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