Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.1-3.23.31
1
7.18
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Fracture
-
-
Cleavage
Vitreous, pearly on cleavage
Indiscernible
Mohs Hardness
3-4-9999
2
10
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Chemical Composition
(Fe2+ ,Mg,Mn2+ ) 3(PO 4) 2 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
NaFe 3+ 3 Al 6 (BO 3 ) 3 Si 6 O 18 (O,F,OH) 4 Anthony et al, Handbook of mineralogy (2001)