Tenacity
Brittle
Not Available
Solubility
Not Available
Not Available
Durability
Not Available
Not Available
Specific Gravity
2.90-2.98
1.98-2.25
Fracture
Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001), Brittle
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references
Cleavage
Distinct on {11 2 0}, imperfect on {10 1 1}
Not Available
Mohs Hardness
7.5-8
5-6.5
Chemical Composition
Be 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
SiO 2 · nH 2OGemdat.org , Management Team (2012)