Lapis lazuli and Onyx Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.50-3.00
  
2.55-2.70
  
Fracture
Uneven-Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001)
  
Not Available
  
Cleavage
3,6
  
Indiscernible
  
Mohs Hardness
5.5
  
6.5-7
  
Chemical Composition
The chief constituent Lapis Lazuli is Lazurite, with the following chemical formula: (Na,Ca)8Al6Si6O24(S,SO)4
  
SiO2
  
Lapis lazuli and Onyx Chemical Formula
While comparing Lapis lazuli and Onyx physical properties, the important data you should know is its chemical composition. Since chemical formula defines the molecular structure of the crystal, most of the physical properties like color, tenacity, solubility are governed by Lapis lazuli and Onyx chemical formula.
- Chemical formula of Lapis lazuli- The chief constituent Lapis Lazuli is Lazurite, with the following chemical formula: (Na,Ca)8Al6Si6O24(S,SO)4
- Chemical formula of Onyx- SiO2
Lapis lazuli and Onyx Specific Gravity
Another important criteria for qualitative analysis of gemstones is Lapis lazuli and Onyx Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Lapis lazuli and Onyx Optical Properties during the identification of gemstone. Specific gravity of Lapis lazuli is 2.55-2.70 whereas that of Onyx is 2.55-2.70.