Black Opal and Neptunite Physical Properties
Tenacity
Not Available
  
Brittle
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
1.97-2.22
  
3.19-3.23
  
Fracture
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
  
Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
  
Cleavage
Not Available
  
{110} good
  
Mohs Hardness
6-6.5
  
5-6
  
Chemical Composition
SiO 2 + H 2OUlrich Henn and Claudio C.
  
KNa 2Li(Fe2+ ,Mn2+ ) 2Ti 2Si 8O 24Michael OâDonoghue , Gems, Sixth Edition (2006)
  
Black Opal and Neptunite Chemical Formula
While comparing Black Opal and Neptunite 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 Neptunite chemical formula.
- Chemical formula of Black Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
- Chemical formula of Neptunite- KNa 2Li(Fe2+ ,Mn2+ ) 2Ti 2Si 8O 24Michael OâDonoghue , Gems, Sixth Edition (2006)
Black Opal and Neptunite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Black Opal and Neptunite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Black Opal and Neptunite Optical Properties during the identification of gemstone. Specific gravity of Black Opal is 3.19-3.23 whereas that of Neptunite is 3.19-3.23.