Subconchoidal, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Uneven
TiO 2Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
Mn 3B 7O 13ClMichael OâDonoghue , Gems, Sixth Edition (2006)