Neptunite and Blue John Physical Properties
Tenacity
Brittle
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.19-3.23
  
3.00-3.25
  
Fracture
Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
  
Not Available
  
Cleavage
{110} good
  
Not Available
  
Mohs Hardness
5-6
  
Not Available
  
Chemical Composition
KNa 2Li(Fe2+ ,Mn2+ ) 2Ti 2Si 8O 24Michael OâDonoghue , Gems, Sixth Edition (2006)
  
CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)
  
Neptunite and Blue John Chemical Formula
While comparing Neptunite and Blue John 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 Neptunite and Blue John chemical formula.
- Chemical formula of Neptunite- KNa 2Li(Fe2+ ,Mn2+ ) 2Ti 2Si 8O 24Michael OâDonoghue , Gems, Sixth Edition (2006)
- Chemical formula of Blue John- CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)
Neptunite and Blue John Specific Gravity
Another important criteria for qualitative analysis of gemstones is Neptunite and Blue John Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Neptunite and Blue John Optical Properties during the identification of gemstone. Specific gravity of Neptunite is 3.00-3.25 whereas that of Blue John is 3.00-3.25.