Onyx and Rock Crystal Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.55-2.70
  
2.65
  
Fracture
Not Available
  
ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)
  
Cleavage
Indiscernible
  
Not Available
  
Mohs Hardness
6.5-7
  
7
  
Chemical Composition
SiO2
  
SiO 2Walter Schumann , Gemstones of the world (2001)
  
Onyx and Rock Crystal Chemical Formula
While comparing Onyx and Rock Crystal 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 Onyx and Rock Crystal chemical formula.
- Chemical formula of Onyx- SiO2
- Chemical formula of Rock Crystal- SiO 2Walter Schumann , Gemstones of the world (2001)
Onyx and Rock Crystal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Onyx and Rock Crystal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Onyx and Rock Crystal Optical Properties during the identification of gemstone. Specific gravity of Onyx is 2.65 whereas that of Rock Crystal is 2.65.