Um, yes. And if you have a chunk that big, goodness knows how big a magnet you'd need to levitate it. I can imagine a massive 1 foot cube NiB super magnet that crashes computers in the entire block if you move it a centimetre or two... And probably can't be transported since it sticks to EVERYTHING that's iron or steel.
Have a look around scitoys.com. They have some excellent diamagnetic kits.
And yes, the device IS real, I made it once, it's called Kelvin's thunderstorm.
Ps. Anode? As in electrolysis of molten metal? Cool.