Definitions for "Biotite"
Keywords:  mica, magnesium, alsi, igneous, iron
Mica containing iron and magnesia, generally of a black or dark green color; -- a common constituent of crystalline rocks. See Mica.
A species of mica, generally black or dark green, forming a common constituent of crystalline rocks.
black to brownish-black mica.
Keywords:  definition, need
NEED A DEFINITION.