Uneven-Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001)
Conchoidal, ConchoidalAnthony et al, Conchoidal, Brittle, Conchoidal
The chief constituent Lapis Lazuli is Lazurite, with the following chemical formula: (Na,Ca)8Al6Si6O24(S,SO)4
(Zn,Cu)Al 6(PO 4) 4(OH) 8 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)