Crystals are nearly opaque being transparent in thin splinters. Crystal Habits include stubby prismatic crystals with complexly faceted or rounded terminations. Also very flat tabular crystals sometimes aggregated together in parallel or nearly parallel groups. Can also be granular and massive. Cleavage is good in one direction.
Fracture is subconchoidal.
Streak is brownish-red to black. Associated Minerals include albite , spodumene , cassiterite , microcline , lepidolite , apatite , beryl , microlite , tourmalines and amblygonite. Best Field Indicators are crystal habit, streak, associations and specific gravity.