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This work relates a study on a medieval coin found during archaeological works carried out at the site of Senhora do Castelo in Urros (Torre de Moncorvo, Portugal). The artefact has been identified as a coin of D. Afonso IX of Leon (1155-1188). The substratum showed composition typical of bullion, Cu-Ag (30-33%) with minor elements (1% Pb + 0.2% Sn + 0.4% Zn). The corrosion products developed on the coin during the archaeological burial was studied by means of optical microscopy (OM), scanning electron microscopy combined with energy dispersive spectrometry (SEM-EDS), energy dispersive X-ray fluorescence (EDXRF), and X-ray diffraction (XRD). The results show the presence of cuprite, atacamite, chalcocite, native silver, silver oxide and silver sulphide on the outer layers of the coin, which allows deducing the importance of the environment in the corrosion phenomena. [ABSTRACT FROM AUTHOR]

A quantitative evaluation method was elaborated to determine the gold, silver and copper concentration of high gold content objects in a non-destructive way. The spectrum evaluation method rules out the effect of the differences in size, shape and surface. A long measuring time allows qualitative analysis of the trace elements: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In and Zn. Using this method, about 200 golden coins and jewelry from the 10th-15th century Hungary and Byzantium were analyzed. Some of the results are presented here. [ABSTRACT FROM AUTHOR]