Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Al 2SiO 5Arthur Thomas , Gemstones (2009)
Uneven, Subconchoidal, Splintery
Good on {110}, poor on {100}
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references