Patrizia Davit

Technological Characterization of Campanian Pottery of Type A, B and C and of Regional Products from Ancient Calabria (Southern Italy)

Sherds of Campanian pottery were studied by SEM-EDX. SEM images show that slips of Campana C are scarcely sintered and are thicker than the well vitrified coatings of Campana A and B and imitations of Campana B. Slips of products with a grey slip on a grey body are very thin and well vitrified. EDX analyses indicate that slips are richer in aluminium and iron, and poorer in silicon and calcium, with respect to the bodies, Higher potassium is also found in all of the coatings except those of Campana A. Here relatively high sodium makes the total alkalis comparable with those of the other products, except Campana C, where it is somewhat lower, Measurement of thermal expansion and X-ray powder diffractograms suggest that firing temperatures were mostly in excess of 900°C, but some samples of Campana C seem to have been fired below 800°C.

Glass Fragments from the Crypta Balbi in Rome: the Composition of Eighth‐century Fragments

Eighth-century glass fragments from the Crypta Balbi in Rome were analysed by inductively coupled plasma emission spectroscopy. The samples included fragments of artefacts as well as ingots of raw glass and wasters. All the fragments proved to be soda-lime glasses. Manganese-to-iron atomic ratios are highly variable and determine the colour of a large number of samples. Fairly high copper contents, generally associated with relatively high amounts of antimony and lead, were detected in some green and blue-green samples: this suggests recycling of glass in the form of opaque mosaic tesserae. All three elements are higher in eighth-century than in previously analysed seventh-century fragments. This may indicate greater recourse to recycled glass, related to a reduction in trade exchanges in the Mediterranean.

Acidic and Basic Sites in Nax aNd Nay fAujasites Investigated By Nh3, Co2 and Co Molecular Probes

The acid-base properties of samples of NaY and NaX faujasites have been investigated by adsorbing different probe molecules and measuring IR spectra. In the case of the NaY sample, only Na+ ions were found to be involved in the adsorption of CO2 and CO, confirming the overwhelming Lewis acid character of this material. In contrast, carbonate-like species were formed by adsorbing carbon dioxide on the NaX sample, due to the reaction of basic framework oxygen atoms with CO2 molecules polarised on neighbour Na+ ions. The spectroscopic analysis of NaX also showed evidence of Brønsted acid hydroxyls and OH groups bonded to extra-framework Al atoms. Ammonia adsorption revealed that the amount of Brønsted acid hydroxyls is significantly lower than the Lewis acid Na+ countercations. Moreover, small oxide particles, carrying carbonate-like species on their surface, are present in the zeolitic cavities. These particles could be responsible for the basic reactivity towards CO observed after outgassing the NaX sample at high temperature.

Mineralogical and chemical composition of transport amphorae excavated at Locri Epizephiri (southern Italy)

Abstract Mineralogical, petrographic and chemical analyses were performed on sherds of transport amphorae (VI–III century B.C.) excavated at Locri Epizephiri, as well as on specimens of local manufacture. Examination of thin sections by the polarizing microscope and of X-ray powder diffraction patterns suggested that most of the amphorae could be assigned to local workshops since fossils and minerals as well as rock fragments are compatible with the crystalline basement of the Calabrian-Peloritanian arc. Chemical analysis, performed by ICP and flame atomic emission spectroscopy followed by multivariate treatment of data, further suggested that three groups of composition may gather most of the amphorae and the local reference products. These results point to a wide local production of transport amphorae in Locri, thus indicating that the ancient town was self-sufficient in producing agricultural foodstuffs, with limited dependence on imported goods.

The “Coptic” textiles of the “Museo Egizio” in Torino (Italy): a focus on dyes through a multi-technique approach

The Coptic textile collection of the Museo Egizio in Torino (Italy) has been the object of a broad project aimed at investigating the production techniques, at documenting the conservation state and at reconsidering the attributed age. The collection was also analysed by non-invasive and micro-invasive techniques with the aim of detecting the dyes that have been employed to obtain the colours, in order to complete the set of technological information available for each textile. The data collected in the present work have been compared with published results from other Coptic textile collections, with the aim of highlighting a possible link between the age of the textile and the dyes that were employed. Moreover, the combined use of spectroscopic and chromatographic techniques allowed us to compare the results for the non-invasive and the micro-invasive approaches and to go deeper into the dyeing technology by detecting unexpected combinations of dyes. In particular, the use of a double dyeing with madder and Indian lac dye was revealed in some Roman-Byzantine and Byzantine textiles from the collection.