Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
2.55-2.65-9999
1
7.18
👆🏻
Fracture
Conchoidal
Conchoidal
Cleavage
Perfect {10 1 0}
None
Mohs Hardness
5.5-67-7.5
2
10
👆🏻
Chemical Composition
(Na,Ca,K) 8(Si,Al) 12O 24(SO 4,Cl,CO 3) 3(H 2O)Arthur Thomas , Gemstones (2009)
Al 4(Ta,Nb) 3(O,OH,F) 14Ulrich Henn and Claudio C.