Fig. 3

SEM images and pyrite energy spectra. (A) Type I pyrite is distributed in clusters; (B) A framboidal pyrite; (C) Type II pyrite ‘floats’ in the shale matrix and has a large diameter; (D) Energy spectrum of type II pyrite.
SEM images and pyrite energy spectra. (A) Type I pyrite is distributed in clusters; (B) A framboidal pyrite; (C) Type II pyrite ‘floats’ in the shale matrix and has a large diameter; (D) Energy spectrum of type II pyrite.