Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
(Fe2+ ,Mg)Al 2(PO 4) 2(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006)
{010} Perfect, {001} Distinct
Fe3+ PO 4 · 2H 2OAnthony et al , Handbook of Mineralogy (2001)