|Ferromagnetic||Attracted to a magnet and can be made into a magnet|
|Paramagnetic||Attracted to a magnet, but can not be made into a magnet|
|Diamagnetic||Repulsed by a magnetic field|
Levitating a Sheet of Carbon
He uses both 1/4" N42 cube magnets and 1/8" N50 cube magnets.
He says that rectangular and circular magnets will not work.
This is possible because both water and carbon are diamagnetic - repulsed by a magnet. For more information, see The Frog That Learned to Fly.
I remembered the Cavendish Balance (1783 AD) from physics - this is what was used to measure the gravitational constant. Basically, it is a torsion pendulum which allows the measurement of very weak forces. I figured, what the heck, I would make one and try to see if I could use it to detect diamagnetism .. and it worked.
First I used pencil leads - the kind used to refill mechanical pencils. Then I tried a piece of wood .. a stick from outside, then a match stick. They all worked. Eventually, I tried a piece of chalk and a lego piece - they also worked.
I also had a few notable failures
I tried just putting a loop in the thread to support the lead .. but that was very hard to balance. I now use a spreader and 2 vertical loops .. much easier. Be sure to make the loops large enough so that the magnet affects the object placed in them and not the wooden spreader .. I use about an inch.
They say that bismuth is a better diamagnet than anything else on the planet. Well, that may be true, but my experience is that pencil leads are pretty good. I obtained 2 samples of bismuth hopper crystals at a local rock and mineral show. My original plan was to melt them down and make a bismuth rod. However, being basically lazy, I decided to simply tie them to a long stick and see what happens. As luck would have it, this was the first stick I tried that was not repelled by a magnet. Perhaps this is because it was collected in winter. (It was very light and probably dry.) Because the crystals were different sizes the balance point was closer to the larger crystal.
Well, it worked .. but I was not impressed. The pencil leads were much better.