Ancient glasses deriving from differing environments (marine and ground) and areas (Mediterranean and Continental) have been investigated to understand their weathering processes. Although the glass technologies, developed in various ways, and the differing compositions of the glasses from the two areas, have generated differing durabilities, the weathering features of both typologies of glass are identical. Therefore, the corrosion phenomena are due to the action of water, and they are not related to the sample microclimate. Data have been collected using optical microscopy, RGA and surface analysis techniques: XPS, ESEM and SIMS. [ABSTRACT FROM AUTHOR]