EPMA - WDS mapping: a new approach to the investigation of glass weathering

This investigation proposes a new approach to the study of glass weathering through EPMA-WDS elemental mapping. In this study EPMA-WDS maps resulted helpful to visualize the morphology of weathered glass surfaces through the distribution of the content of the representative elements. They allowed, in association with SEM-EDS analysis, to identify the presence of a silica-rich leached layer alkali depleted and some neocrystallization compounds on the surface of the glass sample. These effects can be ascribed to hydrolytic attack to the glass by ion exchange reactions (leaching) between the glass network modifying ions (Na+, K+, Ca2+, Mg2+) and the water H3O+. EPMA-WDS tomography allowed to obtain clear and detailed graphic representations of the weathering morphology on large areas and to characterize the elements and some their related compounds involved in the alteration processes.