Blue John and Gedrite Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.00-3.25
  
3.15-3.259
  
Fracture
Not Available
  
Not Available
  
Cleavage
Not Available
  
Gedrite Magnesiogedrite , Comments: Dark gray cleavage fragment of magnesiogedrite (gedrite). , Location: Bamble, Telemark, Norway. , Scale: See Image.
  
Mohs Hardness
Not Available
  
5.5-6
  
Chemical Composition
CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)
  
(Mg,Fe2+ ) 2[(Mg,Fe2+ ) 3Al 2](Si 6Al 2)O 22(OH) 2Anthony et al , Handbook of mineralogy (2001)
  
Blue John and Gedrite Chemical Formula
While comparing Blue John and Gedrite 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 Gedrite chemical formula.
- Chemical formula of Blue John- CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)
- Chemical formula of Gedrite- (Mg,Fe2+ ) 2[(Mg,Fe2+ ) 3Al 2](Si 6Al 2)O 22(OH) 2Anthony et al , Handbook of mineralogy (2001)
Blue John and Gedrite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Blue John and Gedrite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Blue John and Gedrite Optical Properties during the identification of gemstone. Specific gravity of Blue John is 3.15-3.259 whereas that of Gedrite is 3.15-3.259.