Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.26-3.363.07-3.13
1
7.18
👆🏻
Fracture
Conchoidal
Conchoidal, Uneven
Cleavage
Good on {100}
{100} Perfect, {010} Distinct, {102} Distinct
Mohs Hardness
6.5-73-3.5
2
10
👆🏻
Chemical Composition
(Ca,Fe,Mn,Mg) 3Al 2BSi 4O 15(OH)Walter Schumann , Gemstones of the world (2001) More from other references
Zn 2(Fe2+ ,Mn2+ )(PO 4) 2 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references