Physical Properties
Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
1.98-2.502.90-3.10
1
7.18
👆🏻
Fracture
Conchoidal
Uneven, Conchoidal
Cleavage
None
Poor/indistinct on {1120} and {1011}
Mohs Hardness
5.5-6.57
2
10
👆🏻
Chemical Composition
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
Na(Li 1.5Al 1.5)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012) More from other references