Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle
CuAl6(PO4)4(OH)8 • 4H2O
(Cs,Na)(AlSi 2O 6) · 0.5H 2OWalter Schumann , Gemstones of the world (2001) More from other references