Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Metallic
ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)
PbCa 3Zn 4(SiO 4) 4Anthony et al , Handbook of mineralogy (2001)
SiO 2(+Al 2O 3)Walter Schumann , Gemstones of the world (2001)