ROMAN WINDOW GLASS: A COMPARISON OF FINDINGS FROM THREE DIFFERENT ITALIAN SITES

Thirty‐three samples of window glass and five glass lumps coming from three Italian archaeological sites—the Suasa excavations (Ancona, settled from the third century bc to the fifth to sixth centuries ad ), the Roman town of Mevaniola (Forlì‐Cesena, settled from the Imperial Age up to the fourth century ad ) and Theodoric's Villa of Galeata (Forlì‐Cesena, settled from the sixth century ad onwards)—were analysed to track the changes in the chemical composition and manufacturing technology of window glass through the centuries. The aims of this study were: (1) to establish the origin of the raw materials; (2) to verify the chemical homogeneity among samples coming from different sites and/or produced using different techniques; and (3) to sort the samples into the compositional groups of ancient glass. The analysis of all the chemical variables allowed two groups to be distinguished: (a) finds from Mevaniola and Suasa; and (b) finds from Galeata. All the samples had a silica–soda–lime composition, but the analysis of minor elements—in particular, of Fe, Mn, and Ti—made it possible to split the samples into two groups, with the higher levels of these elements always found in the Galeata samples (HIMT glass). In conclusion, it can be asserted that the main differences between the samples are related to their chronology.     

LUSTRE COLOUR AND SHINE FROM THE OLLERIES XIQUES WORKSHOP IN PATERNA (SPAIN), 13TH CENTURY AD: NANOSTRUCTURE,CHEMICAL COMPOSITION AND ANNEALING CONDITIONS*

Lustre is a medieval ceramic decoration, corresponding to a nanostructured thin layer formed by metallic copper and silver nanocrystals embedded in a glass matrix, which required deep knowledge on the part of the artisans with regard to the raw materials used and the kiln conditions. Their empirical knowledge led to the achievement of colourful lustre decorations ranging from reddish to yellowish or even greenish, some of them with a metallic shine with an associated purplish iridescence. Lustre ceramics dating from the 13th century from the Olleries Xiques workshop in Paterna (Spain) have been studied, linking their chemical composition and nanostructure with their colours and shine. Two kinds of nanostructures are found, yellowish lustre decoration constituted by a silver metal–glass nanocomposite, and reddish lustre decoration constituted by metallic copper nanocrystals and copper oxide nanocrystals; in some cases, metallic copper nanocrystals covered with an oxidized shell of CuO and partly Cu₂O have been found. However, even with significant amounts of copper oxide, the lustre still exhibits a copper metal‐like shine. The bluish iridescence observed at a specular angle in the lustre could not be explained completely by means of the chemical composition, and metallic silver nanoparticle light scattering is proposed as a possible explanation.     

A NEW SETTING FOR THE NORTHERN BORDER OF THE VENETI: METALLIC FINDS FROM THE VENETIC SITE OF MONTE CALVARIO,AURONZO DI CADORE*

In 2000 several bronze and lead objects were discovered at the Venetic‐Roman site (200 bc –ad 200) of Monte Calvario di Auronzo, in the Italian eastern Alps. They were mostly finished artefacts plus semi‐worked products. Analysis included SEM–EDS, EMPA, XRPD, TMS and AMS spectrometry. The compositional results of the finished artefacts suggest that the choice of the alloy had been made according to the decorative techniques to be used. A semi‐worked high‐leaded bronze object indicates the existence of a metallurgical production of cast artefacts at the site. TMS analyses of a lead ingot exclude local provenance, proving the existence of important trade routes.     

徐州狮子山楚王陵出土金缕玉衣和镶玉漆棺的 玉料组分特征及产地来源研究

为了解西汉玉器的组分特征及玉料来源,利用显微放大观察结合电子探针、红外光谱、拉曼光谱和LA-ICP-MS技术,对徐州狮子山西汉楚王陵出土的部分玉片(玉衣片和玉棺片)样品进行了检测分析。检测结果表明:1)显微放大观察发现:出土玉片样品均含石墨包裹体,不可能来自不含石墨包裹体的福建南平闪石玉和江苏溧阳小梅岭闪石玉。2)电子探针结果显示:出土玉片样品为透闪石;出土玉片样品的ω(FeO)/%范围为0.287～0.925,不可能来自富Fe的玛纳斯闪石玉及贫Fe的的青海闪石玉;ω(Al_2O_3)/%远远高于河南栾川软玉。3)红外光谱分析显示:出土玉片样品为透闪石,与电子探针结果相符;玉片样品的M-OH伸缩振动谱带位置集中在3674cm~(-1)附近,说明玉料Mg含量较高。4)拉曼光谱分析显示:出土玉片样品具有和透闪石矿物共同的特征拉曼谱峰,为透闪石质软玉,与电子探针及红外光谱结果相符。5)LA-ICP-MS分析显示:出土玉衣片样品的稀土元素质量分数及分馏情况与辽宁岫岩闪石玉、四川汶川龙溪闪石玉及河南栾川闪石玉有所不同;Cr、Ni、Co含量较低,指示玉料来自热液交代型镁质大理岩型软玉矿床;Sr含量较低,排除了来自江苏溧阳小梅岭闪石玉的可能。分析结果表明,徐州狮子山楚王陵出土玉器玉料来源主要和新疆和田地区玉料有关;新疆和田地区的闪石玉至西汉早期已覆盖到楚文化区域,并且成为宫廷玉料的主流来源。     

ARCHAEOMETRICAL INVESTIGATION OF SICILIAN EARLY BYZANTINE GLASS: CHEMICAL AND SPECTROSCOPIC DATA*

A series of early Byzantine glasses, recovered in Ganzirri (Sicily, Italy), was analysed for major, minor and trace elements. All the analysed fragments were found to be natron-based silica–lime glass. Concerning minor and trace elements, the samples can be divided into two groups: glass with high Fe, Ti and Mn contents ( HIMT glass) and glass with low levels of Fe, Ti and Mn. These results, strictly in agreement with literature data for glass of the Mediterranean region, can be interpreted as a consequence of the wide trade network established in this region and of the intense circulation of raw glass and artefacts from different Mediterranean areas. X-ray absorption spectroscopy studies at Fe and Mn K-edges, performed on HIMT glass, indicate that Fe is in the oxidized form while Mn is in the reduced form.     

The Mediterranean Group II: analyses of vessels from Etruscan contexts in northern Italy

A large number of Mediterranean Group vessels were recovered at the Etruscan site of Spina in northern Italy and dated from the 6th to the 3rd century BC. In this work a number of vessels belonging to the so-called “Group II” were analysed. The samples are mainly Alabastra, Oinochoai, Amphoriskoi, and Hydriai, in general opaque and deeply coloured. The aims of this study are: 1) to characterize these samples since there is a lack of data in literature regarding Mediterranean Group II; and 2) to compare the data obtained with that of glass for previous centuries (Mediterranean Group I) recovered at the same site in order to establish whether they could have the same origin. The chemical analyses of major and minor elements were carried out by electron microprobe and the nature of the opacifying and colouring agents was determined by X-ray diffraction. The sample set is relatively homogeneous and most of the samples can be classified as Low Magnesium Glass produced with natron and a calcareous silicatic sand. The XRD analyses proved the use of lead antimonates in the manufacture of yellow decorations and of calcium antimonates in the white and light blue decorations. The consistency of the chemical compositions of Mediterranean Groups I and II samples makes it possible to hypothesize a common origin.     

MOSAIC GLASS FROM ST PETER'S,ROME: MANUFACTURING TECHNIQUES AND RAW MATERIALS EMPLOYED IN LATE 16TH‐CENTURY ITALIAN OPAQUE GLASS

A recent restoration of late 16th‐century mosaics in one of the vaults beneath the dome of St Peter's Basilica in Rome allowed sampling and analysis of a group of glass tesserae. The aim of this work is the characterization of opaque coloured glasses possibly produced in Rome. The characteristics of the glass from St Peter's were compared with those of Venetian and Tuscan production, in order to assess possible common origins. Chemical analysis of 30 samples was carried out by electron microprobe, while the nature and morphology of opacifiers were determined by X‐ray diffraction and scanning electron microscopy. Almost all the opaque samples were characterized by the presence of SnO₂ crystals. In addition, depending on the colour of the glass, other crystalline phases were identified: lead‐tin oxide (PbSnO₃) in yellow glass, cuprite (Cu₂O) in orange glass and two calcium‐tin silicates with different stoichiometry (CaSnSiO₅ and Ca₃SnSi₂O₉) in the green‐yellow variety. A frame of reference for identifying raw materials and glass‐making techniques is provided by textual sources, here examined in comparison with the compositional characteristics of the tesserae from St Peter's.     

Late antique glass from Salapia: Tracking production and trading networks

The investigation of 38 late antique vessels from the archaeological excavation of Salapia has been performed using EMPA and LA-ICP-MS. The collection was made using impure sands and mineral soda. Among coloured glass, most vessels were made of ‘fresh’ glass. The use of colouring agents is rare, and most decoloured glass is obtained by Mn addition. Sb-decolouration is limited to one cup, and two colourless vessels show both manganese and antimony. As for provenance, the prevalence of Egyptian-HIMT glass over the Levantine is evident. Among Levantine glass, Jalame glass is represented, whereas Apollonia glass is absent. Among Egyptian (and deemed Egyptian) glass, the prevalence of HIMT glass over the other types has been observed. The high attestation of fresh glass, most notable in the earlier centuries, suggests the importation of glass in the form of finished objects, especially luxury vessels.     

Application of electron microprobe analysis to identify the origin of ancient pottery production from the Castillo de Huarmey,Peru

A vast amount of ceramics (among other grave goods) were recovered from Castillo de Huarmey, a Wari culture (650–1050 ce ) archaeological site on the north coast of Peru. In order to assess ceramic production area(s) and possible trade, political or cultural interactions with other regions, and to complement earlier petrographic analysis, electron microprobe analysis (EMPA) was conducted following a rarely used methodology in archaeology. The chemical composition of individual minerals in ceramics and sediments samples from the Huarmey Valley was obtained, focusing mainly on amphiboles, feldspars and pyroxenes. The results of the analyses clearly indicate that the majority of the ceramic analysed was made of raw material of local origin.     

The first archaeometric data on polychrome Iron Age glass from sites located in northern Italy

A large sample set of transparent and opaque glass artefacts recovered from Etruscan contexts in northern Italy (Bologna and Spina (FE) necropoleis) and dated to a period between the 6th and 4th century BC are analysed in this paper. Samples of highly decorated beads, spindle whorls and vessels of the ‘Mediterranean Group I’ (Alabastron, Oinochoes, Amphoriskos) were selected in order to determine whether these different glass artefacts were produced at the same manufacturing site. While the vessels almost certainly originate from Greece, the beads could derive from a more ancient local production ascertained at the site of Frattesina (Rovigo, Italy) and dated to the Bronze Age.