Tenacity
-
Brittle
Solubility
-
Soluble
Durability
-
-
Specific Gravity
3.03-3.183.25-3.35
1
7.18
👆🏻
Fracture
Uneven, Irregular, Conchoidal
Conchoidal, ConchoidalWalter Schumann
Cleavage
{???} Indistinct
Perfect in three directions
Mohs Hardness
7-7.55
2
10
👆🏻
Chemical Composition
Na(Mg 3)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)
CuSiO 2(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references