Fibrous, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references
Conchoidal, Brittle, Conchoidal, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Distinct on {100}, poor on {110}; parting on {001}
Rare tabular and prismatic crystals. Usually occurs as fibrous, parallel veins that break off into cleavage fragments.