The stucco work of Giacomo Serpotta and the Serpotta school. Constitutive materials, degradation and decay

Giacomo Serpotta. (1656-1732) was the major figure of a school of stucco work which was growing and developing in Palermo in the course of several decades towards the end of the 17(th) century. This paper presents some preliminary results of a wide and systematic comparative study, aimed at investigation of the compositional and textural characteristics of the stucco, and of the techniques of the modeling and finishing of its surfaces, by means both of measurements of physico-chemical properties of the materials and of their mineralogical and petrographic characterization. The opportunity for such a study was made available by the launching of the "Progetto Serpotta" by the Soprintendenza dei Beni Ambientali e Culturali di Palermo. This project is aimed at the restoration and conservation of most of the Serpotta school stucco works. The project offers a unique opportunity to extract samplings from the entire cycle of works prior to restoration. Moreover, the study of the stucco's material composition serves as an aid in better understanding the nature and the causes of degradation and decay, which in many cases have seriously damaged the works.