Tenacity
-
Slightly sectile
Solubility
-
1.04 x 10−25 g per 100 ml water (Ksp at 25°C = 2 x 10−32)
Durability
-
-
Specific Gravity
3.26-3.362
1
7.18
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Fracture
Conchoidal
Uneven
Cleavage
Good on {100}
Prismatic {10 1 0}, perfect
Mohs Hardness
6.5-72-2.5
2
10
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Chemical Composition
(Ca,Fe,Mn,Mg) 3Al 2BSi 4O 15(OH)Walter Schumann , Gemstones of the world (2001) More from other references
HgSMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references