Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
Subconchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
None, may show partings on {0001} and {10 1 1}
{0001} good, {10 1 0} parting