Diamagnetic Trap Levitation: tiny neodymium cube magnet trapped between two diamagnetic discs of pyrolytic graphite. Diamagnetic substances only have magnetic fields of their own when placed in an external magnetic field from another source- here the cube shaped magnet supplies the field. Diamagnetic fields are pretty weak, so the top magnet is adjusted to help lift the tiny magnet against gravity where the slightest air currents can send it dancing. A creation of Martin Simon in my collection s