Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
None, but may exhibit slight parting
(Mg,Zn)Al 2O 4Gemdat.org , Management Team (2012)
{001} Perfect, {010} Good
KAlSi 3O 8Michael OâDonoghue , Gems, Sixth Edition (2006)