1 Physical Properties
1.1 Tenacity
1.2 Solubility
Not Available
Not Available
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
2.90-2.982.50-3.00
1
7.18
1.5 Fracture
Conchoidal, Brittle, Conchoidal, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Uneven-Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001)
1.6 Cleavage
Rare tabular and prismatic crystals. Usually occurs as fibrous, parallel veins that break off into cleavage fragments.
3,6
1.7 Mohs Hardness
1.8 Chemical Composition
CaSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
The chief constituent Lapis Lazuli is Lazurite, with the following chemical formula: (Na,Ca)8Al6Si6O24(S,SO)4