UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
Uneven-Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001)
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.
The chief constituent Lapis Lazuli is Lazurite, with the following chemical formula: (Na,Ca)8Al6Si6O24(S,SO)4