnesium aluminosilicate, used as an insulator.
some sort of mica having generally a peculiar bronze-red or copperlike color and a pearly luster. It really is a silicate of aluminia, with magnesia, potash, and some fluorine. It's characteristic of crystalline limestone or dolomite and serpentine. See mica.
a type of magnesia mica (see mica, 1) commonly happening in crystalline limestone as well as in serpentine.
a brown kind of mica composed of hydrous silicate of potassium and magnesium and aluminum