ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Uneven, Brittle, Metallic, Brittle, Metallic, Brittle, Metallic
ZrO 2Arthur Thomas , Gemstones (2009)
(Na,Fe,Ca)Si 2O 6Ulrich Henn and Claudio C.