1 Physical Properties
1.1 Tenacity
1.2 Solubility
Gelatinises in acids
Dilute acid
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Uneven, Conchoidal, Brittle
Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
1.6 Cleavage
Distinct on {110}
Distinct on {010}, imperfect {110} and {011}
1.7 Mohs Hardness
1.8 Chemical Composition
(Na,Ca)4-8Al6Si6(O,S)24(SO4,Cl)1-2
CaCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references