Sillimanite and Apatite Physical Properties
Tenacity
Tough
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.20-3.26
  
3.16-3.23
  
Fracture
Splintery
  
Conchoidal, Uneven, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal to uneven
  
Cleavage
{010} perfect
  
[0001] indistinct, [1010] indistinct
  
Mohs Hardness
6-7.5
  
5
  
Chemical Composition
Al 2SiO 5Michael OâDonoghue , Gems, Sixth Edition (2006)
  
Ca 5(PO 4) 3(F,OH,Cl)Walter Schumann , Gemstones of the world (2001) More from other references
  
Sillimanite and Apatite Chemical Formula
While comparing Sillimanite and Apatite 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 Apatite chemical formula.
- Chemical formula of Sillimanite- Al 2SiO 5Michael OâDonoghue , Gems, Sixth Edition (2006)
- Chemical formula of Apatite- Ca 5(PO 4) 3(F,OH,Cl)Walter Schumann , Gemstones of the world (2001) More from other references
Sillimanite and Apatite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Sillimanite and Apatite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Sillimanite and Apatite Optical Properties during the identification of gemstone. Specific gravity of Sillimanite is 3.16-3.23 whereas that of Apatite is 3.16-3.23.