Blue John and Ludlamite Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.00-3.25
  
3.1-3.2
  
Fracture
Not Available
  
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
  
Cleavage
Not Available
  
Vitreous, pearly on cleavage
  
Mohs Hardness
Not Available
  
3-4
  
Chemical Composition
CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)
  
(Fe2+ ,Mg,Mn2+ ) 3(PO 4) 2 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
  
Blue John and Ludlamite Chemical Formula
While comparing Blue John and Ludlamite 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 Ludlamite chemical formula.
- Chemical formula of Blue John- CaF 2Michael OâDonoghue , Gems, Sixth Edition (2006)
- Chemical formula of Ludlamite- (Fe2+ ,Mg,Mn2+ ) 3(PO 4) 2 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Blue John and Ludlamite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Blue John and Ludlamite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Blue John and Ludlamite Optical Properties during the identification of gemstone. Specific gravity of Blue John is 3.1-3.2 whereas that of Ludlamite is 3.1-3.2.