Quartz and Common Opal Physical Properties
Tenacity
Brittle
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.65
  
1.98-2.50
  
Fracture
Conchoidal, Conchoidal, Brittle, Gems
  
Conchoidal, Conchoidal, Gemstones of the world (2001)
  
Cleavage
{0110} Indistinct
  
Not Available
  
Mohs Hardness
7
  
5.5-6.5
  
Chemical Composition
SiO2
  
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
  
Quartz and Common Opal Chemical Formula
While comparing Quartz and Common Opal 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 Quartz and Common Opal chemical formula.
- Chemical formula of Quartz- SiO2
- Chemical formula of Common Opal- SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
Quartz and Common Opal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Quartz and Common Opal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Quartz and Common Opal Optical Properties during the identification of gemstone. Specific gravity of Quartz is 1.98-2.50 whereas that of Common Opal is 1.98-2.50.