Sillimanite and Rubellite Physical Properties
Tenacity
Tough
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.20-3.26
  
3.01-3.06
  
Fracture
Splintery
  
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
  
Cleavage
{010} perfect
  
Not Available
  
Mohs Hardness
6-7.5
  
7-7.5
  
Chemical Composition
Al 2SiO 5Michael OâDonoghue , Gems, Sixth Edition (2006)
  
Na(Li 1.5Al 1.5)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012) Formula given for elbaite.
  
Sillimanite and Rubellite Chemical Formula
While comparing Sillimanite and Rubellite 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 Sillimanite and Rubellite chemical formula.
- Chemical formula of Sillimanite- Al 2SiO 5Michael OâDonoghue , Gems, Sixth Edition (2006)
- Chemical formula of Rubellite- Na(Li 1.5Al 1.5)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012) Formula given for elbaite.
Sillimanite and Rubellite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Sillimanite and Rubellite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Sillimanite and Rubellite Optical Properties during the identification of gemstone. Specific gravity of Sillimanite is 3.01-3.06 whereas that of Rubellite is 3.01-3.06.