When it comes to choosing the best pick among Blue Gemstones gemstones, Black Opal is known to be a popular choice!Physical properties of Black Opal include its hardness, gravity, fracture, cleavage, etc. For any gemstone crystal, Black Opal Optical Properties are responsible for imparting various physical properties to its structure. Knowledge of these properties is equally important to gem-cutters as well as to consumers. Black Opal cleavage is nothing but the plane across which the crystal splits during cutting. and specific gravity of Black Opal is 1.97-2.22.
The physical properties of Black Opal, in fact, are imparted by the chemical composition of its individual molecule. The reactivity or inertness of the crystal is solely governed by its chemical structure. Chemical composition of Black Opal is represented by SiO 2 + H 2OUlrich Henn and Claudio C..