Black Opal and Boulder Opal Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
1.97-2.22
  
1.98-2.25
  
Fracture
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
  
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
  
Cleavage
Not Available
  
Not Available
  
Mohs Hardness
6-6.5
  
5-6.5
  
Chemical Composition
SiO 2 + H 2OUlrich Henn and Claudio C.
  
SiO 2 + H 2OUlrich Henn and Claudio C.
  
Black Opal and Boulder Opal Chemical Formula
While comparing Black Opal and Boulder 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 Black Opal and Boulder Opal chemical formula.
- Chemical formula of Black Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
- Chemical formula of Boulder Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
Black Opal and Boulder Opal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Black Opal and Boulder Opal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Black Opal and Boulder Opal Optical Properties during the identification of gemstone. Specific gravity of Black Opal is 1.98-2.25 whereas that of Boulder Opal is 1.98-2.25.