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
Sub-Conchoidal, Irregular/uneven, Sub-Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
1.6 Cleavage
Distinct on {110}
[100] Perfect, [110] Good, [011] Distinct
1.7 Mohs Hardness
1.8 Chemical Composition
(Na,Ca)4-8Al6Si6(O,S)24(SO4,Cl)1-2
(Li,Na)Al(PO 4)(F,OH)Michael OâDonoghue , Gems, Sixth edition (2006) More from other references