Subconchoidal, Uneven, Conchoidal, Uneven
Subconchoidal, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
Mn2+ Al(PO 4)(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
TiO 2Michael OâDonoghue , Gems, Sixth edition (2006) More from other references