Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
Conchoidal, Brittle, Conchoidal
None, may show partings on {0001} and {10 1 1}
Good on [110] and on [001]
Fe 2O 3Arthur Thomas , Gemstones (2009)
[ ]Na2(Mg3Al2)Si8O22(OH)2