Combined Microanalytic and Electron Paramagnetic Resonance techniques in archaeometry of ancient glass

The combined use of Electron Microprobe (EMP) and Electron Paramagnetic Resonance (EPR) was applied to the characterisation of ancient glass. The resulting data were complementary and thus very useful for information on both glass composition and the oxidation state of paramagnetic ions, such as Fe 3+ and Mn2+. Our study highlighted the importance of obtaining the abundances (EMP) and oxidation states of the above elements (EPR). These indications represent a new way of looking at ancient glass production and may define several production indicators such as control of kiln atmosphere. Our results show that the value of the oxidising/reducing ratio defines a parameter constraining the colour of worked glass - an aspect which has implications for archaeometric research aiming at reconstructing the history of glass.