Contents lists available at ScienceDirect Microchemical Journal journal homepage: www.elsevier.com/locate/microc A provenance study of Roman lead-glazed ceramics using lead isotopes and secondary ion mass spectrometry (SIMS) Laura Medeghini a, ⁎ , Mostafa Fayek b , Silvano Mignardi a , Fulvio Coletti c , Alessia Contino d , Caterina De Vito a a Department of Earth Sciences, Sapienza University of Rome, Piazzale A. Moro, 5, 00185 Rome, Italy b Department of Geological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada c Parco Archeologico del Colosseo, Piazza di S. Maria Nova, 53, 00185 Rome, Italy d Segretariato Regionale MIBAC per il Lazio, via di San Michele, 22, 00153 Rome, Italy ARTICLE INFO Keywords: Galena Litharge Ores PCA Pottery Trades ABSTRACT Lead isotope analyses, using secondary ion mass spectrometry (SIMS), are used to trace the provenance of lead minerals involved in the production of Roman lead-glazed ceramics. The Roman archeological ceramic artifacts analyzed in this study were recovered from fve archeological sites in Rome: the Testaccio Market (mid-2nd century AD), the Magna Mater sanctuary and the Domus Tiberiana on the Palatine Hill (late 4th – 5th century AD), the Forum of Caesar (10th - the early 11th century AD) and from the Forum of Nerva (9th – 10th century AD). A comparison of lead isotope ratios from the ceramic artifacts examined with databases of lead isotopes from lead deposits exploited in ancient times suggests that since the 2nd century AD the deposits of the British Isles were the most probable sources of metal involved in the production of Roman lead-glazed ceramics. Furthermore, the results indicate that the lead isotope ratios obtained by SIMS are consistent with values reported in the literature that were obtained by ICP-MS and TIMS. Thus, the efectiveness of in-situ micro-analysis by SIMS is highlighted, considering that it is a less destructive method for the analysis of valuable archeological recovered artifacts. 1. Introduction Numerous studies of glazed coatings on ancient ceramics have aimed to understand the ancient production process, and how it changed and developed through the centuries (see for example [1,2]). During the Hellenistic and Roman Periods, the use of lead com- pounds for glazed coating production was very common [3]. Com- paring to other coatings, the reasons of this wide difusion are several: frst of all the easier preparation, directly from a mixture of lead compound and silica, with reduction in costs; an easier application of the glaze suspension due to the insolubility of lead oxides; the reduction of crack formation in ceramic objects connected to the lower thermal expansion coefcient; and fnally the greater optical brilliance due to the higher specular refectance from the glaze surface [4,5]. The introduction of high-lead coatings, i.e. glazed applied on the surface of ceramics with high amount of lead, appeared in Anatolia during the 1st century BC and gradually spread across the Roman world, between the 1st century BC and the 1st century AD. These ceramic coatings generally have high amounts of Pb (45–60% PbO), an alkali (Na 2 O-K 2 O) content less than 2% and an alumina content (Al 2 O 3 ) between 2 and 7% [4]. The raw material used for lead glaze was galena (PbS) or litharge (PbO). The glazes were directly applied on the surface of ceramic ar- tifacts, in the form of a water suspension or as a “frit” (crushed glass) [4,6]. Walton and Tite [7] described two methods of glazed coating production: the frst method involved the application of Pb oxides on non-calcareous body pottery, and the second method consisted of a mixture of Pb oxides and quartz on calcareous ceramic pottery. These authors reported that during the Roman Empire the main production centers of lead glazed pottery were located in Gaul (nowa- days France), Italy, Serbia and Romania, suggesting that the technolo- gical knowledge migrated from the Hellenistic to the Roman world [7]. Therefore, investigating the provenance of the raw materials involved in glaze production, it is important to reconstruct the main trade routes that disseminated this technology. The use of lead isotope ratios as a tool to investigate the provenance of metallic artifacts in archaeology started in the mid-1960s [8,9]. The frst provenance studies were on ancient coins, for which both trace https://doi.org/10.1016/j.microc.2019.104519 Received 2 July 2019; Received in revised form 9 December 2019; Accepted 9 December 2019 ⁎ Corresponding author. E-mail address: laura.medeghini@uniroma1.it (L. Medeghini). Microchemical Journal 154 (2020) 104519 Available online 11 December 2019 0026-265X/ © 2019 Elsevier B.V. All rights reserved. T