ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Uneven
Mg 3(Al,Cr) 2(SiO 4) 3Gemdat.org , Management Team (2012)
Mn 3B 7O 13ClMichael OâDonoghue , Gems, Sixth Edition (2006)