Kyanite is a gemstone quality aluminum silicate sometimes referred to as disthene, rhaeticite or cyanite. In addition to blue, kyanite can also be colorless, white, gray, green, orange or yellow. With kyanite, color is typically not consistent throughout. In fact, most stones exhibit areas of light to dark color zones, along with white streaks or blotches.Kyanite is a member of the aluminosilicate series and exhibits a distinctive property known as anisotropism. Kyanite can be very easily identified by its dual hardness. Many materials exhibit variable hardness on different crystal faces, but kyanite's variable hardness can be seen in the very same crystal. As a result of its distinct dual hardness and its frequent habit of color streaking and blotching, kyanite can be very easy to identify from other gems.Kyanite can be transparent to translucent. Transparent specimens are most desirable. Almost all kyanite stones will exhibit some visible flaws. Color zoning is often mistaken for internal inclusions.