Tenacity
Brittle
-
Solubility
-
-
Durability
-
-
Specific Gravity
5.50-5.903.31
1
7.18
👆🏻
Fracture
Conchoidal
-
Cleavage
On {10 1 0}, perfect; parting on {000 1 }
Indiscernible
Mohs Hardness
4-9999
2
10
👆🏻
Chemical Composition
(Zn,Mn2+ )OMichael OâDonoghue , Gems, Sixth Edition (2006)
NaFe 3+ 3 Al 6 (BO 3 ) 3 Si 6 O 18 (O,F,OH) 4 Anthony et al, Handbook of mineralogy (2001)