Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Subconchoidal, Uneven, Conchoidal, Irregular
{100} imperfect, {110} indistinct; partings on {111} or {011}
SnO 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Mn2+ ,Fe2+ ,Mg)(Fe3+ ,Mn3+ ) 2O 4Anthony et al , Handbook of mineralogy (2001)