Uneven, Conchoidal, Brittle, Metallic, ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Ca 3Cr 2(SiO 4) 3Ulrich Henn and Claudio C.
SrCO 3Walter Schumann , Gemstones of the world (2001) More from other references