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