1 Physical Properties
1.1 Tenacity
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
2.50-3.006.86-7.03
1
7.18
1.5 Fracture
Uneven-Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001)
Subconchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Irregular
1.6 Cleavage
3,6
{100} imperfect, {110} indistinct; partings on {111} or {011}
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
SnO 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references