Abstract
Depth profiling analysis of native gold samples using X-ray photoelectron spectroscopy (XPS) shows the surface layers of lode gold to be significantly enriched with silver to a depth of 0.02–0.04 microns and the surface layers of placer gold to be depleted of silver up to a depth of several microns. The change in the surface composition of gold samples taken from oxidation zones is of more complicated character. Model experiments suggest the surface segregation of silver in lode gold samples to be due to outward diffusion and oxidation of silver at the surface. In placer gold the depletion of silver is caused by leaching of the latter from the surface layers.
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Nefedov, V.I., Zhavoronkov, N.M., Machavariani, G.V. et al. The variation of silver content in native gold particles as revealed by ESCA. Phys Chem Minerals 8, 193–196 (1982). https://doi.org/10.1007/BF00309476
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DOI: https://doi.org/10.1007/BF00309476