Brittle, Metallic, Brittle, Metallic
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009)
CaZnSiO 4 · H 2OAnthony et al , Handbook of mineralogy (2001)
K(Ca,Na) 2Si 4O 10(OH,F) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references