Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.26-3.413.03-3.18
1
7.18
👆🏻
Fracture
Fibrous, ConchoidalWalter Schumann
Uneven, Irregular, Conchoidal
Cleavage
Distinct on {100}, poor on {110}; parting on {001}
{???} Indistinct
Mohs Hardness
7-8.57-7.5
2
10
👆🏻
Chemical Composition
AlAl6O3BSi3O18
Na(Mg 3)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)