Subconchoidal, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
TiO 2Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
Ca 5(PO 4) 3FAnthony et al , Handbook of mineralogy (2001)