While comparing Strontium Titanate 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 Strontium Titanate and Sillimanite chemical formula.
Another important criteria for qualitative analysis of gemstones is Strontium Titanate and Sillimanite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Strontium Titanate and Sillimanite Optical Properties during the identification of gemstone. Specific gravity of Strontium Titanate is 3.20-3.26 whereas that of Sillimanite is 3.20-3.26.