Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
2.90-3.102.60-2.64
1
7.18
👆🏻
Fracture
Uneven, Conchoidal
Uneven, Splintery, Conchoidal
Cleavage
Poor/indistinct on {1120} and {1011}
Absent
Mohs Hardness
76.5-7
2
10
👆🏻
Chemical Composition
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
SiO 2Arthur Thomas , Gemstones (2009)