Conchoidal, Uneven, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Conchoidal, Brittle, Metallic, ConchoidalArthur Thomas, Gemstones (2009)
Ca 3Fe 2(SiO 4) 3Arthur Thomas , Gemstones (2009)
Ca 3Cr 2(SiO 4) 3Ulrich Henn and Claudio C.