Extended Data Fig. 5: Iron valence distribution of the analyzed zone No. 3 from the CE5 agglutinate glass.

HAADF-STEM image (a), EELS Fe valent map (b), Fe3+/∑Fe ratios map (c), and the frequency and cumulative distributions (d) of the Fe3+/∑Fe ratios of another randomly chosen zone in the CE5 agglutinate.