Chemical composition and colouring agents of Roman mosaic and millefiori glass, studied by electron microprobe analysis and Raman microspectroscopy

About 100 fragments of Roman mosaic and millefiori glass were stylistically attributed to a Hellenistic type, a Ptolemaic and Romano-Egyptian period type and an early imperial period type. Twelve representative fragments were studied by electron microprobe analysis and Raman microspectroscopy. Eleven of them display a Na-pronounced recipe with low K, Mg and P contents, typical for the Roman period. Minor differences in composition are unsystematic, not reflecting the stylistic classification. Ionic colouring agents are Mn³⁺ for violet, Cu²⁺ for light blue, Co²⁺ for deep blue and Fe³⁺ for brown translucent colours. Calcium antimonates, lead antimonate and cuprite are the colourants responsible for white, yellow and red colours, respectively, and additionally serve as opacifiers. Mixing of ionic colouring agents and opacifying colourants led to a more differentiated palette of colours. Pb was used as yellow colouring agent, as a flux material and as a stabiliser for the colourant crystals. The remaining fragment consisting of a K-pronounced but still Na-bearing glass matrix was most likely produced during the Middle Ages or later.     

中国出土的一批战国古玻璃样品化学成分的检测

对化学成分体系的确定是中国古代玻璃研究中很重要的一个方面,为此,用外束质子激发X荧光技术(PIXE)、电感耦合等离子体原子发射光谱分析(ICP AES)等方法,对新疆、湖北、河南和重庆等地区出土的一批战国时期的玻璃珠(包含镶嵌玻璃珠)、玻璃璧样品进行了检测。结果表明,战国时期中国境内同时存在PbO BaOSiO2、K2O SiO2、Na2O CaO SiO2三种硅酸盐玻璃,分布的地域范围从中国的新疆东部一直到长江、黄河流域,以及南方的四川、贵州等地区。中国古代的PbO BaO SiO2和K2O SiO2玻璃在技术发展上应该具有密切联系。结合文献资料对这些玻璃的产地等相关问题进行了简要讨论。     

基于多元统计分析方法对一批中国南方和西南地区的古玻璃成分的研究

采用多元统计方法对四川、重庆、贵州、广西、广东地区出土的100余个古玻璃样品的化学成分数据进行了分析处理。结果表明:中国南方和西南地区的古玻璃制品主要由具有中国特色的铅钡硅酸盐玻璃和钾硅酸盐玻璃组成,可细分为五大系统类别:K2O CaO(~10wt%)SiO2系统、K2O SiO2系统、PbO BaO SiO2系统、PbO(~25wt%)BaO SiO2系统、CaO PbO(~40wt%)BaO SiO2系统。用因子分析探讨了我国汉代南方和西南地区的玻璃本地生产情况,表明该地区在汉代已经拥有自主生产古玻璃的能力。实验结果和实验数据处理方法对研究古代丝绸之路上古玻璃的生产和技术交流提供了新途径。     

化学组成分析辅助判别古陶瓷产地、制作年代及工艺的研究

化学组成分析是古陶瓷科学研究的基础.本文对目前化学组成分析在辅助判别古陶瓷产地、制作年代及工艺中的应用成果作了归纳总结.同时,结合自身研究,举例说明元素化学组成在判别古陶瓷产地、制作年代等一些成功的模式.     

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.     

Chemical characterization of ancient pottery from sudan by x‐ray fluorescence spectrometry (xrf), electron microprobe analyses (empa) and inductively coupled plasma mass spectrometry (ICP–MS)*

Sixty‐four sherds and seven natural clays from prehistoric sites in northwestern Sudan have been submitted to petrological and chemical analysis using XRF spectrometry, EMPA and ICP–MS. According to their texture, the sherds form five different groups. The high contents of P₂O₅ (more than 0.5 wt%) discerned in 19 samples and the variation of the P₂O₅ content in two samples of the same vessel can be explained by post‐depositional processes or by the ancient organic contents (e.g., milk) of the vessel. Chemical classification of the pottery bulk suggests that vessels were made locally, as only sherds from the same area show homogeneity of data.     

Neutron activation analysis of some roman and islamic coarse wares of western cyrenaica and crete

Coarse wares from western Cyrenaica and southern Crete are similar in shape and workmanship and are not distinguished petrologically. It has been possible to identify three distinct groups by neutron activation analysis: (1) Keratokambos (Crete); (ii) Benghazi lime-rich ware; (iii) Benghazi shell-rich ware. The element ratios for (ii) and (iii) are 1·52 ± 0·16 (excluding Na) which suggests a dilution of clay from the same source by shell for example in the shell-rich ware.The element ratio for Na is only 1·01 and the Na concentration increases linearly with time. This could be Na absorption with time from the brackish water for which the region is renowned.     

古陶瓷的成分测定,数据处理和考古解释

化学组成测定是古陶瓷科学研究的基础。作根据亲身实践,对几种常用的,或有发展前景的陶瓷化学组成的测量方法作了综评,定量地估计了它们的灵敏度,精密度和准确度。本还对古陶瓷化学组成数据多元统计处理中变量和样品的选择和舍弃,数据处理结果的表述,特别是作考古推论中的某些问题进行了探讨。     

Characterization of some ancient glass beads unearthed from the Kizil reservoir and Wanquan cemeteries in Xinjiang,China

A total of 33 ancient glass beads unearthed from the Kizil reservoir cemetery and Wanquan cemetery in Xinjiang are studied using Raman spectroscopy, scanning electron microscopy with energy‐dispersive spectrometry (SEM–EDS) and other methods. The detailed study of the glassy matrices, the crystalline inclusions and the microstructural heterogeneities for these glass beads has revealed some valuable information to help in the understanding of their possible manufacturing technology and provenance. At least two different types of glass were present in the two cemeteries. For the first time, antimony‐based colourant/opacifier—for example, Pb₂Sb₂O₇ or CaSb₂O₆—was systematically identified in some beads of plant‐ash type soda–lime glass dated to about 1000–500 bc . The limited number of potash glass beads from the Kizil reservoir cemetery, which were dated to about 500–300 bc , used tin oxide as an opacifier. The diverse resources of the soda–lime and potash glasses indicate the existence of a complex trade network between China and the West much earlier than the Western Han Dynasty.     

The crystallinity of ancient bone and dentine: new insights by transmission electron microscopy

We studied various archaeological and palaeontological bones and dentines from different burial environments by Fourier transform infrared spectroscopy (FT–IR), X–ray diffraction (XRD) and transmission electron microscopy (TEM), in the framework of a general study of diagenesis. FT–IR and XRD were used to evaluate the global preservation state of the bone and dentine mineral phase by determining a splitting factor (SF) or a crystallinity index (CI), respectively. These data can be combined with studies on the nanometer scale made with TEM. This latter technique,coupled with electron microdiffraction, provides determination of dimensions and shapes of individual bone and dentine apatite nanocrystals as well as of secondary minerals formed during diagenesis. It enables us to distinguish between heat–induced recrystallization processes and crystal growth in solution occurring during diagenesis.     

Glass on the Amber Road: the chemical composition of glass beads from the Bronze Age in Poland

The article discusses the chemical composition of 56 glass samples from 52 beads found in Poland at 13 archaeological sites (mainly cemeteries). The artefacts have been dated to the II–V period of the Bronze Age (=phases BzB–HaB; c. 1600–750/700 bc). The LA-ICP-MS method was applied. Two groups were distinguished in this assemblage based on a comparison of the MgO to K₂O ratio in glass: (i) high magnesium glass (HMG)—23; and (ii) low magnesium and high potassium glass (LMHK)—33 (29 matrix glass specimens and 4 decorative). In southern Poland, beads made of HMG and LMHK are often found in the same cemeteries. Analyses have shown that HMG was most probably made in Mesopotamia and that at least one cobalt glass is of Egyptian provenance. LMHK glass was made in Europe, most probably in Italy. Also, Italy was the most probable transit point for artefacts made of HMG en route to East-Central Europe.     

从“鸭形玻璃注”看北燕时期中西交流

魏晋南北朝时期,中原动荡,中西商路受阻,而北方草原的特殊地利却为中西交流搭建了平台,不断增多的考古发现说明了草原丝绸之路上的双向交流情况。北燕冯素弗墓出土了“鸭形玻璃注”等一批精美的玻璃器皿,应是十六国时期由草原丝路从罗马传入的舶来品,见证了北燕时期的中西交流。     

Florence baptistery: chemical and mineralogical investigation of glass mosaic tesserae

A recent restoration of the mosaics of the Baptistery in Florence enabled the collection and analysis of a group of glass tesserae. Twenty-three tesserae, dated between the end of the 13th century and the first half of the 14th century, showing different colors were sampled and analyzed to identify the raw materials, colorants and opacifiers employed in their production.     

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.     

An early Iron Age assemblage of faience beads from Ashkelon,Israel: chemical composition and manufacturing process

The microstructure and chemical composition of eight faience beads from an early Iron Age (12th century BCE) assemblage found in the ancient city port of Ashkelon (Israel) are determined by means of FTIR spectrometry, pXRF, microRaman and SEM-EDS analysis. The results are compared with published data of Egyptian and Near Eastern artifacts. Each sample exhibits a hue which is obtained by adding a specific colorant to the glazing mixture. A new gray chalcopyrite-manganese-based colorant was identified. Cementation glazing was most likely used in the manufacturing process of the specimens analyzed, except for the blue bead, which is an Egyptian blue frit. The results suggest that these objects represent a unique assemblage, quite different from contemporary Egyptian and Near Eastern materials, and provide new information regarding the Iron Age faience evidence in the southern Levant.     

Change in chemical composition of early Islamic glass excavated in Raya,Sinai Peninsula,Egypt: on-site analyses using a portable X-ray fluorescence spectrometer

The Raya port (eighth to 12th centuries) on the Sinai Peninsula, Egypt, was one of the important port cities for the Red Sea trade. We performed on-site analyses of Islamic glass vessels (used in eighth to 11th centuries) mainly from this site in Egypt using a portable XRF spectrometer. The aim of this paper is to contribute to our understanding of the chemical compositions of early Islamic glass vessels by comparing their archaeological date and typology. In the early Islamic period, glass objects were mainly produced from natron as the soda source. Among the natron glass analyzed in this study, glass vessels with low titanium and iron and high strontium contents, which were probably produced in the Syria–Palestine region, were excavated in the eighth century layer. From the ninth century layer, a large number of samples with high levels of calcium, titanium and iron, probably produced in Egypt, were found. It should be noted that a large number of glass vessels with this chemical composition were found at the Raya site, because this type of glass was rarely reported from other Islamic sites. We finally concluded that this type of glass seems to be produced under a fixed recipe, although some samples contain a colorant or decolorized materials.     

The solar eclipse of 26 February 1979: analysis and modelling of primary pair production,electron density and ionic composition

The solar eclipse of 26 February 1979 was observed from Red Lake, Canada, (52 °N, 91 °W) where totality occurred at about 1053 local time. Several research groups and government agencies participated in an extensive ground- and rocket-based observational program directed at the middle atmosphere. At the time of the eclipse, an extensive geomagnetic storm was in progress and the middle atmosphere was undergoing temperature and circulation changes associated with a stratospheric warming. Concurrent observations of atmospheric constituents, solar radiation, electron flux and other middle atmosphere parameters were obtained as inputs for a D-region predictive chemical computer code, DAIRCHEM, tailored to eclipse conditions. Ion pair production rates were computed by an E-region infrared radiance model and were used as necessary source function input values for DAIRCHEM computations. The computations yielded predictions of electron and total positive ion densities about totality. The positive ion measurements of a supersonic Gerdien condenser and a subsonic blunt probe during the eclipse were in agreement with the model computations and provided normalizing summations of total positive ions for the interpretation of mass spectrometer measurements. The chemical computer code identified principal routes for increase and removal of key species such as O₂⁺, NO⁺, hydrated clusters and negative ions. The dominant precursor ion for pair production hydrates was O₂⁺ and the chemistry was characteristic of the disturbed D-region.     

Provenance of glass shards in archaeological lime plasters by LA-ICP-MS: implications for the ancient routes from the Gulf of Mexico to Teotihuacan in Central Mexico

We present the chemical characteristics of samples collected from the central courtyard of Teopancazco, a neighbourhood centre in Teotihuacan (Mexico), the most important classic Mesoamerican city. The rhyolitic glass shards used as aggregates have a composition comparable to the glass material sourced from the magmatic system of Altotonga (located along the route to the Gulf Coast). People travelling from the Gulf Coast may have transported the glass shards to Teotihuacan during the Xolalpan phase (350–550 AD). However, the reasons for using glass shards as a construction material remain unknown. These new data confirm the close relationship between inhabitants of Teopancazco and the Gulf Coast already revealed by previous archaeological and archaeometric studies.     

The early roman imperial AES coinage II: Tracing the copper sources by analysis of lead and copper isotopes—copper coins of Augustus and Tiberius*

Lead and copper isotopes of Roman Imperial copper coins (denominations as and quadrans) were analysed by MC–ICP–MS. We concentrated on well‐dated coins minted at the official mint of Rome under the Emperors Augustus and Tiberius (between 16 bc and ad 37). The lead isotope results were compared with published lead isotope data of ore bodies from the Aegaean, Cyprus, Italy and Spain, in order to fingerprint the sources of Roman copper. During the Augustan period the main copper supply, as judged from the copper coins, is from Sardinia and south‐east Spain, with minor contributions from Tuscany. Except for Tuscany, this continued into the Tiberian period, when Cypriot copper also appears. Augustan quadrantes and late Tiberian asses came solely from the Rio Tinto area in south‐west Spain. Copper isotopes were applied here for the first time to systematic archaeometric studies. They are supplementary to lead isotopes and allow further grouping and classification of the copper coins.