Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.2-3.42.90-3.10
1
7.18
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Fracture
Uneven
Splintery, Granular
Cleavage
Perfect on [001] imperfect on [100]
None
Mohs Hardness
36-6.5
2
10
👆🏻
Chemical Composition
(K,Na) 3(Fe2+ ,Mn) 7Ti 2Si 8O 24(O,OH) 7Anthony et al , Handbook of mineralogy (2001)
Ca 2(Mg,Fe) 5(OH) 2Walter Schumann , Gemstones of the world (2001) More from other references