Jet and Sillimanite Physical Properties
Tenacity
Not Available
  
Tough
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
1.19-1.35
  
3.20-3.26
  
Fracture
ConchoidalWalter Schumann, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references
  
Splintery
  
Cleavage
Not Available
  
{010} perfect
  
Mohs Hardness
2.5-4
  
6-7.5
  
Chemical Composition
Not Available
  
Al 2SiO 5Michael OâDonoghue , Gems, Sixth Edition (2006)
  
Jet and Sillimanite Chemical Formula
While comparing Jet and Sillimanite 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 Jet and Sillimanite chemical formula.
>- Chemical formula of Sillimanite- Al 2SiO 5Michael OâDonoghue , Gems, Sixth Edition (2006)
Jet and Sillimanite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Jet and Sillimanite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Jet and Sillimanite Optical Properties during the identification of gemstone. Specific gravity of Jet is 3.20-3.26 whereas that of Sillimanite is 3.20-3.26.