phlogopite

English Thesaurus

1. a brown form of mica consisting of hydrous silicate of potassium and magnesium and aluminum (noun.substance)

hypernym	:	isinglass, mica,
definition	:	any of various minerals consisting of hydrous silicates of aluminum or potassium etc. that crystallize in forms that allow perfect cleavage into very thin leaves; used as dielectrics because of their resistance to electricity (noun.substance)