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
Irregular/uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
1.6 Cleavage
Distinct on {110}
Perfect on {10 1 0}, poor on {0001}
1.7 Mohs Hardness
1.8 Chemical Composition
(Na,Ca)4-8Al6Si6(O,S)24(SO4,Cl)1-2
Na 2Ca 2Al 6Si 6O 24(CO 3) 2Walter Schumann , Gemstones of the world (2001) More from other references