MINERO‐PETROGRAPHIC STUDY OF COOKING WARE AND POMPEIAN RED WARE (ROSSO POMPEIANO) FROM CUMA (SOUTHERN ITALY)

Excavations carried out in Cuma by the Centre Jean Bérard archaeologists have uncovered a large quantity of pottery. This study is focused on cooking ware and on internal red‐slip cookware, also known as Pompeian Red Ware (Rosso Pompeiano), dated from the first century bc to the first century ad . A comparison with the minero‐petrographic composition of beach sands collected along the Bay of Naples coastline highlights the provenance of the temper from the Somma‐Vesuvius area, marked by leucite‐bearing scoriae and garnet. Petrochemical analyses allow us to distinguish two main groups of pottery characterized by different technological options based on the amount of temper and on the type of clay. X‐ray diffraction and scanning electron microscope data demonstrate improved accuracy in the production of Rosso Pompeiano, especially with regard to firing control, which was in a prevailing oxidizing atmosphere and in a narrow thermal range, between about 800 and 900°C.     

MAKING COLOURLESS GLASS IN THE ROMAN PERIOD*

This paper discusses the compositional analysis of Roman colourless glass from three sites in Britain. The findings suggest that two broad compositional groups can be identified on the basis of the choice of the initial raw materials selected for glass production, in particular the sand. The largest of these groups is inherently different from the naturally coloured, blue–green glasses of the same period, while the other group is compositionally similar. Further subgroups are apparent on the basis of the decolorizers used. These glass groups are explored in the light of the current theories concerning the organization of glass production in the Roman world.     

ISOTOPES ON THE BEACH,PART 1: STRONTIUM ISOTOPE RATIOS AS A PROVENANCE INDICATOR FOR LIME RAW MATERIALS USED IN ROMAN GLASS‐MAKING

The provenancing of Roman natron glass is one of the most challenging problems in the field of archaeometry. Although the use of Sr and Nd isotope ratios and trace element signatures as an indication of provenance has proven promising, there are still many unknowns. In this study, the influence of the different raw materials on the final Sr isotopic composition of Roman natron glass is examined. It is shown that the ⁸⁷Sr/⁸⁶Sr ratio in natron glass is significantly influenced by the silicate fraction of the sand used and does not always provide a clear indication of the lime source used.     

ISOTOPES ON THE BEACH,PART 2: NEODYMIUM ISOTOPIC ANALYSIS FOR THE PROVENANCING OF ROMAN GLASS‐MAKING

In this study, we have evaluated the applicability of Nd isotopic analysis for the provenancing of Roman glass and we present a database of Nd isotopic compositions of possible sand raw materials from the western Mediterranean, as a means of comparison for the growing number of isotopic studies on ancient glass. The ¹⁴³Nd/¹⁴⁴Nd isotope ratio of sands is a good indicator for their geological (and sometimes geographical) provenance. The use of the isotopic signature of Nd as a proxy for the source of silica in glass is, however, not always straightforward because of the possible overlap of signatures from different suppliers.     

DATA ON 61 CHEMICAL ELEMENTS FOR THE CHARACTERIZATION OF THREE MAJOR GLASS COMPOSITIONS IN LATE ANTIQUITY AND THE MIDDLE AGES

Sets of 20 soda ash, 16 soda lime and 23 wood ash glasses mainly from excavations in Europe were analysed by microprobe and LA–ICP‐MS for 61 elements and are presented as average concentrations with standard deviations. Concentrations of sodium, potassium and magnesium allow the major glass type to be identified. Specific compositions of the raw materials of glass production indicate certain sources, technical processes and ages. Heavy minerals etc. of quartz sands contain rare earth elements (REE) from crustal fractionations that are different for the three major glass types. Accumulations of P, B, Ba, Mn and K in wood from soils by organic processes can characterize glass from certain regions.     

SAND FOR ROMAN GLASS PRODUCTION: AN EXPERIMENTAL AND PHILOLOGICAL STUDY ON SOURCE OF SUPPLY*

This paper reports the results of an experimental study performed on Campanian littoral sand, together with a careful philological analysis of Pliny's text concerning the production of glass using the above sand in order to verify its suitability. Accurate chemical and mineralogical characterization of sand samples and experimental glasses was carried out, proving the unsuitability of sand for glass production in its original state. Taking into account both the results of the philological analysis of Pliny's text and the mineralogical assemblage of the sand, a new hypothesis regarding Roman glass‐making technology is proposed and tested here. The technology implies the production of ‘quartz‐enriched’ sand by means of selective grindings according to the different degrees of hardness and cleavage of the mineralogical phases. Melting experiments, carried out on treated sand and in the temperature range compatible with Roman technology, yielded a glass with composition similar to those of typical Roman glasses. Therefore, new perspectives on the sources of supply of raw materials, hitherto debated, are opened up.