Blue John and Topaz Physical Properties

Blue John and Topaz Chemical Formula

While comparing Blue John and Topaz 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 Blue John and Topaz chemical formula.

• Chemical formula of Blue John- CaF 2Michael O’Donoghue , Gems, Sixth Edition (2006)
• Chemical formula of Topaz- Al₂SiO₄(F,OH)₂

Blue John and Topaz Specific Gravity

Another important criteria for qualitative analysis of gemstones is Blue John and Topaz Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Blue John and Topaz Optical Properties during the identification of gemstone. Specific gravity of Blue John is 3.49-3.57 whereas that of Topaz is 3.49-3.57.