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