Tenacity
-
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
5.05-5.222.33-2.37
1
7.18
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Fracture
Uneven
ConchoidalWalter Schumann
Cleavage
None
Perfect on {010}, good on {100}
Mohs Hardness
5.5-67.5
2
10
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Chemical Composition
(Zn,Mn2+ ,Fe2+ )(Fe3+ ,Mn3+ ) 2O 4Anthony et al , Handbook of mineralogy (2001)
Be 2BO 3(OH)Ulrich Henn and Claudio C.