Doris Möncke, Dr. rer. nat. habil., FSGT has been working as a glass scientist since she obtained her doctoral dissertation on irradiation induced defects in glasses 2001 at the Otto Schott Institute of Glass Chemistry in Jena. Trained as a chemist, she studied polyvalent ions and structure property correlations in glasses. Applications of her research include optical and technological important glasses for biomedical or high strength mechanical applications, but extend also to art and archaeometry. Doris has first-hand experience in the structural studies of glasses by optical, IR and Raman spectroscopy, having worked five years at the National Hellenic Research Foundation (NHRF) in Athens, Greece, where her interest in archaeometry and ancient glass technology was kindled. In 2017, Doris obtained her habilitation from Jena University, focusing on the role of cations in glasses (from dopants to network former). Doris has worked since as docent and researcher at Alfred University (NY, US) the Universidade Federal de São Carlos (Brazil), and is currently guest professor at Linnæus University (Sweden).
Archaeometric evidence for glass melting in Sweden in the mid 13th century
Bo Jonson1, Anna Ihr2, & Doris Möncke1*
1Department of Building and Energy Technology – glass group. Linnæus University, Växjö, Sweden
2Department of Historical Studies, University of Gothenburg, Gothenburg, Sweden
The history of glass usage and possible the manufacturing of glasses in Sweden has been investigated so far only to a small extent, especially in terms of chemical analysis of vitreous objects. Here, we want to present an archaeometric study of glass findings from the medieval settlement of Lödöse, which existed mainly through the 13th to 15th century. The town was a centre for trade – mostly with the European continent – minting and craftsmanship as well as a priory of the black friars that was established in mid-13th century .
Recent excavations in the town of Lödöse found remnants of a brick kiln. C14 analysis dated the findings to the period of around 1260 AD. As building material in the kiln and in stratigraphic older layers below it, a crystalline material was found together with a glassy material or possibly a slag. The glassy material was found to be too low in its content of carbon to originate from the smelting of minerals to metal in a blast furnace. Chemical analysis found the excavated glass to consist of approximately 3 % Na2O, 3% K2O, 4% MgO, 18% CaO, 11 % Al2O3, 4 % Fe2O3, 1% P2O5 and 55 % SiO2 (in wt-%).
Additionally, samples of coloured window glass from the medieval priory church, which was partly excavated around 1920, were chemically analysed by IPS. The window glass composition were found vary, but a general composition was around 1 % Na2O, 13% K2O, 5% MgO, 24% CaO, 2 % Al2O3, <1 % Fe2O3, 5% P2O5 and 46 % SiO2 (in wt-%). XRF analysis was used to probe the chemical composition of glass objects and glazed bricks kept in the museum of Lödöse.
The fingerprints of trace elements in the recently excavated glassy materials compared with church windows differ significantly, indicating different raw material sources and thus different melting sites for the respective glasses. The analytical results will be discussed in the context if the excavated glassy materials should be interpreted as a waste products or as intentionally made glasses. The latter would mean that we can confirm evidence for glass melting around 300 years earlier than previously known for Scandinavia
 A. Ihr, “Becoming Vitrified – Kilns, Furnaces and High Temperature Production”, Gotarc Series B. Gothenburg Arcaheological Theses 63, 2014