Biotite (Mica)
$K(Mg,Fe)_3(Al,Fe)Si_3O_{10}(OH)$
Family
phyllosilicates
Crystal system
monoclinic
Color
black, light brown , bronze
Streak color
white to grey
Cleavage
1 perfect basal cleavage
Hardness
2,5 to 3,0
Density
2,8 to 3,2
Explanations: →
Here
List of minerals: →
Here
