Fig. 4: SEM images of bio-geochemical degradation areas on the glaze surface caused by red coral residues.

a Red coral-induced bio-geochemical degradation pits. b Magnified image of box b in (a). c Rod crystals in pits.

a Red coral-induced bio-geochemical degradation pits. b Magnified image of box b in (a). c Rod crystals in pits.