Lapis lazuli and Topaz Physical Properties

Lapis lazuli and Topaz Chemical Formula

While comparing Lapis lazuli 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 Lapis lazuli and Topaz chemical formula.

• Chemical formula of Lapis lazuli- The chief constituent Lapis Lazuli is Lazurite, with the following chemical formula: (Na,Ca)₈Al₆Si₆O₂₄(S,SO)₄
• Chemical formula of Topaz- Al₂SiO₄(F,OH)₂

Lapis lazuli and Topaz Specific Gravity

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