ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Sub-Conchoidal, ConchoidalArthur Thomas, Conchoidal, Uneven
Ca 5(F,Cl)(PO 4) 3Arthur Thomas , Gemstones (2009)
(Fe,Mn)AlPO 4(OH) 2 -H 2OArthur Thomas , Gemstones (2009)