Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
(Na,Ca) 8Al 6Si 6O 24(SO 4,S,Cl) 2Ulrich Henn and Claudio C.
Subconchoidal, Uneven, Conchoidal, Irregular
{100} imperfect, {110} indistinct; partings on {111} or {011}
SnO 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references