A new type of cycloaliphatic epoxy resin has given very promising results in the structural consolidation of badly deteriorated magmatic rocks like granites and trachytes, as well as in limestones and marbles. The resin, dissolved in a mixture of organic solvents, is extremely fluid, and can be used for deep impregnation of materials of low porosity, such as granite, but has proven to be particularly successful for the consolidation of very porous rocks such as volcanic tuffs. The formula discussed is both chemically and physically very stable; it has a remarkably low yellowing index, very good mechanical properties, and a low cost. The paper presents the results of laboratory tests as well as of in situ trial treatments. Laboratory tests discussed include water absorption, crystallization and compressive tests, and scanning electron microscopy controls before and after treatments of Vicenza Limestone, Red Verona Marble, Proconnesian Marble, and Troadic Granite samples. The examination of field trials discusses the results of consolidation of monuments of volcanic tuff, Euganean Trachyte, and Egyptian Granite.