This work presents the results obtained from the evaluation of mortars applied in the elaboration of replicas in the conservation and restoration of artistic and monumental heritage (sculptures and ornamental pieces). Two types of mortars have been studied, using Tosca de Rocafort (a variety of Godella stone) and Bateig (a variety of Novelda stone) stones as fillers: a) mortars using inorganic hydraulic binders, and b) resin bound mortars using polymeric binders. These lithic materials, present in the Valencian Region, can be found in outstanding monuments in the city of Valencia (La Lonja, Cathedral, Serranos Gate, among others) where they exhibit considerable physical, chemical and biological deterioration. In contrast to the case of hydraulic mortars, scientific studies aimed at the optimization of resin bound mortar preparation are rarely found in literature despite the fact that their use is widely extended all over Europe. Similarly, little information concerning these two types of stone materials was found. In this research, values of porosity accessible to water, water absorption, bulk densities and real densities, saturation coefficient and compression and flexion strength have been determined on a series of test specimens prepared with polyester and acrylic resin, as well as lime-gypsum, as binders of the mortars. The experiments performed have led the authors to establish that the studied resin bound mortars have higher stability and resistance properties in comparison to those made of hydraulic mortars and natural stone.