Kyanite and Erythrite Physical Properties
Tenacity
Brittle
  
Sectile
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.53-3.65
  
3.06
  
Fracture
Splintery, Brittle, Metallic
  
Sectile Curved shavings or scrapings produced by a knife blade, (e.g. graphite).
  
Cleavage
[100] perfect [010] imperfect with 79° angle between
  
Perfect on {010}; poor on {100} and { 1 02}.
  
Mohs Hardness
4-7
  
Not Available
  
Chemical Composition
Not Available
  
Co3(AsO4)2•8(H2O)
  
Kyanite and Erythrite Chemical Formula
While comparing Kyanite and Erythrite 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 Kyanite and Erythrite chemical formula.
>- Chemical formula of Erythrite- Co3(AsO4)2•8(H2O)
Kyanite and Erythrite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Kyanite and Erythrite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Kyanite and Erythrite Optical Properties during the identification of gemstone. Specific gravity of Kyanite is 3.06 whereas that of Erythrite is 3.06.