Uneven, Subconchoidal, Uneven, Subconchoidal, Splintery, UnevenArthur Thomas, Gemstones (2009)
Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Metallic
Good on {110}, poor on {100}
Distinct on [010] and [100] poor on [101]
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
PbCa 3Zn 4(SiO 4) 4Anthony et al , Handbook of mineralogy (2001)