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