Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Uneven-Conchoidal, ConchoidalWalter Schumann
The chief constituent Lapis Lazuli is Lazurite, with the following chemical formula: (Na,Ca)8Al6Si6O24(S,SO)4
None, but may exhibit slight parting
(Mg,Zn)Al 2O 4Gemdat.org , Management Team (2012)