Tenacity
Brittle
Brittle
Solubility
-
Soluble
Durability
-
-
Specific Gravity
2.74-2.903.25-3.35
1
7.18
👆🏻
Fracture
Uneven, Splintery
Conchoidal, ConchoidalWalter Schumann
Cleavage
Perfect on {100} and {001}
Perfect in three directions
Mohs Hardness
4.5-55
2
10
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Chemical Composition
Ca 2NaHSi 3O 9Ulrich Henn and Claudio C.
CuSiO 2(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references