> However, neither diamagnetic levitation nor zero resistance was observed in any of our LK-99 samples. In the synthesized samples, we found few very small piec

> However, neither diamagnetic levitation nor zero resistance was observed in any of our LK-99 samples. In the synthesized samples, we found few very small pieces of materials, either black or pink appearance under optical microscope, with strong para- or ferromagnetic response. That is, these samples move, flip, or stand as the magnet moves underneath, similar to those reported in some videos (e.g., as in Ref. 7) in an attempt to replicate LK-99 diamagnetic levitation. We carefully separated these particles and performed EDX analysis on them. As confirmed by EDX, these magnet-responsive particles have iron inclusions (Fig. 5). This helps to explain our results with magnetic response. Unfortunately, despite all the care has been taken to avoid iron contamination during the process, some remains.