1 Physical Properties
1.1 Tenacity
1.2 Solubility
Not Available
Not Available
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001), Brittle
Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009)
1.6 Cleavage
Distinct on {11 2 0}, imperfect on {10 1 1}
Good in one direction
1.7 Mohs Hardness
1.8 Chemical Composition
Be 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Fe,Mn)Ta 2O 6Walter Schumann , Gemstones of the world (2001) More from other references