Comprehensive approach for the conservation of the mosaic floor of the Saints Cosmas and Damian church of Jerash Greco-Roman city

The mosaic floor of Cosmas and Damian Church was unearthed by the Yale University expedition in 1928-1929, and since then the mosaic floor has been exposed to the different agents of deterioration. The article provides a comprehensive approach with six phases suggested to minimize the deterioration: documentation, deterioration diagnostics, treatment, conservation and management. An analysis of physical properties of the tesserae through petrographic techniques was attempted to understand and thus conserve the mosaic floors’ materials. The use of diluted ammonia-based solvent was proved to be the best workable treatment to remove the microorganism and to hinder the diffusion of the colonization of lichens on the mosaic floors in Jerash. With modification to suit local parameters, this comprehensive approach can be also applied to treat and conserve other mosaic floors in the area.