Fig. 14From: Rock varnish on architectural stone: microscopy and analysis of nanoscale manganese oxide deposits on the Smithsonian Castle, Washington, DCMicrobiological activity on rock varnish. a SE image depicting a long (many 10 s of microns) filament attached to the sandstone surface. b X-ray image overlay of highlighted region in a. c Higher resolution SEM-based compositional image showing microbial microstructure over Mn-rich rock varnish on a gatepost sampleBack to article page