Blue John and Bertrandite Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.00-3.25
  
2.59-2.60
  
Fracture
Not Available
  
Brittle, Metallic, Brittle, Metallic
  
Cleavage
Not Available
  
{001} Perfect, {110} Distinct, {101} Distinct
  
Mohs Hardness
Not Available
  
6-7
  
Chemical Composition
CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)
  
Be 4Si 2O 7(OH) 2Anthony et al , Handbook of mineralogy (2001)
  
Blue John and Bertrandite Chemical Formula
While comparing Blue John and Bertrandite 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 Blue John and Bertrandite chemical formula.
- Chemical formula of Blue John- CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)
- Chemical formula of Bertrandite- Be 4Si 2O 7(OH) 2Anthony et al , Handbook of mineralogy (2001)
Blue John and Bertrandite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Blue John and Bertrandite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Blue John and Bertrandite Optical Properties during the identification of gemstone. Specific gravity of Blue John is 2.59-2.60 whereas that of Bertrandite is 2.59-2.60.