1 Physical Properties
1.1 Tenacity
1.2 Solubility
Not Available
Not Available
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
2.50-3.005.85-6.15
1
7.18
1.5 Fracture
Uneven-Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001)
Conchoidal, Metallic, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
1.6 Cleavage
3,6
Fair in four directions forming octahedrons
1.7 Mohs Hardness
1.8 Chemical Composition
The chief constituent Lapis Lazuli is Lazurite, with the following chemical formula: (Na,Ca)8Al6Si6O24(S,SO)4
Cu 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references