Copper isotope fractionation during prehistoric smelting of copper sulfides: experimental and analytical data

The project from which the data derived aimed to establish the first systematic study of Cu isotope fractionation during the prehistoric smelting and refining process. For this reason, an experimental approach was used to smelt sulfide copper ore according to reconstructed prehistoric smelting models. The ore was collected by E. Hanning as part of her PhD thesis work from a Bronze Age mining site, the Mitterberg region, Austria (Hanning and Pils 2011) and was made available for the experiments. All starting materials for the experiments such as the natural ore, roasted ore, construction clay, flux, dung (used for the roasting), wood and charcoal (fuel) were natural materials. All firing conditions including the amount of fuel or charging material and the temperatures in the furnaces were recorded, and the experimental procedures were documented in the very detail. In total, 30 experiments were carried out in 4 experimental series. The smelting products, both intermediate products and final products were sampled during or after the respective experiment. Slag, matte and copper metal were the major smelting products. All other materials used in and produced by the experiments were sampled, too. Materials used and produced in the two most promising experimental series with regard to potential Cu isotope fractionation were analyzed. Based on the analytical results, the potential of Cu isotopes as a tool in archaeometallurgical research was systematically evaluated and consequences for the copper isotope application as a provenance tool in archaeometry were identified. The data include the documentation of the experiments, laboratory procedures and analytical methods. An experimental outline was previously published in Rose et al. (2019). Analytical methods applied were ICP-MS (elemental analysis, 80 samples), MC-ICP-MS (copper isotopes, 98 samples), and XRD (phase analysis, 25 samples). The experiments were carried out at the Römisch-Germanisches Zentralmuseum, Labor für Experimentelle Archäologie, Mayen, Germany. Laboratories used for the analytical part of the project were the research laboratories at the Deutsches Bergbau-Museum Bochum and FIERCE (Frankfurt Isotope and Element Research Center), Goethe-University Frankfurt, both Germany. Data were processed and plots created with R (R Core Team 2019) in RStudio®. Data are provided as data tables or text files, the R scripts used to create the time-temperature plots of the smelting experiments are also includ