Tenacity
Brittle
-
Solubility
insoluble
-
Durability
-
-
Specific Gravity
2.402.60-3.02
1
7.18
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Fracture
Subconchoidal, ConchoidalWalter Schumann, Conchoidal
-
Cleavage
Perfect on {001}, poor on {201} with 38.5° angle between the two
Perfect
Mohs Hardness
6-6.5-9999
2
10
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Chemical Composition
LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Mg,Fe2+ ) 5Al(Si 3Al)O 10(OH) 8Anthony et al , Handbook of mineralogy (2001)