Recent investigations of early Roman cameo glass : Part 2. X-ray fluorescence analyses induced by Synchrotron radiation

Abstract

The elemental composition of 14 Roman cameo glass fragments was measured quantitatively b y X-ray fluorescence analysis induced by synchrotron radiation. The study was intended to learn more about the possible manufacturing techniques of these glasses. In the white cameo decor of nine fragments all belonging to vessels a higher lead oxide concentration was detected compared to the colored body. In contrast, lead oxide is not enhanced in the remaining five fragments from cameo disks or plates. The higher concentrations may be interpreted as flux added to lower the melting temperature of the white cameo layers of the vessels, thus supporting the recent hypothesis that these cameo vessels were manufactured with the help of a mold on a turning wheel, which had not to be used for the production of cameo plates.