Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
1.98-2.502.70-2.75
1
7.18
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Fracture
ConchoidalWalter Schumann
Conchoidal
Cleavage
None
From the Greek for luster, for its pearly luster on the cleavage.
Mohs Hardness
5.5-6.54.5-5
2
10
👆🏻
Chemical Composition
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
Al 2(PO 4)(OH) 3Michael OâDonoghue , Gems, Sixth Edition (2006)