TIN AND TINNED DRESS ACCESSORIES FROM MEDIEVAL WROCŁAW (SW POLAND). X-RAY FLUORESCENCE INVESTIGATIONS

Abstract

Introduction Most of what we know about medieval clothing elements and jewellery is from portraits, pictures in manuscripts and artefacts from museum collections. However, this knowledge is focused on precious accessories (and jewellery) that adorned knights and nobles. It was nevertheless important for all social groups to look fashionable and to wear jewellery. To the women and men of the Middle Ages dress elements were not only the determinant of social status, but had a religious context as well. The jewellery motifs were often devotional, e.g. crosses and pilgrims' badges (often worn by men on their hats). Women wore pendants, finger rings, belts and brooches, which were often wedding gifts (Kupstas 2000). Clothing accessories were made from very different metals; noble metals (gold and silver) were intended for wealthy men and cheaper metals for the others. The raw material used to produce the latter ones was bronze, tin, lead and/or lead-tin alloy (Kocka-Krenz 1982; Egan & Pritchard 2008). The imitation of noble jewellery is quite intriguing and will be discussed in this paper. After their conservation, several artefacts were selected for detailed studies: jewellery, dress accessories and tools. They were found during an archaeological excavation in the New Market Square in Wroclaw, SW Poland. The excavation was connected with the construction of an underground car park, which covered nearly 4000 [m.sub.2] in the southern part of the square. The research team, composed of staff and graduate students of several Polish universities (mainly the University of Wroclaw) was led by Professor Jerzy Piekalski. The main excavation took place from September 2010 to December 2012. The New Market Square is located in the eastern part of the Old Town of Wroclaw. It has a long and varied history, bursting with the rich remains of the past in the form of cultural strata. Previous studies of medieval archaeology in Wroclaw indicate that the beginnings of settlement land use are related to the 11th-12th century and were in the close vicinity of the castle on Cathedral Island. The archaeological and architectural study aimed to determine the true nature of craft production, as well as the layout of the New Market Square in the context of medieval Wroclaw. The huge collection of artefacts (11,838 in total, some compact groups of or single ones) is useful in the study of the material culture of medieval Wroclaw, as well as its external contacts (Bonar et al. 2013). The condition of the selected artefacts retrieved from archaeological layers was different (specimens covered by corrosion and layers of impurities, sometimes without metallic cores), which made the identification of tin/tinned artefacts difficult. The state of preservation of metal artefacts is a well recognized topic in archaeology and has been the subject of previous papers discussing soil effects on metal objects, e.g. Gerwin & Baumhauer (2000) and Neff et al. (2005). Therefore, artefact conservation prior to archaeometric investigations is very important. Because of the great historical value of the objects in these and previous investigations, there is a need to use non-destructive analytical methods (Bugoi et al. 1999; Janssens et al. 2000). There are many suitable methods that may be applied in archaeometry: neutron activation analysis (NAA), proton-inducted x-ray emission (PIXE), laser induced breakdown spectroscopy (LIBS) or many types of X-ray spectrometry (X-ray fluorescence (XRF) or scanning electron microscopy with energy dispersive X-ray detection (SEM-EDX)). Many research groups use such analytical techniques, e.g. Linke & Schreiner 2000; Lazic et al. 2005; Smit & Semrov 2006; VlachouMogire et al. 2007. The appropriate techniques should be universal, rapid and not too expensive for the institutions that take care of artefacts and store them (e.g. museums, universities and institutes). X-ray fluorescence is one of the aforementioned methods that are often applied in archaeometry projects (Milazzo 2004; Giumlia-Mair 2005). …