Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Mn2+9(SiO 4) 4(OH,F) 2Anthony et al , Handbook of mineralogy (2001)
Subconchoidal, Uneven, Conchoidal, Irregular
{100} imperfect, {110} indistinct; partings on {111} or {011}
SnO 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references