1 Physical Properties
1.1 Tenacity
Not Available
Slightly sectile
1.2 Solubility
Not Available
1.04 x 10−25 g per 100 ml water (Ksp at 25°C = 2 x 10−32)
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Uneven, Uneven, Gemstones (2009), Brittle
1.6 Cleavage
{1011} Indistinct
Prismatic {10 1 0}, perfect
1.7 Mohs Hardness
1.8 Chemical Composition
Na(Fe2+3)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)
HgSMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references