Conchoidal, Gems
Subconchoidal, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
NaAl 3(PO 4) 2(OH) 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
TiO 2Michael OâDonoghue , Gems, Sixth edition (2006) More from other references