Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.1-3.22.50-2.80
1
7.18
👆🏻
Fracture
-
-
Cleavage
Vitreous, pearly on cleavage
Perfect
Mohs Hardness
3-45-6.5
2
10
👆🏻
Chemical Composition
(Fe2+ ,Mg,Mn2+ ) 3(PO 4) 2 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Na 4(Al,Si) 12O 24Cl to Ca 4(Si,Al) 12O 24(CO 3,SO 4)Arthur Thomas , Gemstones (2009)