Ettringite and Sillimanite Physical Properties
Tenacity
Not Available
  
Tough
  
Solubility
Partially soluble in water
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
1.77
  
3.20-3.26
  
Fracture
Not Available
  
Splintery
  
Cleavage
Perfect on {10 1 0}
  
{010} perfect
  
Mohs Hardness
2-2.5
  
6-7.5
  
Chemical Composition
Ca 6Al 2(SO 4) 3(OH) 12 26H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
  
Al 2SiO 5Michael OâDonoghue , Gems, Sixth Edition (2006)
  
Ettringite and Sillimanite Chemical Formula
While comparing Ettringite 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 Ettringite and Sillimanite chemical formula.
- Chemical formula of Ettringite- Ca 6Al 2(SO 4) 3(OH) 12 26H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
- Chemical formula of Sillimanite- Al 2SiO 5Michael OâDonoghue , Gems, Sixth Edition (2006)
Ettringite and Sillimanite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Ettringite and Sillimanite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Ettringite and Sillimanite Optical Properties during the identification of gemstone. Specific gravity of Ettringite is 3.20-3.26 whereas that of Sillimanite is 3.20-3.26.