Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
{010} Perfect, {001} Distinct
Fe3+ PO 4 · 2H 2OAnthony et al , Handbook of Mineralogy (2001)
{100} perfect; {110} and {1 1 0} good; {010} poor
(Ca,Mn2+ )Si 3O 9Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references