Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
Conchoidal, Uneven, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal to uneven
Ca 2 MgAl 2 BSi 4 O 15 OH Gemdat.org, Management Team (2012)
Ca 5(PO 4) 3(F,OH,Cl)Walter Schumann , Gemstones of the world (2001) More from other references