Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.355-3.4333.95-4.10
1
7.18
👆🏻
Fracture
Uneven
Uneven
Cleavage
{???} Good, {???} Good
{110} Perfect, {110} Perfect, {110} Perfect
Mohs Hardness
-99993.5-4
2
10
👆🏻
Chemical Composition
(Ca,Mn2+ ,Fe2+ ) 3Al 2BSi 4O 15(OH)Anthony et al , Handbook of mineralogy (2001)
(Zn,Fe)SMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references