Tenacity
-
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
2.60-3.025.00-5.30
1
7.18
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Fracture
-
Uneven, ConchoidalWalter Schumann, Conchoidal
Cleavage
Perfect
None, may show partings on {0001} and {10 1 1}
Mohs Hardness
-99996
2
10
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Chemical Composition
(Mg,Fe2+ ) 5Al(Si 3Al)O 10(OH) 8Anthony et al , Handbook of mineralogy (2001)
Fe 2O 3Arthur Thomas , Gemstones (2009)