Tenacity
-
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
2.50-2.804.32-4.48
1
7.18
👆🏻
Fracture
-
Uneven, Subconchoidal, Conchoidal
Cleavage
Perfect
{101}, good; {010}, poor
Mohs Hardness
5-6.53.5
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)
Zn 2(AsO 4)(OH)Michael OâDonoghue , Gems, Sixth edition (2006)