Tenacity
Brittle
-
Solubility
-
-
Durability
-
-
Specific Gravity
5.50-5.902.90-3.10
1
7.18
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Fracture
Conchoidal
Uneven, Conchoidal
Cleavage
On {10 1 0}, perfect; parting on {000 1 }
Poor/indistinct on {1120} and {1011}
Mohs Hardness
47
2
10
👆🏻
Chemical Composition
(Zn,Mn2+ )OMichael OâDonoghue , Gems, Sixth Edition (2006)
Na(Li 1.5Al 1.5)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012) More from other references