Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
2.40-2.423.76-3.77
1
7.18
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Fracture
-
-
Cleavage
{010} Perfect, {001} Distinct
{110} Perfect, {110} Perfect
Mohs Hardness
4.55-6
2
10
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Chemical Composition
Ca 2B 6O 11 · 5H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Fe,Mn) 7Si 7O 21Ulrich Henn and Claudio C.