Nine Roman gold coins under the synchrotron light

Nine Roman gold coins were analysed at Elettra Sincrotrone as part of the COINS (COmo treasure INterdisciplinary Study) project by the University of Turin, University of Milan, University of Pavia, and the Superintendence of Archaeology Fine Arts and Landscape.
They are made of gold, date back to the 5th century A.D., and have spent the last 15 centuries underground, guarded by the walls of an amphora. Then, in September 2018, they could shine again in the sunlight: one thousand coins were found during an excavation, taking the breath away from the archaeologists who found them. This extraordinary discovery is known as the "Como Treasure", and nine of those coins are the protagonists of the experiment carried out few weeks ago in Elettra.
Given the rarity and the extremely high value of these finding, any analysis must preserve their integrity and even the slightest damage must be avoided.
For this reason, the research team, consisting of researchers from the universities of Pavia and Turin and an official archaeologist from the Ministry of Culture (SABAP-CO-LC), chose the XRF beamline.
X-rays are known for their ability to analyse materials of various kinds without altering their structure, but not all sources are the same. Indeed synchrotron sources such as Elettra, combined with the XRF beamline instrumentation, can in fact analyse the composition of coins by identifiying even those elements having  concentrations that are undetectable by conventional X-ray sources.