An aluminium cube is being levitated and melted by the magnetic field of a high frequency current through a water-cooled copper coil.

Note the shape of the conical coil, with one turn on the top wound in the opposite direction, causing opposing magnetic fields.
Aluminum sample weitht: 2.6 grams. Power Inverter: 1.6 kW. Frequency: 204 kHz. Peak temperature: 1200° C (2192° F)   Physics details: PDF