Tenacity
Brittle
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.69-3.813.76-3.77
1
7.18
👆🏻
Fracture
Uneven, Conchoidal to uneven, ConchoidalWalter Schumann
-
Cleavage
Distinct on {110}, imperfect on {010}, poor on {001}
{110} Perfect, {110} Perfect
Mohs Hardness
8.55-6
2
10
👆🏻
Chemical Composition
BeAl 2 O 4
(Fe,Mn) 7Si 7O 21Ulrich Henn and Claudio C.