Biotite

Biotite
Biotite mainly occurs in metamorphic rocks, granite and other rocks. The color of
biotite is from black to brown or green, with glass luster. The shape is plate
and column. In recent years, biotite has been widely used in stone paint and
other decorative coatings.  
 
The single crystal of wancheng biotite is short columnar and plate-shaped, with a
hexagonal cross-section and scaly aggregate. Brown or black. The color becomes
darker with the increase of iron content. Other optical and mechanical properties
are similar to those of muscovite, with a relative density of 2.7-3.3.

Click to Enlarge