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
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references, Fibrous
1.6 Cleavage
Imperfect on {110}
{001} perfect and {100} imperfect
1.7 Mohs Hardness
1.8 Chemical Composition
(Na,Ca) 8Al 6Si 6O 24(SO 4,S,Cl) 2Ulrich Henn and Claudio C.
CaAl 2(Fe3+ ,Al)Si 3O 12(OH)Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references