Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Uneven
Handbook of mineralogy (2001), Difficult, Fibrous
Mn 3B 7O 13ClMichael OâDonoghue , Gems, Sixth Edition (2006)
Ca 6Si 6O 17(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006)