# Silver Isotopes in Silver Suggest Phoenician Innovation in Metal Production
## 4 Results
### \(\varepsilon^{109}\)Ag and the Preservation of Silver  
Post-burial weathering processes were found to highly affect the surface of silver items that were found in the sediments of archaeological sites [40]. This was attributed to interactions with groundwater and dissolved organic compounds, which lead to redox transformations of the near-surface silver, causing Ag isotopic fractionation at the surface of silver coins in comparison to their cores [40]. In this study, the silver was presumably sampled from the core of the items rather than the surface; however, as not all items reached a total sum of 100% in their elemental composition, we were concerned that sampling was not always clean of surface corrosion (see Table 1 and [26]). We defined uncorroded silver as items with a total sum of elements that was \(\geq\)90 wt.%. Although most drillings had a total sum of 90-100 wt.%, eight items in this study displayed a lower sum, ranging between 72 and 89 wt.% (Tell el-'Ajjul_5, Tell el-'Ajjul_7, 'Akko_12, 'Akko_2, 'Akko_221, 'Ein Hofez_164,' Ein Hofez_166 and 'Ein Hofez_176). These items are therefore suspected of containing some insoluble corrosion (e.g., AgCI) within the drillings and possibly additional corroded material from the surface of the item. These results suggest that the silver in the hoards from Shiloh, Dor, 'Arad and 'Ein Gedi was better preserved than silver from the hoards of Tell el-'Ajjul,' Akko and 'Ein Hofez. A possible explanation for this difference may be the method in which the silver was stored. Hoarded silver was often stored within cloth bundles or sealed in ceramic vessels, practices that might have reduced the contact between the silver and the local soil. Other hoards that were unsealed may have been more exposed to corrosion and consequentially also to Ag isotopic fractionation on the surface of the items and immediately below it [40]. As hoarded silver is sampled for Ag isotopic composition in this study for the first time, we assess the effect of sealing and bundling on the exposure of the silver to post-depositional weathering processes by comparing contemporaneously sealed and unsealed silver. We attempt to determine whether sealed silver was less exposed to weathering processes than unsealed silver. Here we define four different levels of hoarding (Table 1; for a full description of hoard depositions, see [33]):  
1. Sealed silver: Silver, which was cached in a ceramic vessel and covered by another one, therefore expected to be least exposed to weathering processes in the ground. These include the hoards from Dor (in which the silver was also bundled) and Ein 'Gedi;
2. Bundled silver: Silver hoarded in cloth bundles. The bundle preserves the silver in a tight cluster. The hoard itself may be exposed to underground fluids; however, the bundle and outer silver artifacts may protect the inner silver pieces. This includes the hoard from 'Arad (which was also cached within a ceramic vessel) and Shiloh;
3. Semi-sealed silver: Silver that was not wrapped in a bundle but rather cached in an open, uncovered ceramic vessel. These include the hoards from 'Ein Hofez and 'Akko. The presence of soil within the vessels of the 'Ein Hofez hoard ([PERSON], personal communication) indicates that silver was stored in uncovered ceramic vessels, and thus was exposed to post-depositional weathering processes;
4. Unsealed silver: Silver that was not bundled and not stored in a ceramic vessel but rather buried directly within the ground. One hoard answers this description from Tell el-'Ajjul. The results, as demonstrated in Figure 5, show that unsealed and semi-sealed silver has a wider range of \(\varepsilon^{109}\)Ag values compared with bundled and sealed silver. Semi-sealedsilver, which was hoarded in open ceramic vessels, displays the widest range of \(\varepsilon^{109}\)Ag values.