Ricerc@Sapienza

Metal artifacts are among the most common materials in the Cultural Heritage as they have been used in several fields of everyday life. The study of composition of alloy and its patina in archaeological metallic objects can provide indications about the metal provenance and the involved manufacturing procedures, leading to important conclusions regarding the state of conservation, trade routes and technological background. In our case, coins are important for studying provenance materials, dating, minting and corrosion processes as well as the stratigraphy of the archaeological sites.
The aim of this proposal is to investigate the microstructure and the composition of the alloy with a micro-invasive approach using FIB-FESEM-EDX along with traditional techniques (Raman spectroscopy, EMPA). Commonly, to investigate the composition of metal core are necessary the application of invasive and destructive techniques, therefore the developing a method with minimal damage of artifact can be of a great interest. FIB-FESEM-EDX analysis provides information about the composition, structure and thickness of the metal patina as well as the composition and microstructure of the metallic core without the need to dissect the sample to investigate deeper layers. Recently, FIB-FESEM-EDX was used as a complementary technique but it is never been applied systematically on a large set of samples. In addition, the comparison with EMPA data will be innovative and essential for the validation of the technique. Moreover, crossing the information coming from other techniques allows understanding the technological aspects of minting. As a result, FIB-FESEM-EDX features yield information for the diagnostic, authentication, technologies and historical context in which the coins were produced.