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