Integrated analytical methodologies for the evaluation of ceramic mosaic tesserae durability

The durability of some modern ceramic mosaic tesserae exposed to artificial ageing has been evaluated through the correlation of their chemical, mineralogical, petrographic and physical characteristics to the alteration phenomena (generation of efflorescence, increasing of water absorption) observed on the aged samples. Glazed ceramic materials for wall and floor mosaics, coming from two artisan factories of Morocco (Tafza, Ourika and Oulja, Salé), have been tested. Different technologies and methodologies have been used: X-Ray Diffractometry (XRD), optical microscopy on thin sections, Fourier Transformed Infrared Spectroscopy (FT-IR), Environmental Scanning Electron Microscopy (ESEM)-coupled with Energy Dispersive x-ray Spectroscopy (EDS) for the chemical and mineralogical characterization, and ultrasonic propagation velocity test for evaluating physical changes caused by ageing.