Biotite

Mineral name- Biotite Magnetic- No Streak- Gray Cleavage- Yes (001) Fracture- Yes Breaks in uneven surfaces. Radioactivity- Yes Hardness scale- 3 Color- Dark brown, Greenish brown, Blackish brown, and Yellow white. Non-Metallic- Pearly Luster

http://upload.wikimedia.org/wikipedia/commons/1/1d/Biotite.jpg