Black Opal and Anorthite Physical Properties
Tenacity
Not Available
  
Brittle
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
1.97-2.22
  
2.77
  
Fracture
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
  
Uneven, Uneven, Gems, Sixth Edition (2006)
  
Cleavage
Not Available
  
Perfect [001] good [010] poor [110]
  
Mohs Hardness
6-6.5
  
6-6.5
  
Chemical Composition
SiO 2 + H 2OUlrich Henn and Claudio C.
  
CaAl 2Si 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)
  
Black Opal and Anorthite Chemical Formula
While comparing Black Opal and Anorthite 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 Anorthite chemical formula.
- Chemical formula of Black Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
- Chemical formula of Anorthite- CaAl 2Si 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)
Black Opal and Anorthite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Black Opal and Anorthite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Black Opal and Anorthite Optical Properties during the identification of gemstone. Specific gravity of Black Opal is 2.77 whereas that of Anorthite is 2.77.