Fine quality Kyanite may be confused in appearance with spinel or blue sapphires from Burma. Kyanite name derives from the Greek word "kyanos", meaning deep blue. Kyanite is also of interest because of the extreme variablity in hardness with direction. In one direction, the hardness is 4.5 and in the other it is 7. Very easy cleavage is encountered in one direction with a less perfect cleavage occurring at 74 degrees to the first.