Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
MgF 2Ulrich Henn and Claudio C.
Fe 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)