Fig 7.

SEM images of treated carbonate and silicate stones. (a) Newly formed bacterial calcite along with calcified bacterial cells (bc) embedded in EPS on the calcarenite stone. (b) Detail of calcified bacterial cells attached to the calcite grains in the calcarenite stone. (c) Vaterite spheroidal precipitates (vat) on the quartz grains of the sandstone, along with a few bacterial cells embedded in EPS. (d) Bacterial cells partially entombed in vaterite spherulitic precipitates attached to quartz crystals.