Tenacity
Brittle
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.7-3.83.05-3.08
1
7.18
👆🏻
Fracture
Subconchoidal, Conchoidal
Subconchoidal, Uneven, Conchoidal
Cleavage
Distinct on {010}
Poor on {100}
Mohs Hardness
7-7.55
2
10
👆🏻
Chemical Composition
(Fe,Mg,Zn) 2Al 9(Si,Al) 4O 22(OH) 2Ulrich Henn and Claudio C.
Mn2+ Al(PO 4)(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)