Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.26-3.364.95-5.0
1
7.18
👆🏻
Fracture
Conchoidal
Uneven
Cleavage
Good on {100}
Imperfect to indistinct on {10 1 0}, parting on {0001}
Mohs Hardness
6.5-74-5
2
10
👆🏻
Chemical Composition
(Ca,Fe,Mn,Mg) 3Al 2BSi 4O 15(OH)Walter Schumann , Gemstones of the world (2001) More from other references
(Ce,La)(CO 3)FMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references