Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.26-3.363.05-3.21
1
7.18
👆🏻
Fracture
Conchoidal
Uneven, Subconchoidal, Splintery
Cleavage
Good on {100}
Good on {110}, poor on {100}
Mohs Hardness
6.5-77.5
2
10
👆🏻
Chemical Composition
(Ca,Fe,Mn,Mg) 3Al 2BSi 4O 15(OH)Walter Schumann , Gemstones of the world (2001) More from other references
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references