Tenacity
Brittle
Brittle
Solubility
Readily soluble in HF
Soluble
Durability
-
-
Specific Gravity
2.86-2.943.25-3.35
1
7.18
👆🏻
Fracture
Conchoidal, Uneven
Conchoidal, ConchoidalWalter Schumann
Cleavage
None observed
Perfect in three directions
Mohs Hardness
6.5-75
2
10
👆🏻
Chemical Composition
(Cs,Na)(AlSi 2O 6) · 0.5H 2OWalter Schumann , Gemstones of the world (2001) More from other references
CuSiO 2(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references