Opal and Quartz Physical Properties
Tenacity
BrittleWalter Schumann
  
Brittle
  
Solubility
hot salt water
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
1.98-2.25
  
2.65
  
Fracture
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references, Brittle
  
Conchoidal, Conchoidal, Brittle, Gems
  
Cleavage
None
  
{0110} Indistinct
  
Mohs Hardness
5-6.5
  
7
  
Chemical Composition
SiO2 · nH2O
  
SiO2
  
Opal and Quartz Chemical Formula
While comparing Opal and Quartz 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 Opal and Quartz chemical formula.
- Chemical formula of Opal- SiO2 · nH2O
- Chemical formula of Quartz- SiO2
Opal and Quartz Specific Gravity
Another important criteria for qualitative analysis of gemstones is Opal and Quartz Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Opal and Quartz Optical Properties during the identification of gemstone. Specific gravity of Opal is 2.65 whereas that of Quartz is 2.65.