Elemental composition and microstructure of early bronze age and medieval tin slags

The elemental composition and the internal structure of two slag samples have been analyzed and compared using scanning electron microscopy-wavelength dispersive spectrometry and secondary ion mass spectrometry. The first sample studied is a vitreous accretion found on a ceramic crucible sherd, which originates from an Early Bronze Age site in the Kestel/Goltepe area of Anatolia. The intention for examining this glassy-looking material was to verify whether it corresponds in composition to a tin slag. The results of these measurements form part of a research project involving the search for ancient tin production in Turkey and have a direct relevance on the study of tin sources in the near East. Kestel/Goltepe is presumably the first local tin source found in the Anatolian area and in view of this, the vitreous accretion is compared with a medieval tin slag from a more distant source: the Crift Farm in Cornwall, UK. Results of the present study show that both samples are composed of silicates, each with different admixtures of oxides and metals and confirm that the Anatolian crucible accretion corresponds in composition to a typical metallic tin slag.