Kyanite and Brucite Physical Properties
Tenacity
Brittle
  
Sectile
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.53-3.65
  
2.39
  
Fracture
Splintery, Brittle, Metallic
  
Irregular
  
Cleavage
[100] perfect [010] imperfect with 79° angle between
  
Perfect on {0001}
  
Mohs Hardness
4-7
  
2.5
  
Chemical Composition
Not Available
  
Mg(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006)
  
Kyanite and Brucite Chemical Formula
While comparing Kyanite and Brucite 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 Brucite chemical formula.
>- Chemical formula of Brucite- Mg(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006)
Kyanite and Brucite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Kyanite and Brucite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Kyanite and Brucite Optical Properties during the identification of gemstone. Specific gravity of Kyanite is 2.39 whereas that of Brucite is 2.39.