Characterization of the alteration processes of historical glasses on the seabed

Glass objects are common in shipwrecks since they are associated with ordinary glassware or com-mercial products. The alteration pathologies of historical glasses from two wrecks from the Mediterra-nean Sea were analyzed to characterize their alteration mechanisms. The results of this research provedthat the alteration layers presented a moderate content of Na2O, similar to the average salinity of theocean, and a high content of Al2O3due to an extremely basic environment during the corrosion process.The biofouling layer protected the glass surfaces. Dark deposits with a high content of MnO wereobserved in the most instable glass.Peer Reviewe