Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
(Na,Ca)4-8Al6Si6(O,S)24(SO4,Cl)1-2
Subconchoidal, Uneven, Conchoidal, Irregular
{100} imperfect, {110} indistinct; partings on {111} or {011}
SnO 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references