Building stones of the convent of Trinitarias Descalzas and San Ildefonso in Madrid (Spain)

Abstract

Miguel de Cervantes Saavedra was laid to rest at the Convent of Trinitarias Descalzas and San Ildefonso (Madrid) in 1616. The original convent dates back to 1612. In 1673 construction of the church commenced. Once the church was completed in 1696, the reconstruction of the convent began, acquiring its current form. The stones used in the construction of this convent are those which were traditionally used in Madrid. It features flint masonry sockets on the facades, which face towards the streets of Lope de Vega and Cuesta de las Trinitarias. The rest of the sockets were built with granite ashlars (Piedra Berroqueña), with crystal-size from fine to medium. Granite is also located in the arcades of the main facade and is present in other elements such as the jambs and lintels. The ornamental part of the building is carved from dolomitic stone, and shows loss of cohesion and soiling. Scaling, saline efflorescence, anthropic decay, microcracks (detected by fluorescence microscopy techniques) is present in the granite. The flint stone are the best preserved. Knowledge of stones, historic quarries and causes of stone decay are necessary for conservation interventions, especially for reintegration of damaged ashlars and replacing the original stone with compatible materials. Madrid flint comes from ancient quarries near Madrid. Based on its petrological characteristics, the granite was extracted from Moralzarzal quarries, while the dolomitic stone extracted corresponds to the Cretaceous formations of Madrid, called Redueña stone. The study of historical documentation of building stones complemented by petrographic and fractographical techniques provides very useful data for the dating of historic buildings, as well as other disciplines such as history, archeology, restoration, fine arts, architecture and forensic science.