Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Mg 3(Al,Cr) 2(SiO 4) 3Gemdat.org , Management Team (2012)
perfect along [010] and [100]
Cu 5(SiO 3) 4(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references