Archaeometric investigations of sgraffito ceramic tiles (fifteenth-sixteenth centuries) recovered from excavations in Udine (North-East Italy)

Most of the Renaissance sgraffito tiles excavated in Udine (Italy) constitute a homogeneous group, the tile body having a CaO/MgO molar ratio ? 3:2. They were produced using a dolomite- and calcite-containing clay fired at 900-950 °C. A small group of samples, with a lower firing temperature and a CaO/MgO ratio ? 2:3, was probably produced in a different factory. Slip and transparent glaze, characterized by optical microscopy and inductively coupled plasma atomic emission spectrometry, are an illite-rich clay and a lead silicate, respectively.