Precious Opal and Corundum Physical Properties
Tenacity
Not Available
  
Brittle
  
Solubility
Not Available
  
insoluble
  
Durability
Not Available
  
Not Available
  
Specific Gravity
1.98-2.25
  
3.90-4.05
  
Fracture
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references
  
Uneven, Uneven, Gems, Difficult, Fibrous
  
Cleavage
Not Available
  
None – parting in 3 directions
  
Mohs Hardness
5-6.5
  
9
  
Chemical Composition
SiO 2 · nH 2OGemdat.org , Management Team (2012)
  
Al 2O 3Arthur Thomas , Gemstones (2009)
  
Precious Opal and Corundum Chemical Formula
While comparing Precious Opal and Corundum 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 Precious Opal and Corundum chemical formula.
- Chemical formula of Precious Opal- SiO 2 · nH 2OGemdat.org , Management Team (2012)
- Chemical formula of Corundum- Al 2O 3Arthur Thomas , Gemstones (2009)
Precious Opal and Corundum Specific Gravity
Another important criteria for qualitative analysis of gemstones is Precious Opal and Corundum Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Precious Opal and Corundum Optical Properties during the identification of gemstone. Specific gravity of Precious Opal is 3.90-4.05 whereas that of Corundum is 3.90-4.05.