Tenacity
Brittle
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
2.60-2.905.00-5.30
1
7.18
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Fracture
Uneven, Conchoidal, Irregular
Uneven, ConchoidalWalter Schumann, Conchoidal
Cleavage
Imperfect on {0001}
None, may show partings on {0001} and {10 1 1}
Mohs Hardness
7.5-86
2
10
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Chemical Composition
Be3Al2Si6O18
Fe 2O 3Arthur Thomas , Gemstones (2009)