Geochemical characterization of bricks and terracottas used in historical monuments in Ferrara (Italy): Reference to raw materials and production technique

Materials research applied to archaeological ceramic artefacts has garnered widespread interest among scientists, architects, engineers, and archaeologists focused on safeguarding architectural heritage. These ancient structures within historic city centers encapsulate the distinctive history and visual essence of each city across different eras. Assessing both old and new materials following damage to these historical edifices becomes crucial for predicting their behaviour during restoration. This endeavour not only aims to analyze and preserve these artifacts but also aims to explore the knowledge and craftsmanship involved in their creation and use. Characterizing building materials primarily targets preservation and restoration goals, encompassing the origins of historical raw materials, understanding archaeological artifact changes, determining original firing methods, and reconstructing manufacturing technologies. Bricks and ceramics, resembling fired artificial rocks, retain geological imprints from their claystone origins, impacted by local geological settings influencing material availability and building techniques. Take, for instance, Ferrara, a Medieval city in Northeast Italy, strategically positioned between the Adriatic Sea and the Po alluvial plain. Its prosperity during the Renaissance under the Estense family was bolstered by extensive modifications to the city, predominantly utilizing locally abundant silico-clastic sediments for construction.

The focus of this research on historical bricks and terracotta decorations from prominent Medieval and Renaissance buildings in Ferrara is to understand the composition of these ancient materials to aid in planning effective restoration treatments, identifying causes of decay, selecting suitable replacement materials, and avoiding incorrect restoration choices. Analyzing the chemical and geological attributes of these materials provides valuable insights into their manufacturing techniques and origins. Moreover, by comparing obtained data with regional sediment records, it has been possible to ascertain the nature and sources of the original raw materials.