Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Perfect on {001}, good on {210}, poor on {010}
SrSO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Perfect on [001], good on [010], imperfect on [110]
Ca(70-90%)Na(30-10%)(Al,Si)AlSi 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)