Characterization of bronze Roman coins of the fifth century called nummi through different analytical techniques

Introduction Coins are widely studied in archaeometry because they provide a lot of information on the social, economical, and technological history of the people and territories, which they are related to. In fact, they were generally struck, made of a well controlled alloy by a known mint, and sometimes they also have a date of issue. Other references can be found in ancient documents and, as been done for Roman coins, their typology, metrology, and chronology have already been well studied [1-3]. However, the lack of documentation on the minting technological processes (casting, mechanical working, heat treatment) requires chemical and metallurgical investigation to obtain a detailed description of the coinage production. Metallography is an important tool that provides useful data on the quality of the used alloy and the thermo-mechanical history of the sample, which are strongly related to the production technology. A multidisciplinary approach to the problem of these issues may solve, above all through microstructural analyses, some general questions on coin production, chronology and official/unofficial minting, opening new perspectives to the study of these materials. ... ...