# Silver Isotopes in Silver Suggest Phoenician Innovation in Metal Production
## 1 Introduction
They supplied silver to the Levant from the Taurus mountains in Anatolia, and from Iglesiente in south-west Sardinia and later from the Pyrite Belt in Iberia [6]. These long voyages lasted for ~300 years, through most of the Iron Age II A-C (~950-630 BCE); [31]. The quantities of silver brought by the Phoenicians to the Levant during this period ('the Phoenician period') greatly exceeded those traded in earlier and later periods [6; 25; 31]. Finally, at the very end of the Iron Age (~630-586 BCE), East-Greek merchants took over the supply of silver, bringing silver and copper from Laurion and Siphnos in the Aegean to the Levant and Egypt [31; 32; 33]. While the changing origins of silver found in the Levant have been widely discussed, we still have limited knowledge regarding the development of silver production practices and the exploitation of new ones. Mines are often illusive for this purpose, as later exploitations have overridden ancient exploitation attempts (e.g., [1; 2]). Here we approached this question from the artifact point of view, based on silver isotopes. Silver isotope (SI) measurements have several applications in the study of ore formation processes [34; 35; 36]. According to [36], \"isotopic fractionation of silver occurs (a) during low-temperature remobilization of Ag associated with redox reactions in the supergene (weathering) environment, and (b) among Ag-bearing mineral phases, including Ag-halides (bromargyrite, chlorargyrite, iodargyrite, boleite and pseudoboleite) and As-bearing sulfosalts (e.g., enargite, tenntinite, proustite and polybasite).\" As a result, the relative abundance of Ag isotopes sometimes varies within the same mine, from deep primary ores to supergene oxidized minerals or during different phases of mineralization. They also change with the nature of the ore deposits, e.g., hydrothermal versus sedimentary [34; 36]. Several studies investigated the Ag isotopic variability of various hypogene and supergene silver-bearing minerals (including silver sulfides, sulfosalts, chlorides, hypo  
Figure 2: Silver hoards analyzed in this study: (**a**) silver from the Shiloh hoard (without pendant), courtesy of the Israel Museum, Jerusalem. (**b**) Silver from hoard Tell el-’Ajjul 1312, courtesy of the Israel Antiquities Authority (Photo: [PERSON]). (**c**) The Dor silver hoard image, © The Israel Museum by [PERSON] (photographer) and the Tel Dor Expedition. (**d**) The ‘Akko silver hoard image courtesy of [PERSON] (photographer). (**e**) The ‘Ein Hofez silver hoard image courtesy of the Israel Antiquities Authority, by [PERSON] (photographer). (**f**) The ‘Arad silver hoard, courtesy of the Institute of Archaeology, Tel Aviv University (photographed by [PERSON]). (**g**) Selected items from ‘Ein Gedi hoard, © The Israel Museum, Jerusalem. gene native silver and supergene native silver) from a large range of deposits and districts (e.g., [34; 36; 37; 38]). No systematic Ag isotopic composition appears to characterize a specific type of deposit, geographic location, or mineralization age (see [36]). The isotopic compositions of Ag are often measured as a relative difference between a sample and a mesured standard. They are expressed as \(\varepsilon^{109}\)Ag (\(\varepsilon^{109}\)Ag = 10,000 \(\times\) {(\(10^{19}\)Ag/\(10^{7}\)Ag)sample - (\(10^{19}\)Ag/\(10^{7}\)Ag)standard}/(10^{19}\)Ag/\(10^{7}\)Ag)standard; [37; 39; 40]; see more below). Sometimes, the \(\delta^{109}\)Ag notation is used instead, where \(18^{109}\)Ag = 10 \(\times\)\(\varepsilon^{109}\)Ag [34; 36]. [PERSON] et al. [34] and [PERSON] et al. [36] showed that worldwide, hypogene native Ag and acanthite/argentite (Ag\({}_{2}\)S) Ag form a tight cluster that the supergene (supergene native Ag and Ag sulfosalts) data overlie and flank: The hypogene deposits, formed by high-temperature mineralization processes, have values that cluster around 0% \({}^{109}\)Ag (with a range of \(-4\)\(\varepsilon^{109}\)Ag to \(+\)\(\varepsilon^{109}\)Ag, namely \(\pm\)0.4 \(\delta^{109}\)Ag).