This paper reports on a study of glass samples found in Baia, Italy. Based on their place of discovery the studied samples should date back to the Roman period. The pieces are crusted & pitted. On the basis of the observation a new hypothesis is proposed for the pitting of glasses. Visual & microscopical observations indicate that the weathering of the glass has led to a multilayer surface sturcture. Weathering was ascribed to the occurrence of hydrolysis and condensation reactions which would have led to layers of gel-like structure & high silica content. Ageing of the reaction layer would have led to formation of pores. The need to relieve stresses could make pore formation preferential at the glass reaction layer interface. As a result, the surface would appear pitted & bubbles should be present in the detached layer when it is sheared off.
