Gypsum and Blue John Physical Properties
Tenacity
Flexible
  
Not Available
  
Solubility
Soluble
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.20-2.40
  
3.00-3.25
  
Fracture
Conchoidal, Splintery, Fibrous, UnevenArthur Thomas, Gemstones (2009)
  
Not Available
  
Cleavage
Perfect on {010}, distinct on {100}
  
Not Available
  
Mohs Hardness
2
  
Not Available
  
Chemical Composition
CaSO 4 -2(H 2O)Arthur Thomas , Gemstones (2009)
  
CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)
  
Gypsum and Blue John Chemical Formula
While comparing Gypsum 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 Gypsum and Blue John chemical formula.
- Chemical formula of Gypsum- CaSO 4 -2(H 2O)Arthur Thomas , Gemstones (2009)
- Chemical formula of Blue John- CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)
Gypsum and Blue John Specific Gravity
Another important criteria for qualitative analysis of gemstones is Gypsum and Blue John Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Gypsum and Blue John Optical Properties during the identification of gemstone. Specific gravity of Gypsum is 3.00-3.25 whereas that of Blue John is 3.00-3.25.