1 Physical Properties
1.1 Tenacity
Not Available
Very brittle
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
2.55-2.653.30-3.40
1
7.18
1.5 Fracture
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle, Conchoidal, Brittle
Conchoidal, Brittle, Conchoidal
1.6 Cleavage
Perfect {10 1 0}
{010} perfect, {110} distinct, {100} in traces
1.7 Mohs Hardness
1.8 Chemical Composition
(Na,Ca,K) 8(Si,Al) 12O 24(SO 4,Cl,CO 3) 3(H 2O)Arthur Thomas , Gemstones (2009)
AlO(OH)Walter Schumann , Gemstones of the world (2001) More from other references