Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Subconchoidal, Uneven, Conchoidal
(Mg,Fe2+ ) 9(SiO 4) 4(F,OH)) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
None, but may exhibit slight parting
(Mg,Zn)Al 2O 4Gemdat.org , Management Team (2012)