Low-durability glass samples were exposed, sheltered from the rain, to atmospheric pollution in Paris. They underwent essentially two surface modifications. First, a leaching process took place, also in the absence of rain water. The second modification consisted of depositing atmospheric particles and the appearance of new crystallisation on the glass surface. Analytical Scanning Electron Microscopy (ASEM) was used to study the morphology and chemical composition of the new crystallisation. Their cationic composition ensues directly from the underlying glass chemical composition. They are mainly constituted of sulphates. This suggests strongly the intervention of atmospheric sulphur dioxide. The mineralogy of the crystallisation evolves with the advance of glass weathering state. Their size has the tendency to increase with exposure to time.
