Brittle, Metallic, Brittle, Metallic
Conchoidal, Uneven, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal to uneven
CaZnSiO 4 · H 2OAnthony et al , Handbook of mineralogy (2001)
Ca 5(PO 4) 3(F,OH,Cl)Walter Schumann , Gemstones of the world (2001) More from other references