Multidisciplinary approach to investigating graphite coated pottery from early Iron Age Papuk, Croatia: analysis and experimental reproduction

This study investigates the composition and production methods of graphite-coated pottery. Using a range of analytical techniques, researchers examined the chemical and mineralogical makeup of pottery fragments found at the Kaptol archaeological site on Mount Papuk, Croatia. The main goal is to understand how carbon and graphite were deposited on the pottery surface, whether graphite appears only as an external coating or is also mixed into the clay body, and how this affects the pottery’s stability. To explore production techniques, the research also includes experimental reproductions of graphite-coated pottery, focusing on raw materials, methods of applying graphite, and firing conditions (such as temperature and atmosphere). The study is significant because it combines archaeology and materials science, addressing unresolved questions about graphite coating mechanisms while also testing experimental approaches to better explain ancient production methods. Through collaboration with the Arts Academy of Split (Croatia), the team analysed samples of Late Iron Age graphite-coated pottery discovered in a tumulus at Kaptol-Čemernica. The main analytical work was carried out at Ca’ Foscari University of Venice, with additional research and experimental reproduction performed at the University of Split, Faculty of Science. A multi-analytical approach was adopted, including both invasive and non-invasive methods: • FTIR: identified clay minerals such as meta-smectite and meta-kaolinite. • XRF: showed that the coating and clay body share the same elemental composition, though without quantitative results. • Micro-Raman spectroscopy: detected crystalline phases. • TG-DSC: studied thermal transformations of ceramics. • XRD: provided further insight into mineral composition. • SEM-EDS: offered quantitative data on minerals and their crystal structures. By combining archaeometric analysis with experimental archaeology, this research not only clarifies the material science behind graphite-coated pottery but also contributes to broader discussions about prehistoric technological innovation, resource use, and ceramic production methods.