Aesthetic of traditional building ceramics in the Bay of Naples (Southern Italy).

Colorimetry and accelerated aging tests were performed on ceramics prepared using two clays from the Bay of Naples (Ischia and Sorrento Peninsula). Visible-near infrared spectroscopy was applied in order to acquire further information on color and composition of ceramics. Different mix designs and firing dynamics were adopted in order to provide information on the control of aesthetic features of ancient building ceramics. Color depends on firing temperature and physicalchemical composition of the raw materials. Low-CaO concentration provided a more intense reddish hue at high temperatures (over 950 °C). Black core developed in high-CaO ceramic samples fired at low temperatures, except for those containing high temper amounts. Salt crystallization test showed that high-CaO ceramics are more durable starting from relatively low firing temperatures (over 850 °C).