Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
2.50-2.803.43-3.44
1
7.18
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Fracture
-
-
Cleavage
Perfect
None Observed
Mohs Hardness
5-6.56.5-7
2
10
👆🏻
Chemical Composition
Na 4(Al,Si) 12O 24Cl to Ca 4(Si,Al) 12O 24(CO 3,SO 4)Arthur Thomas , Gemstones (2009)
Ca 2(Mg,Al) 6(Si,Al,B) 6O 20Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references