Selenite and Onyx Physical Properties

Selenite and Onyx Chemical Formula

While comparing Selenite and Onyx 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 Selenite and Onyx chemical formula.

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• Chemical formula of Onyx- SiO₂

Selenite and Onyx Specific Gravity

Another important criteria for qualitative analysis of gemstones is Selenite and Onyx Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Selenite and Onyx Optical Properties during the identification of gemstone. Specific gravity of Selenite is 2.55-2.70 whereas that of Onyx is 2.55-2.70.