Sasanian glass from Veh Ardašīr: new evidences by ICP-MS analysis

Forty-seven glass fragments excavated at Veh Ardašīr, in central Iraq, were analysed by ICP-MS, determining 38 chemical elements; the samples represented finished objects as well as waste and raw glass. The obtained data point to the use of sodic plant ash for the production of glass in the entire Sasanian period (third–seventh century AD), strengthening previous results from another set of fragments from the same site. Magnesium and phosphorus contents give further evidence of the possible use of different kinds of plant ash, while trace element levels and some element correlations suggest the recourse to different silica sources. As a whole, the obtained results allow one to recognize three main glass compositions, related to the use of different silica sources combined with different kinds of plant ash. The occurrence of waste and raw glass in all groups of composition confirms that at least glass working took place in Veh Ardašīr.     

Chemical analysis of 17th century Millefiori glasses excavated in the Monastery of Sta. Clara-a-Velha,Portugal: comparison with Venetian and façon-de-Venise production

A set of ten Millefiori glass fragments dating from the 17th century, originated from archaeological excavations carried out at the Monastery of Sta. Clara-a-Velha (Coimbra, Portugal), were characterized by X-ray electron probe microanalysis (EPMA), Raman microscopy and UV–Visible absorption spectroscopy. All glasses are of soda-lime-silica type. The use of coastal plant ash is suggested by the relatively high content of MgO, K₂O and P₂O₅, as well as by the presence of chlorine. Tin oxide or calcium antimonate were the opacifiers used in the opaque glasses, cobalt in the blue glasses, copper in the turquoise glasses, iron in the yellow and greenish glasses, and iron and copper were found in the opaque red and aventurine glasses. Based on the concentrations of alumina and silica four different sources of silica were identified, allowing the classification of the glasses into the following compositional groups: low alumina (<2 wt%), which includes a sub-group of cristallo samples with SiO₂ > 70 wt%, medium alumina (2–3 wt%), high alumina (3–6 wt%) and very high alumina (>6 wt%). Comparison with genuine Venetian and façon-de-Venise compositions showed that two fragments are of Venetian production, one of Venetian or Spanish production and the remaining are of unknown provenance. In two fragments the glass of the decoration is probably Venetian or Spanish but the glass used in the body is also of unknown provenance.     

Silk Road glass in Xinjiang,China: chemical compositional analysis and interpretation using a high-resolution portable XRF spectrometer

In this paper we explore the major, minor and some trace elements of sixty-five glass beads from eighteen oasis sites both north and south of the Taklamakan Desert, the ancient centre of the Silk Routes linking East and West; the samples date from the Warring States period (475–2211 BCE) to the Tang Dynasty (618–907 CE). Using a high-resolution portable XRF spectrometer, with special attention to issues of surface weathering and sample preparation, we obtained quantitative chemical compositional data that, when combined with archaeological context and the technology of bead manufacture, provide the basis for an understanding of both changes in glass type over time, and possible source areas for the Xinjiang glasses. While glass beads at the early sites (1st c. BCE to 4th c. CE) were coming primarily from Kushan-controlled territories in northern India, Pakistan and Afghanistan, with a small contribution from central China, most of the later glass (4th–10th c. CE) is similar to that produced in the Sasanian Empire at such sites as Veh Ardashir in central Iraq. These changes most likely reflect changing cultural and economic conditions in the Silk Road towns.     

Western Mediterranean sand deposits as a raw material for Roman glass production

During the Late Roman and Byzantine period, natron glass was made from its raw materials in a limited number of primary production centres in Egypt and Syro-Palestine. For the earlier Hellenistic and Roman period, no primary furnaces have been found and the location of primary production during this era remains unclear. Ancient authors such as Strabo and Pliny the Elder suggest that glassmaking sands were found near the River Belus (Israel), in Egypt, near the mouth of the Volturno River (Italy) and also in Spain and France. However, primary production in the western part of the Mediterranean is not supported by any direct archaeological evidence and possible sand raw materials from these regions have never been evaluated for their suitability to produce glass.     

Igbo-Ukwu and the Nile

The external connections of Igbo-Ukwu, in the forest belt of south-eastern Nigeria, around the ninth century AD, are demonstrated by the large numbers of glass beads, apparently of Egyptian manufacture, and are implicit in the rich collection of bronze artwork that lacks known prototypes. Although the metals were mined locally, the labor and the expert alloying and casting of numerous ritual or ornamental objects indicate an accumulation of wealth derived from distant trade of special commodities. The identification of these commodities, however, and the routes by which they—and in the reverse direction the beads—would have traveled, remain unsatisfactorily resolved. A preference is repeated here for an eastern Sahelian routing from Lake Chad to the Middle Nile kingdoms (Alwa and Makuria/Dongola), then at their height, thus avoiding the Sahara. The alternative direction suggested recently (Insoll, T., and Shaw, T. (1997) Gao and Igbo-Ukwu: Beads, interregional trade and beyond. African Archaeological Review, 14:9–23), through Gao on the Niger bend and across the west-central Sahara, seems less likely on grounds of geography and chronology. The essential items of merchandise deriving from Igbo-Ukwu are unlikely to be those commonly assumed for sub-Saharan Africa, notably ivory and slaves, but would have been more local and precious, presumably metals. The bronzes stored and buried at Igbo-Ukwu might be regarded as by-products of this export activity. Demands in the Nile Valley for tin (for bronze alloying) and for silver, both of which occur in the ores exploited, deserve consideration. A call is made for comparative study of metals and their uses between the Middle Nile and West Africa in the first millennium AD—a neglected subject owing to the intellectual gulf that persists between Africanists and Egyptologists.Les contacts extérieurs d'Igbo-Ukwu, dans la région forestière du sud-est du Nigéria, vers le 9^e siècle après J. C., sont indiqués par les très nombreuses perles de verre, apparemment de fabrication Égyptienne. Ils sont aussi suggérés par un ensemble remarquable d'objects en bronze dont on ne connaît aucun prototype. Bien que les métaux proviennent de la région, le travail, et aussi l'alliage et la fonte très spécialisés de nombreux objects rituels ou décoratifs, indiquent une accumulation de richesse résultant du commerce à longues distances de produits recherchés. Pourtant, l'identification de ceux-ci, et les itinéraires pour leur transport—et, en sens inverse, ceux des perles—restent hypothétique. Nous réiterons une préférence pour une route est-Sahelien, de Lac Tchad jusqu'aux royaumes du Nil Moyen (Alwa et Makouria/Dongola), à leur apogée à cette époque, et donc évitant le Sahara. L'autre direction, proposée récemment (dans cette revue par Insoll et Shaw), via Gao sur la boucle du Niger et à travers le Sahara ouest-central, semble moins probable pour les raisons géographiques et chronologiques. Les objets principaux de ce commerce qui provenaient d'Igbo-Ukwu ne seraient pas ceux qui sont normalement imaginés pour l'Afrique Sub-saharienne, notamment l'ivoire et les esclaves; ce seraient des produits plus locaux et précieux, vraisemblablement des métaux. Les bronzes enterrés à Igbo-Ukwu pourraient être les sous-produits de cette activité destinée à l'exportation. La demande dans la vallée du Nil pour l'étain (pour l'alliage du bronze) et pour l'argent, qui existent tous les deux dans les minerais du sud-est du Nigéria, mérite considération. Il faut qu'on fasse des recherches comparatives sur les métaux et leurs emplois entre le Nil Moyen et l'Afrique de l'Ouest durant le premier millénaire après J. C.—un sujet négligé à cause du fossé intellectuel qui persiste entre les études Africanistes et Égyptologiques.