Crystal system:
~Trigonal. but this
is disputed.
Crystal habit: Unique
cylindrical crystals that look
like tubes or rolls of metallic
cloth. but occasionally found
in masses.
Colour: Black to grey.
Lustre: Metallic.
Streak: Black.
Hardness: 2.5.
Cleavage: None.
Fracture: Conchoidal.
Specific gravity: 5.5.
Notable locations: Only
found at Potosi and Mina
Santa Cruz (Poopo) in Bolivia
and in a few tin sulphide ores.