Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Brittle, Metallic, Brittle, Metallic
CaCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
CaZnSiO 4 · H 2OAnthony et al , Handbook of mineralogy (2001)