When it comes to choosing the best pick among Gems for Aries gemstones, Kyanite is known to be a popular choice!Physical properties of Kyanite include its hardness, gravity, fracture, cleavage, etc. For any gemstone crystal, Kyanite 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. Kyanite cleavage is nothing but the plane across which the crystal splits during cutting. Kyanite cleavage is  perfect  imperfect with 79° angle between,and specific gravity of Kyanite is 3.53-3.65.
The physical properties of Kyanite, 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.