Non-Destructive and Minimally Invasive Analyses of Bronze Seal Boxes from Augusta Raurica by Micro X-Ray Fluorescence Spectrometry, Raman Spectroscopy and FTIR Spectroscopy

Augusta Raurica (Augst) is a vestige of a Roman town near Basel, Switzerland, which was built around the year 15 BC. Between 80 and 270 AD, the town spread to cover a surface of nearly 106 ha, and up to 20,000 inhabitants were living on the southern bank of the River Rhine. The zenith of town construction and activity at this location occurred in a period between the first and the early third century AD. Many remnants of Roman structures have been discovered at Augusta Raurica, such as the recently renovated scenic theatre, an amphitheatre, public baths, temples, private houses, a huge forum, and a 6.5 km aqueduct. More than 1,600,000 objects providing us with information about daily life in the town have been found (Derks and Roymans 2002). One special group of excavated objects consists of seal boxes. The assemblage from the Augst excavation site contains the highest number of bronze seal boxes (140) in the Roman world. Such boxes were used to hold writing tablets, coin purses, etc., for safekeeping, by enclosing these objects with a wax seal. Archaeological and technical questions that have been raised about these bronze seal boxes are the subject of an interdisciplinary project initiated by the archaeologists and conservators of the Roman Museum “Augusta Raurica” together with the scientists of the Laboratory for Conservation Research of the Collections Centre of the Swiss National Museum.