ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Uneven
Conchoidal, Gems
(Mn2+ ,Fe2+ ,Mg,Ca) 2(PO 4)(F,OH)Michael OâDonoghue , Gems, Sixth Edition (2006)
NaAl 3(PO 4) 2(OH) 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references