About Biotite
A common rock-forming phyllosilicate mineral, part of the mica group, typically black or dark brown. It's a grounding stone that aids in clear perception, organized thought, and releasing unwanted energies.
Primary Hues
Black, Dark Brown, Dark Green, often forms platy sheets
Geological & Scientific Details
Biotite is classified as a phyllosilicate minerals, mica group, biotite subgroup mineral which typically crystallizes in the monoclinic system. Its chemical formula is K(Mg,Fe)3(AlSi3O10)(F,OH)2. Common crystal habits include massive to platy.
Key Geological Properties:
- Mineral Category: Phyllosilicate minerals, mica group, biotite subgroup
- Chemical Formula: K(Mg,Fe)3(AlSi3O10)(F,OH)2
- IMA Symbol: Bt[1]
- Crystal System: Monoclinic
- Predominant Geological Color: Dark brown, greenish-brown, blackish-brown, yellow
- Crystal Habit: Massive to platy
- Twinning: Common on the [310], less common on the {001}
- Cleavage: Perfect on the {001}
- Luster: Vitreous to pearly
- Streak: White
- Diaphaneity: Transparent to translucent to opaque
Associated Minerals
- Mica
- Muscovite
- Phlogopite
- Lepidolite
- Feldspar
- Quartz
- Hornblende