Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Uneven
Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
Mn 3B 7O 13ClMichael OâDonoghue , Gems, Sixth Edition (2006)
SiCArthur Thomas , Gemstones (2009)