Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Ca 5(PO 4) 3FAnthony et al , Handbook of mineralogy (2001)
Ca 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)