Black Opal and Purpurite Physical Properties

Black Opal and Purpurite Chemical Formula

While comparing Black Opal and Purpurite 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 Black Opal and Purpurite chemical formula.

• Chemical formula of Black Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
• Chemical formula of Purpurite- MnPO 4Walter Schumann , Gemstones of the world (2001) More from other references

Black Opal and Purpurite Specific Gravity

Another important criteria for qualitative analysis of gemstones is Black Opal and Purpurite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Black Opal and Purpurite Optical Properties during the identification of gemstone. Specific gravity of Black Opal is 3.2-3.4 whereas that of Purpurite is 3.2-3.4.