ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Brittle, Metallic, Brittle, Metallic
NaAl 3(PO 4) 2(OH) 4 · 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
CaZnSiO 4 · H 2OAnthony et al , Handbook of mineralogy (2001)