AIUI, things that float in a magnetic field at ~room temperature are moderately common claims, and this is really the only evidence that LK-99 might be a room-temperature superconductor. The published ancillary evidence in the original paper actually raises red flags that isn't a superconductor--the "0 resistivity" domain in their temperature-dependent resistivity plot is (when you realize the units they're using) actually slightly less resistive than regular copper wire, which suggests that the sharp drop in resistivity may be nothing more than a pedestrian phase change in the material.
> things that float in a magnetic field at ~room temperature are moderately common claims
At monopolar magnetic fields weak enough to come from a permanent magnet is a lot rarer.
Almost all superconductor claims come from measuring magnetic resonance or direct resistance measurements. Both are noisy things to measure, and won't get you reliable results.
