Biotite and Sapphire Physical Properties
Tenacity
Brittle
  
Not Available
  
Solubility
Not Available
  
insoluble
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.7-3.3
  
3.95-4.03
  
Fracture
Uneven, Even, Yellow, White
  
Uneven, Uneven, Gems, Sixth Edition (2006)
  
Cleavage
Perfect on the {001}
  
None, but may exhibit parting
  
Mohs Hardness
2.5-3.0
  
9
  
Chemical Composition
K(Mg,Fe++)3[AlSi3O10(OH,F)2
  
Al 2 O 3
  
Biotite and Sapphire Chemical Formula
While comparing Biotite and Sapphire 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 Biotite and Sapphire chemical formula.
- Chemical formula of Biotite- K(Mg,Fe++)3[AlSi3O10(OH,F)2
- Chemical formula of Sapphire- Al 2 O 3
Biotite and Sapphire Specific Gravity
Another important criteria for qualitative analysis of gemstones is Biotite and Sapphire Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Biotite and Sapphire Optical Properties during the identification of gemstone. Specific gravity of Biotite is 3.95-4.03 whereas that of Sapphire is 3.95-4.03.