Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Uneven, Subconchoidal, Splintery
Good on {110}, poor on {100}
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
{010} Perfect, {001} Distinct
Fe3+ PO 4 · 2H 2OAnthony et al , Handbook of Mineralogy (2001)