A new method of reinforcing historic stone objects employs stable silica. The method consists in the saturation of the stone with water glass and with the addition of special catalysts which bring about a production of insoluble crystal silica in the pores. This transformation exerts a major effect upon mechanical strength and resistance to aging. In order to evaluate the proposed method objectively, the reinforced samples have been studied in detail, with attention focused upon the following analyses; the content of reinforcing substances and their distribution in the structure of the samples, the degree of capillarity and water absorption, mechanical strength, the content of soluble salts in water and their ability to produce efflorescences and brine about the destruction of the sample. Results of the studies are presented; the conclusion is reached that the method has not shown the advantages ascribed to it and, therefore, should not be employed in the conservation treatment of stone historic objects.