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
Gems, Sixth Edition (2006), Gems, Sixth Edition (2006)
1.6 Cleavage
Imperfect on {110}
Not Available
1.8 Mohs Hardness
1.13 Chemical Composition
(Na,Ca) 8Al 6Si 6O 24(SO 4,S,Cl) 2Ulrich Henn and Claudio C.
SiO 2Michael OâDonoghue , Gems, Sixth Edition (2006)