In the present work microstructural and chemical analysis of tin and slag that resulted from three smelting experiments reconstructing prehistoric conditions are presented. Cassiterite ores were collected from northwestern (NW) Iberian deposits and were smelted in a small open pit. Results show that the loss in tin can be very high, up to 80%, mainly as a result of volatilization of Sn species. The experiments show that using handmade leather bag bellows and clay tuyeres, temperatures can easily reach >1200°C. The tin produced was a very pure (Sn) solid solution, with the presence of dispersed inclusions or phases of various composition. These included FeSn and FeSn 2 intermetallics and small metallic W inclusions. Slags could be grouped into three types based on their physical characteristics, and bulk chemical analysis could relate each type as being a product from the reaction of ore material or a product from the reaction with the crucible material. Generally, it was found that in spite of very low recovery rates, the tin produced by this simple technique would have been adequate for a domestic small-scale production. ARTICLE HISTORY

El objeto de este trabajo es revisar las circunstancias de hallazgo de un conjunto de hachas de tope con dos anillas laterales y cono de fundición encontrado en la finca

This paper draws on the study of the prehistoric art site of Penedo Gordo (NW Spain) resulting from a collaborative interdisciplinary research. One of its primary goals was to design and put into practice a multi-analytical protocol for characterising prehistoric rock paintings, combining in situ and laboratory analytical techniques. Thus, following the archaeological assessment of the site, the panels exhibiting red paintings were analysed by colour spectrophotometry and portable Raman spectroscopy. Analytical techniques were applied to a collection of samples exhumed from the excavation that simultaneously took place on site. These included three red accretions on different substrates (compact soil, white quartzite and grey quartzite) and stone fragments representative of the outcrop’s petrographic variability, aiming to determine their mineralogical composition, texture and study the stone-paint boundaries. Moreover, colouring materials exhumed from the excavation and collected in the immediate surroundings of the rock outcrop were analysed in order to scrutinise the provenience rock art’s raw materials. Laboratory analysis consisted of stereomicroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. One of the major outcomes was the discovery of a drop of red pigment preserved in an archaeological layer associated with Late Neolithic/Copper Age material remains.