Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Metallic
Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Metallic
PbCa 3Zn 4(SiO 4) 4Anthony et al , Handbook of mineralogy (2001)
Mg 2Si 2O 6Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references