The six magnets from Forcefield (#27 dimensions: 1.25" x 0.56", 0.125" thick), which cost $2.01 each, have their poles on the 1.25" x 0.56" faces. They are placed on a 2" wide by 0.125" thick steel bar from Home Depot which cost $9.41. The pole arrangement is:
N S N
N S N
so that with respect to the photograph above, the magnets are attracting from left to right but repelling from upper to lower.
A piece of Science Toy pyrolytic graphite is floating above the magnets. This material was purchased from Simon Quellen's catalog, three pieces for $6.00 plus $5.00 for shipping. This piece has been split from the original and is about 0.5 mm thick.
In order to get the graphite to remain centered, I've added a thin sliver of pyrolytic graphite cut into a lens shape. This shape not only centers the large piece, but also increases the period of oscillations from about 2 to about 5 second.
I've also tried this pattern of poles:
N S N
S N S
The large graphite will stabilize in the center, but seems damped in it's motion and will stabilize in more than one location.