Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Uneven
Gems, Sixth Edition (2006), Gems, Sixth Edition (2006)
Mn 3B 7O 13ClMichael OâDonoghue , Gems, Sixth Edition (2006)
SiO 2Michael OâDonoghue , Gems, Sixth Edition (2006)