The fingerprint of Greek raw materials in the composition of ancient glasses with “unexpected” isotopic compositions

Abstract In order to discriminate the starting materials of ancient glasses, the isotopic fingerprint of Greek raw materials and fluxes used in glass production were studied. Specifically, measurements of isotope ( 18 O‰) and of chemical composition of halophytic plants, Pikrolimni Natron, sand, chert and limestone samples were conducted. The study proves that the “ Chalastraion nitron ”, mentioned by Pliny the Elder, as flux can be considered for glassmaking and the use of mainly chert and soil quartz of the particular region of Greece can discriminate the starting material by the δ 18 O of the final product. A fishable explanation for the unexpected isotopic compositions of ancient Greek glasses is presented, indicating local production of the raw glass, rather than import from Eastern Mediterranean glassmaking centers.