Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Metallic
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
PbCa 3Zn 4(SiO 4) 4Anthony et al , Handbook of mineralogy (2001)
SiO 2Ulrich Henn and Claudio C.