Neptunite and Kyanite Physical Properties
Tenacity
Brittle
  
Brittle
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.19-3.23
  
3.53-3.65
  
Fracture
Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
  
Splintery, Brittle, Metallic
  
Cleavage
{110} good
  
[100] perfect [010] imperfect with 79° angle between
  
Mohs Hardness
5-6
  
4-7
  
Chemical Composition
KNa 2Li(Fe2+ ,Mn2+ ) 2Ti 2Si 8O 24Michael OâDonoghue , Gems, Sixth Edition (2006)
  
Not Available
  
Neptunite and Kyanite Chemical Formula
While comparing Neptunite and Kyanite 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 Neptunite and Kyanite chemical formula.
- Chemical formula of Neptunite- KNa 2Li(Fe2+ ,Mn2+ ) 2Ti 2Si 8O 24Michael OâDonoghue , Gems, Sixth Edition (2006)
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Neptunite and Kyanite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Neptunite and Kyanite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Neptunite and Kyanite Optical Properties during the identification of gemstone. Specific gravity of Neptunite is 3.53-3.65 whereas that of Kyanite is 3.53-3.65.