GOLD AND SILVER ALLOY COATINGS OVER COPPER: AN EXAMINATION OF SOME ARTEFACTS FROM ECUADOR AND COLOMBIA

Resumen

An examination, by metallography, atomic absorption spectrophotometry, and electron probe microanalysis of some decorative metalwork and small items such as needles and fish‐hooks from Ecuador and Colombia revealed that ‘fusion‐gilding’ or ‘wash‐gilding’ was employed in the manufacture of many artefacts. The coatings found included silver alloy coatings over copper and gold alloys over copper. The coatings are often themselves superficially enriched at the surface; they are thick, and completely different from the surfaces found on depletion gilded objects which are far more common in ancient Colombia. The evidence from Ecuador is piecemeal and a considerable number of additional analyses must be carried out to clarify the extent of use of this surface treatment technology.