Surface analytical techniques such as scanning electron microscopy in combination with energy dispersive x-ray microanalysis (SEM/EDX) and secondary ion mass spectrometry (SIMS) were applied to characterise the corrosion phenomena occurring on medieval stained glass of Austrian provenance. Depending on the chemical composition and particularly on the silica content of the glass crusted, pitted and apparently unweathered glass surfaces could be observed. A leached layer was formed on all glass surfaces due to an ion exchange process occurring during the weathering, where potassium and calcium of the glass were replaced by hydrogen bearing species from the moist air. Leaching experiments were carried out on ground and polished specimens of model glass with a chemical composition similar to the medieval glass objects.
