THE NEWLY FOUND CAROLINGIAN TESSERAE OF GERMIGNY-DES-PRÉS

The current church of Germigny-des-Près (Loiret), one of the oldest in France, holds the only carolingian mosaics conserved in situ at the north of the Alps (James 2017). In the 19th century, during the restoration of the building, mosaics were destroyed and other heavily restored. Still, in the eastern apse, the conserved pieces allow us to reach the tesserae and glass productions for a period lacking of evidences.
In addition to the previous work (Van Wersch et al. 2019), materials from the mosaics were analysed in situ with portable methods and, in the summer 2020, excavations on the site brought to light about 40 new glass tesserae. These were analysed by LA-ICP-MS, Pxrf and Raman in order to identify their components and techniques as well as in order to link to newly found artefacts to the remaining mosaics in the church.
The cobalt blue tesserae have a CoO/NiO ratio which is close to those known for the roman period (24 < CoO/NiO < 54) (Gratuze et al., 2018). The high quantity of Sb could also indicate reuse of antique tesserae. Still, as the turquoise cubes, their compositions are not that homogeneous and different recipes could have been used for the cubes with the same colors. Confirmed by the analyses in situ, these probably indicate a supply from various origins. The black appearing tesserae are quite homogeneous with higher traces of plant elements but small amounts of Fe, Co or Mn, not frequent for that type of glass. Finally, the golden tesserae have homogeneous compositions with some peculiarities that may prove a specific production, maybe on demand and for the creation of these particular mosaics.