Biotite
Videos
Biotite is a common group of phyllosilicate minerals within the mica group, with the approximate chemical formula K3AlSi3O102. It is primarily a solid-solution series between the iron-endmember annite
Thin tabular biotite aggregate (Image width: 2.5 mm)
Flaky biotite sheets
Thick biotite sample featuring many sheets
Biotite crystal exhibiting pseudohexagonal shape
Mica
Videos
Micas are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into fragile elastic plates. This characteristic is described as p
Biotite
…Biotite is a common group of phyllosilicate minerals within the mica group, with the approximate chemical formula K(Mg,Fe)3AlSi3O10(F,OH)2. It is primarily a solid-solution series between the iron-endmember annite, and…
Mica
Sheets of mica
Photomicrographs of a thin section containing phlogopite. In cross-polarized light on the left, plane-polarized light on the right.
Dark mica from eastern Ontario