Authors: Rossella Arletti Simona Quartieri Ian C Freestone
Publish Date: 2012/10/26
Volume: 111, Issue: 1, Pages: 99-108
Abstract
We applied Xray absorption near edge spectroscopy XANES to obtain information on the origin of glass colour of several archaeological samples and on the oxidation conditions employed during their production We studied a series of selected glass fragments—mainly from excavated primary and secondary production centres and dated to the first millennium AD—containing iron and manganese in a wide compositional range In most of the studied samples iron is rather oxidised while Mn Kedge XANES data show that in all the studied glasses Mn is mainly present in its reduced form predominantly 2+ with the possible subordinate presence of Mn3+ The most oxidised samples are the HIMT high iron manganese titanium glasses while the less oxidised ones belong to the primary natron glass series from the early Islamic tank furnaces at Bet Eliezer Israel and to the series coming from a Roman glass workshop excavated in Basinghall Street London In these glasses iron is approximately equally distributed over the 2+ and 3+ oxidation states The XANES analyses of two glasses which had been deliberately decolourized using Sb and Mnbased decolourizers demonstrate that Sb is more effective than Mn as oxidant
Keywords: