File:Diamagnetic levitation diagram.gif

The green oval indicates an area where the pull of the upper magnet is stronger than that of gravity, ideally the levitating magnet is right at the border, so it is weightless. The red oval indicates a rough shape to the levitating magnet's field. The blue bumps show a reflected magnetic field from the permanent magnet's own. Magnet poles are attracted to the opposite pole of themself and of other magnets. A diamagnetic material (like bismuth) reflects a small portion of that field back (of the same pole that is nearest to it) repelling the magnet. Thus the magnet is very weakly pushed away from both diamagnetic materials as long as the poles directly face them (which is accomplished by the upper magnet and gravity perfectly aligning it).