One cleavage direction. Weathering end product(s): Loss of Fe, Mg. Occurrence: Igneous, sediments, metamorphic. Rusty discoloration by loss of Fe. Property values are typical of naturally occurring Biotite K (Mg,Fe)3-(AlSi3O10)(OH)2. Actual property values will vary from sample to sample. |
Biotite K (Mg,Fe)3-(AlSi3O10)(OH)2 |