Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Uneven, ConchoidalWalter Schumann, Conchoidal
None, may show partings on {0001} and {10 1 1}
Fe 2O 3Arthur Thomas , Gemstones (2009)
Uneven, Irregular, Conchoidal
Ca 3Al 2(SiO 4) 3-x(OH) 4x (x=0.2 to 1.5)Anthony et al , Handbook of mineralogy (2001)