Series of images presenting material with different levels of proton-induced processing. The three types of carbon structures were observed underneath the graphitic layer after complete bombardment of sample 3 with the total fluence of 6.76 × 10¹⁶ ions/cm². The particles are still visible, but they contain longer graphene layers compared to those observed in the original grains. In addition, one can see the formation of more closed buckyonions and fullerenes. The right micrograph finally shows grains, which are still similar to the unprocessed fullerene-like grains.