Fig. 5From: Copper precipitation as consequence of steel corrosion in a flow-through experiment mimicking a geothermal production wellElectron microprobe pictures of rock thin sections after the experiments: Roundish grey areas represent quartz particles of the sandstone; black areas indicate pore space; white areas indicate high-density. Top left oxic-treated sandstone sample (O). Top right enlargement of one pore of the top–left picture filled with Fe-hydroxides (grey areas) and pure Cu (white needle-shaped areas). Bottom left sample from experiment C; Bottom right sample from experiment E (use of stainless steel) with intact pore space. The corresponding table shows semi-quantitative EDX results of elemental composition of four different locations as indicated by numbers Back to article page