1 Physical Properties
1.1 Tenacity
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Uneven, UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, Uneven, Gems, Sixth Edition (2006)
1.6 Cleavage
Imperfect on {110}
Perfect [001] good [010] poor [110]
1.7 Mohs Hardness
1.8 Chemical Composition
(Na,Ca) 8Al 6Si 6O 24(SO 4,S,Cl) 2Ulrich Henn and Claudio C.
CaAl 2Si 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)