Mössbauer studies of Haltern 70 amphorae from Castro do Vieito, North of Portugal, and of amphora sherds from kilns in the Roman provinces Hispania Baetica and Lusitania

Haltern 70 amphora sherds from Castro do Vieito and from kilns in the Roman provinces Baetica and Lusitania were studied by Mössbauer spectroscopy, EDX and XRD. An amphora whose handle was carefully studied must have been fired reducingly at a temperature of or above about 900°C and cooled in oxidizing conditions in the end. Oxidation and hematite formation went hand in hand, and the amount of hematite formed depended sensitively of the speed of penetration of the oxygen and the cooling rate in the interior of the ceramic body.