SCIENTIFIC ANALYSIS OF ROMAN GLASS FROM AUGUSTA PRAETORIA

Fifty-five fragments of Roman glass from Augusta Praetoria (Aosta, Italy) were analysed by inductively coupled plasma optical emission spectroscopy determining 15 elements (Si, Na, Ca, Al, Fe, Mg, Mn, Ti, Sr, Ba, Cr, Ni, Cu, Co and Pb) on dissolved samples; in addition, potassium was determined by flame atomic absorption spectroscopy. The analytical results indicate that all the fragments, with one exception, are silica-soda-lime glasses; (he exception is a potash glass. Cluster analysis was performed on the analytical data by accounting for either 14 (all the elements searched for but Ni and Pb) or eight elements (after further removal of Si, Fe, Mn, Cr, Cu and Co from the data set). The results obtained indicate that, once colouring and decolouring agents are removed, the classification of the glasses seems to be mainly determined by chronology; separate groups within coeval fragments may indicate different provenances.     

RIETVELD X-RAY DIFFRACTION AND X-RAY FLUORESCENCE ANALYSIS OF AUSTRALIAN ABORIGINAL OCHRES*

Rietveld phase analysis of X-ray powder diffraction patterns and chemical analysis by X-ray fluorescence spectroscopy have been used to characterize a series of red and yellow ochre samples from Aboriginal ochre deposits in South and Western Australia. The ochres were found to have diverse mineralogy, being mixtures of up to seven minerals, and also to have complex trace element signatures. The mineralogical characteristics and geochemistry of the ochres can be used to identify the source quarries. Using this combination of analytieal techniques it may be possible to trace the source of ochres in burial sites and on objects back to the original quarries.     

INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION SPECTROSCOPY ANALYSES OF ROMAN MILITARY COPPER-ALLOY ARTEFACTS FROM THE EXCAVATIONS AT MASADA,ISRAEL*

A selection of Roman military fittings and associated copper-alloy artefacts was analysed by inductively coupled plasma-atomic emission spectroscopy. The method used was a variant on those previously published and gives very good precision and accuracy. The Roman metalwork analysed conforms extremely well to similar artefacts analysed from, contemporaneous European sites and suggests, despite the strongly ‘local’ nature of the Judaean legions, a considerable uniformity of alloying practice within the Roman army during the first century AD.     

A New Methodology for the Provenance of Marble Based on EPR Spectroscopy

Fifteen years of research in investigating the characteristics of the EPR spectra of different types of white marble from several quarries in the Eastern Mediterranean has produced an accumulation of a large number of data, and much experience. Statistical treatment of these EPR data (statistical distributions and parameter correlations), has led to the selection of 10 parameters that are useful for quarry discrimination. Apart from the EPR parameters, the maximum grain size, measured with a stereomicroscope, has been found very useful. Boxplots have been found to be very useful as a first easy visual tool for evaluating the discrimination capacity of each parameter. On the basis of these results, a new methodology for determining the provenance of an archaeological sample was developed in stages, using a different pair or combination of parameters each time. In the first stage, the Penteli, Naxos, Hymettus and Proconnessus quarries are completely separated from each other. However, overlapping occurs between the parameter fields of Paros and Proconnessus, Paros and Hymettus and between the two archaic quarries of Melanes and Apollon on Naxos. If the sample is located in a non‐overlapping area, its provenance is obvious and easily determined. If the sample lies in one of the above three overlapping areas, an additional stage is necessary, in which other parameters are used to eliminate or decrease the overlap. Despite the partial overlapping of Paros with other quarries, the famous Lychnites marble of Paros, which was quarried underground, is clearly distinguished.     

RECONSTRUCTING ANCIENT YEMENI COMMERCIAL ROUTES DURING THE MIDDLE AGES USING STRUCTURAL CHARACTERIZATION OF TERPENOID RESINS*

Following the discovery of items that look like resins at the medieval site of Sharma (Hadramawt coast, Yemen, c. 11th century ad ), chemical investigations were carried out in order to determine their nature and geographic origin. By combining visual observation, infrared spectroscopy, direct inlet electron ionization – mass spectrometry (DI EI–MS) and pyrolysis gas chromatography – mass spectrometry (Py GC–MS) or gas chromatography – mass spectrometry (GC–MS) analyses, it was demonstrated that 84% of the samples were harvested from Hymenaea trees growing in Madagascar and East Africa. Contrary to what was thought previously, frankincense, identified with certainty in only two samples, was thus not the main resin exploited at Sharma. These results are of prime importance for reconsidering the trading routes of resins passing through Sharma, a site that was obviously strongly connected with Africa during the Middle Ages.     

DISTINGUISHING AMBER AND COPAL CLASSES BY PROTON MAGNETIC RESONANCE SPECTROSCOPY

Fossilized resin, or amber, has been examined from 120 worldwide sources by 1D and 2D proton magnetic resonance spectroscopy in solution. These spectra fall into five categories, corresponding to the classes already established by mass spectrometry and carbon‐13 magnetic resonance spectroscopy. The wide availability of this technique provides a straightforward method to classify amber rapidly and inexpensively.     

A MICRO‐RAMAN AND INTERNAL MICROSTRATIGRAPHIC STUDY OF CERAMIC SHERDS FROM THE KILNS OF THE MEDICI CASTLE AT CAFAGGIOLO*

Nine representative sherds from the old (14th–16th century) kilns at the Castle of Cafaggiolo in Tuscany have been analysed by means of internal microstratigraphic analyses and micro‐Raman spectroscopy and classified as follows: six engobed and glazed fragments, of which three are covered with an opaque white, decorated layer, one is marbleized, and two are engobed. The surface of the two engobed sherds, fragments of unfinished products, indicates that at least two firing processes were used. Two samples show characteristics of Byzantine pottery, and three of them can be classified as Islamic ware or maiolica, whilst the other one displays intermediate characteristics. The variety of ceramic wares indicates the presence of craftsmen with differing expertise, and suggests that part of their work was dedicated to experimentation on new ceramic production techniques.