Sillimanite and Apatite Physical Properties

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 O’Donoghue , 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.