Tenacity
-
-
Solubility
-
insoluble
Durability
-
-
Specific Gravity
3.26-3.412.36
1
7.18
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Fracture
Fibrous, ConchoidalWalter Schumann
Uneven, Subconchoidal, Fibrous
Cleavage
Distinct on {100}, poor on {110}; parting on {001}
[110] perfect, [101] good, [010] distinct
Mohs Hardness
7-8.53.5-4
2
10
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Chemical Composition
AlAl6O3BSi3O18
Al 3(PO 4) 2(OH,F) 3 · 5H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references