Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
perfect along [010] and [100]
Cu 5(SiO 3) 4(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Good on {110}, (110) ^ (1 1 0) ≈87°; parting on {100}
(Na,Fe,Ca)Si 2O 6Ulrich Henn and Claudio C.