It is powerful, healing and calming. It is good to keep by you at night to keep negative spirits and energy and entities away. Kyanite is the only stone that NEVER needs clearing because it never picks up negative energy. It can also be used to clear other rocks.
The first picture is blue kyanite, polished and rough. The second and third pics are black kyanite. Kyanite has many layers so it's texture is different than most rocks.
I LOVE THIS CRYSTAL!