Sienese ˵Archaic″ Majolica: Characterisation of Enamels and Glazes by Analytical-Transmission Electron Microscopy (AEM–TEM).

The Sienese ˵archaic″ majolica coated with enamels and glazes was produced in many workshops within the city from the thirteenth to the end of the sixteenth century AD. This type of ceramics has been the subject of few, but detailed archaeometric studies (Grassi et al. 2003; Fortina et al. 2005). Fortina et al. (2005) reconstructed the production technology of ceramics recovered from the Convent of the Carmine (Siena) according to petrographic and mineralogical evidence. Optical microscopy, X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), and Raman spectroscopy helped reveal the texture and the mineralogical compositions of the ceramic bodies and the coatings, both glaze and enamel. However, it was not possible to properly characterise very fine-grained, newly-formed phases with these micron-scale techniques. Nanometric-size mineral phases grown in artefacts can be recognised by high-resolution techniques, such as analytical-electron, transmission-electron microscopy (AEM–TEM), as it has been done in few recent studies. The characterisation of reaction processes and mineral phases at a nanometric scale led to the determination of technological processes (Mata et al. 2002), mineralogy of coatings in Renaissance pottery (Viti et al. 2003) and of Tuscan black glosses (Giorgetti et al. 2004). [ABSTRACT FROM AUTHOR]