Uneven-Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001)
ConchoidalGemdat.org, Management Team (2012), ConchoidalGemdat.org, Management Team (2012)
The chief constituent Lapis Lazuli is Lazurite, with the following chemical formula: (Na,Ca)8Al6Si6O24(S,SO)4
(Cu) 3(OH) 2(CO 3) 2 + Cu 2(CO 3)(OH) 2Gemdat.org , Management Team (2012)