Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
1.98-2.502.25-2.40
1
7.18
👆🏻
Fracture
ConchoidalWalter Schumann
-
Cleavage
None
perfect on {010}; good on {100}
Mohs Hardness
5.5-6.55-5.5
2
10
👆🏻
Chemical Composition
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
NaCa 2Al 5Si 5O 20 · 6H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references