Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.355-3.4333.07-3.13
1
7.18
👆🏻
Fracture
Uneven
Conchoidal, Uneven
Cleavage
{???} Good, {???} Good
{100} Perfect, {010} Distinct, {102} Distinct
Mohs Hardness
-99993-3.5
2
10
👆🏻
Chemical Composition
(Ca,Mn2+ ,Fe2+ ) 3Al 2BSi 4O 15(OH)Anthony et al , Handbook of mineralogy (2001)
Zn 2(Fe2+ ,Mn2+ )(PO 4) 2 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references