Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references
Ag 3AsS 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
SiO 2 · nH 2OGemdat.org , Management Team (2012)