Uneven, UnevenAnthony et al, Handbook of mineralogy (2001)
ConchoidalWalter Schumann, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Metallic
[001] perfect; [100] distinct
Perfect on {010}, good on {100}
Pb 5Cu 2(SO 4) 3(CO 3)(OH) 6Anthony et al , Handbook of mineralogy (2001)
Be 2BO 3(OH)Ulrich Henn and Claudio C.