Search

Ceramic sherds from approximately 20 samples of lead-glazed tableware, recovered from diverse archaeological sites, including three repurposed storage pits transformed into dumpsters within the medieval city of Santarém (13th–14th century), underwent a meticulous examination. This investigation utilised techniques such as micro-Raman, ground-state diffuse reflectance absorption, and X-ray fluorescence spectroscopies, in addition to X-ray diffraction and stereomicroscopy. A parallel study was conducted on contemporaneous European ceramics (glazed sherds) sourced from archaeological sites dating back to the 13th–15th centuries in Saintonge (France), Ardenne, Zomergem, and Bruges (Belgium), as well as Surrey–Hampshire, Kingston, and Cheam (England). The first premise for comparing the Santarem samples with European production locations was their frequent commercial relations with Portugal and the frequency of these productions being found in Portugal. The colour of the ceramic bodies is predominantly white or whitish, with a few exhibiting a vivid red hue. Analyses of the fabric, mineralogical, and elemental composition of the sherds suggest that the majority of Santarém's glazed ceramics were locally or regionally produced, potentially derived from a Pliocene kaolin-rich sand formation. However, this conclusion is not supported by the absence of discovered lead glaze kilns or workshops in Santarém for the late Middle Ages. [ABSTRACT FROM AUTHOR]

Blue‐on‐blue (‘berettino’) sherds have appeared in numerous production and consumption archaeological excavations in Lisbon and other archaeological sites in Portugal (dated from the mid‐16th century to the beginning of the 17th century). The abundance of this interesting faience led us to compare it with similar pottery from other well‐known production centres in Italy, namely Liguria (Savona and Albisola), Spain (the Triana kilns) and the Low Countries. Differences in the diffraction patterns of the sherds' pastes from the four countries were observed. In most samples, cobalt blue silicate (cobalt olivine) was identified in the dark blue or light blue glazes through the use of micro‐Raman spectroscopy and diffuse reflectance spectra. A remarkable difference in the calcite contents of the Lisbon and Seville pottery sherds was observed, in accordance with previous observations of high calcite contents of Seville ceramics. A comparison was also made for all of the blue‐on‐blue sherds studied here with many other 16th–17th century sherds from Lisbon using bivariate plots of K/Si versus Ca/Si. Lisbon and Seville pottery behave very differently, whereas sherds from Italy and the Low Countries occupy intermediate positions. [ABSTRACT FROM AUTHOR]