Tenacity
-
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
3.34-3.442.33-2.37
1
7.18
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Fracture
Conchoidal
ConchoidalWalter Schumann
Cleavage
{111} Indistinct, {111} Indistinct, {111} Indistinct
Perfect on {010}, good on {100}
Mohs Hardness
8-8.57.5
2
10
👆🏻
Chemical Composition
(K,Cs)Al 4Be 4(B,Be) 12O 28Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Be 2BO 3(OH)Ulrich Henn and Claudio C.