Figure 5. Scanning electron microscope images showing the pyrite framboids (PF2) interpreted as microbial colonies within the dark-grey minor lamellae of Zoophycos spreiten. (a–d) The PF2 consist of sheathed (black arrows in b and d) and hollow (white arrow in b) sub-micron balls with thick wall; (b) is the close-up of (a), and (d) is the close-up of (c). PF2 are hosted in the environment rich in clay minerals and organic material in (a) and (c).