Tenacity
Brittle
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.50-3.603.26-3.36
1
7.18
👆🏻
Fracture
Uneven
Conchoidal
Cleavage
Good on {110}, (110) ^ (1 1 0) ≈87°; parting on {100}
Good on {100}
Mohs Hardness
66.5-7
2
10
👆🏻
Chemical Composition
(Na,Fe,Ca)Si 2O 6Ulrich Henn and Claudio C.
(Ca,Fe,Mn,Mg) 3Al 2BSi 4O 15(OH)Walter Schumann , Gemstones of the world (2001) More from other references