Ricerc@Sapienza

A group of orichalcum Roman coins, from private collections, have been studied for this research. Numismatic examination indicated that they are asses, sestertium and dupondius, minted from Julius Caesar to Nero. Orichalcum is an ancient copper based alloy with a variable percentage of zinc.
The aim of this study was to investigate the process of dezincification from the external layers to the core of the samples. Furthermore, the research was aimed to disclose the real chemical composition of the orichalcum alloy.

A collection of ancient Roman orichalcum coins, i.e., a copper-zinc alloy, minted under the reigns from Caesar to Domitianus, have been characterised using scanning electron microscopy (SEM-EDS) and electron microprobe analysis (EMPA). We studied, for the first time, coins emitted by Romans after the reforms of Augustus (23 B.C.) and Nero (63-64 A.D). These coins, consisting of asses, sestertii, dupondii and semisses, were analysed using non- and invasive analyses, aiming to explore microstructure, corrosive process and to acquire quantitative chemical analysis.

This study is focused on the Phoenician Red Slip Ware, a cultural and chronological marker, unearthed in the archaeological site of Motya. The vessels are dated back from the 8th to early 5th century B.C. The ceramics were investigated using Optical Microscopy (OM), X-ray Powder Diffraction (XRPD), Scanning Electron Microscopy (SEM) and Electron Microprobe Analysis (EMPA).