1 Physical Properties
1.1 Tenacity
1.2 Solubility
Gelatinises in acids
Not Available
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Uneven, Conchoidal, Brittle
Subconchoidal, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
1.6 Cleavage
Distinct on {110}
Perfect on [001] and [011]
1.7 Mohs Hardness
1.8 Chemical Composition
(Na,Ca)4-8Al6Si6(O,S)24(SO4,Cl)1-2
TiO 2Michael OâDonoghue , Gems, Sixth edition (2006) More from other references