Secondary phosphates in the ceramic materials from Frattesina (Rovigo, North-Eastern Italy)

The pervasive crystallization of secondary phosphates in pores and fractures of numerous potsherds from the archaeological site of Frattesina (Fratta Polesine, Rovigo - North-East Italy) indicates that contamination occurred after burial. The chemical composition of these phases, which are Mg-rich vivianite and mitridatite, shows that sources of phosphorus, calcium, iron and magnesium were locally available and that the precipitation and diagenesis of these minerals were strongly influenced by micro-environmental conditions within the archaeological deposit.