Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
{0001}, {11 2 0} imperfect
Zn 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Cs,K,Rb)Al 4Be 4(B,Be) 12O 28Anthony et al , Handbook of mineralogy (2001)