Common Opal and Gahnite Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
1.98-2.50
  
4.00-4.62
  
Fracture
Conchoidal, Conchoidal, Gemstones of the world (2001)
  
Conchoidal, Uneven
  
Cleavage
Not Available
  
Indistinct parting on [111]
  
Mohs Hardness
5.5-6.5
  
7.5-8
  
Chemical Composition
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
  
ZnAl 2O 4Michael OâDonoghue , Gems, Sixth Edition (2006)
  
Common Opal and Gahnite Chemical Formula
While comparing Common Opal and Gahnite 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 Common Opal and Gahnite chemical formula.
- Chemical formula of Common Opal- SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
- Chemical formula of Gahnite- ZnAl 2O 4Michael OâDonoghue , Gems, Sixth Edition (2006)
Common Opal and Gahnite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Common Opal and Gahnite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Common Opal and Gahnite Optical Properties during the identification of gemstone. Specific gravity of Common Opal is 4.00-4.62 whereas that of Gahnite is 4.00-4.62.