Colour Transformation and Textural Change in Biotite: Some Remarks for the Interpretation of Firing Technology in Greyware Pottery Thin-Sections

Firing is a crucial step in the production of pottery, as it irreversibly transforms clay into ceramic. Clay sintering and subsequent vitrification occur during firing, together with other transformations undergone by specific minerals rock inclusions according to their optical physical properties, including colour. Some these are visible thin-sections might be interpreted technological markers or contribute estimation firing temperatures, although most them poorly documented. In this paper, we approach colour, texture properties that occurred biotite from medieval greyware pottery. Our study considers batch 40 pottery samples Catalonia analysed XRD. According estimated temperature ranges atmospheres, examined behaviour at different 700 °C 1000 means microscopy, considering its size, shape abundance, compared features wider assemblage earthenware. The results obtained interesting, they offer valuable reference for petrographic studies on We discuss potential ceramic petrography way perform more precise refined sample selection further analysis archaeothermometry.