Conchoidal, ConchoidalArthur Thomas, Gemstones (2009)
ConchoidalArthur Thomas, Gemstones (2009)
K(Ca,Na) 2Si 4O 10(OH,F) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Mg,Zn)Al 2O 4Gemdat.org , Management Team (2012)