Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Conchoidal, ConchoidalWalter Schumann
Distinct on {11 2 0}, imperfect on {10 1 1}
Be 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Quartz: SiO2 Rutile: TiO2