When it comes to choosing the best pick among Gems for Sagittarius gemstones, Obsidian is known to be a popular choice!Physical properties of Obsidian include its hardness, gravity, fracture, cleavage, etc. For any gemstone crystal, Obsidian 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. Obsidian cleavage is nothing but the plane across which the crystal splits during cutting. and specific gravity of Obsidian is 2.35-2.60.
The physical properties of Obsidian, 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.