Clays from the Bay of Naples (Italy): new insight on ancient and traditional ceramics

Abstract

The features of two clayey raw materials from the Bay of Naples and their fired products were investigated via minero-petrographic and physical techniques. Clay preparation and firing dynamics were performed following a process similar to that performed by ancient and traditional potters. A high-CaO marine clay from Ischia was mixed with different amounts of volcanic temper in order to replicate most common ware. These mixtures show a fair mechanical resistance starting from relatively low firing temperatures (>850ºC). The addition of temper resulted in different technological characteristics. A low-CaO weathered pyroclastics from the Sorrento Peninsula was prepared to simulate heat resistant and refractory ceramics. Fired products are characterised by a less resistant ceramic body up to 1000ºC compared to Ischia ceramics. Despite worse strength these ceramics show a porous structure, yielding better refractory performances.