Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
2.55-2.652.9
1
7.18
👆🏻
Fracture
Conchoidal
Conchoidal
Cleavage
Perfect {10 1 0}
{???} Indistinct
Mohs Hardness
5.5-64.5
2
10
👆🏻
Chemical Composition
(Na,Ca,K) 8(Si,Al) 12O 24(SO 4,Cl,CO 3) 3(H 2O)Arthur Thomas , Gemstones (2009)
(Zn,Cu)Al 6(PO 4) 4(OH) 8 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)