Tenacity
-
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
2.50-2.803.50-3.60
1
7.18
👆🏻
Fracture
-
Uneven
Cleavage
Perfect
Good on {110}, (110) ^ (1 1 0) ≈87°; parting on {100}
Mohs Hardness
5-6.56
2
10
👆🏻
Chemical Composition
Na 4(Al,Si) 12O 24Cl to Ca 4(Si,Al) 12O 24(CO 3,SO 4)Arthur Thomas , Gemstones (2009)
(Na,Fe,Ca)Si 2O 6Ulrich Henn and Claudio C.