Appl Phys A (2013) 113:945–957 DOI 10.1007/s00339-013-7722-3 Ancient silver extraction in the Montevecchio mine basin (Sardinia, Italy): micro-chemical study of pyrometallurgical materials Tilde De Caro · Cristina Riccucci · Erica I. Parisi · Federica Faraldi · D. Caschera Received: 15 April 2013 / Accepted: 19 April 2013 / Published online: 7 May 2013 © Springer-Verlag Berlin Heidelberg 2013 Abstract Different pyrometallurgical materials such as slags, refractory materials and thermally treated lead ores likely related to smelting and extractive processes and chronologically related to Punic and Roman periods (IV– III BC) have been found at Bocche di Sciria and Conca e Mosu in the Montevecchio mine basin (south western Sar- dinia, Italy), where archaeological findings and classical au- thors locate extractive metallurgy activities since pre-Roman times. By means of the combined use of X-ray diffrac- tion (XRD), scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectrometry (EDS), selected- area X-ray photoelectron spectroscopy (XPS) and optical microscopy (OM), micro-chemical and micro-structural in- vestigations have been carried out in order to identify the nature of the pyrometallurgical materials, to decipher the processes carried out there and their technological steps and to determine the technological level of competence reached by the ancient metallurgists. The results confirm that the findings can be associated with smelting and extractive pro- cesses carried out close to the metal ore deposits first for the argentiferous lead production and, then, for the silver re- covery via a cupellation process. Finally, the results disclose the high level of technological competence of the ancient metallurgists able to carry out complex high-temperature processes to treat the argentiferous lead ores and to recover T. De Caro ( ) · C. Riccucci · E.I. Parisi · D. Caschera Istituto per lo Studio dei Materiali Nanostrutturati, Area della Ricerca del CNR RM1—Montelibretti, via Salaria km 29.5, Monterotondo Stazione, Rome, Italy e-mail: tilde.decaro@ismn.cnr.it Fax: +39-06-90672714 F. Faraldi Dipartimento Scienza dei Materiali e Ingegneria Chimica, Politecnico di Torino, Corso Duca degli Abruzzi 24, Torino, Italy low amounts of silver via high-temperature lead-selective oxidation. 1 Introduction The Montevecchio mine basin is located in south western Sardinia (Italy) and is characterised by the presence of large deposits of metal-bearing rocks with lead, tin, copper, silver, zinc, cadmium, nickel and iron ores [1, 2]. Classical authors [1, 3–8] indicated that the metal lode outcrops had been exploited since the Phoenician–Punic times and, then, in Roman times for the silver extraction from argentiferous galena (PbS). Curiously, till now, there are few available scientific data concerning the pyrometal- lurgical activities carried out in the Montevecchio basin dur- ing that period, even though many metal artefacts, ingots and slags as well as mining tools have been found there and remains of Roman galleries and pits following the ore veins are still present [5, 8–10]. The dating of these mining works has been attributed to the Roman period on the basis of some working tools and coins found there while the only Punic artefact found in a gallery seems to be a fragment of a terra cotta lamp. Unfortunately, we have scarce information con- cerning the technology of early mining and smelting in this area of Sardinia and, further, we have neither remains of fur- naces nor results of scientific investigations to determine in detail the nature of the pyrometallurgical processes and the level of technological competence reached by the ancient metallurgists. The accidental discoveries of pyrometallurgical materials such as slags and refractory fragments at Bocche di Sciria and Conca e Mosu associated with pottery, chronologically related to the Punic and Roman periods [8], has allowed us to gain further insight into the ancient extractive activities