Deposition of particulate matter on stone surfaces: An experimental verification of its effects on Carrata marble

Carrata marble samples have been exposed in Milan and Aosta to verify the correlation between decay and pollution. Gravimetric, colorimetric and chemical analyses have been carried out every 6 months. The deposition of particulate matter causes a decay both in Milan and Aosta, despite the difference in the amount of deposition. A decay parameter has been calculated from the results of chemical and gravimetrical analyses: it is a useful parameter to evaluate the effects of the environment on the stone.