Fig. 13From: Rock varnish on architectural stone: microscopy and analysis of nanoscale manganese oxide deposits on the Smithsonian Castle, Washington, DCDistribution of Mn in rock varnish. The composite x-ray image shows that Mn enrichment occurs in discrete discontinuous zones at the rock-atmosphere interface. Deconvolved low energy x-ray peaks show the relative contributions of Mn and Fe in the highlighted regionBack to article page