Biotite and Grossular Physical Properties
Tenacity
Brittle
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.7-3.3
  
3.55-3.73
  
Fracture
Uneven, Even, Yellow, White
  
Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
  
Cleavage
Perfect on the {001}
  
none
  
Mohs Hardness
2.5-3.0
  
7-7.5
  
Chemical Composition
K(Mg,Fe++)3[AlSi3O10(OH,F)2
  
Ca 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)
  
Biotite and Grossular Chemical Formula
While comparing Biotite and Grossular 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 Grossular chemical formula.
- Chemical formula of Biotite- K(Mg,Fe++)3[AlSi3O10(OH,F)2
- Chemical formula of Grossular- Ca 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)
Biotite and Grossular Specific Gravity
Another important criteria for qualitative analysis of gemstones is Biotite and Grossular Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Biotite and Grossular Optical Properties during the identification of gemstone. Specific gravity of Biotite is 3.55-3.73 whereas that of Grossular is 3.55-3.73.