Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
On {10 1 0}, perfect; parting on {000 1 }
(Zn,Mn2+ )OMichael OâDonoghue , Gems, Sixth Edition (2006)
Good on {110}, (110) ^ (1 1 0) ≈87°; parting on {100}
(Na,Fe,Ca)Si 2O 6Ulrich Henn and Claudio C.