昆明羊甫头墓地出土青铜器的分析研究

为了对羊甫头出土青铜器的保存状况、锈蚀结构有全面的了解,同时对出土青铜器的原料配比、冶金技术、制作工艺进行研究。从不同的器物及残片上采集了32个青铜样品,应用扫描电镜、面探测器X射线衍射仪等方法对样品进行了合金成分分析及锈蚀产物检测。分析结果表明,羊甫头墓地青铜器物是用多种金属制作而成,器物主要是Cu-Sn合金,其次是红铜、Cu-Sn-Pb、Cu-Pb-Sb等合金;锈蚀产物主要以孔雀石、锡石、石英、赤铜矿等为主。     

Uses of Gold in Jewellery

Abstract

Gold plays a dominant role in the jewellery market. This is to a large extent due to the intrinsic value of gold, its beauty and its unique resistance to tarnish and corrosion. In 1990 the amount of gold used in jewellery was about 2000 t worldwide, reaching about 75% of the total demand for gold. The demands on gold materials for jewellery, its applications in the form of bulk material for wrought and cast jewellery and as gold solutions for electrodeposition and electroforming as well as activities to introduce powder materials for the manufacture of jewellery are described. Today's conventional carat gold alloys are reviewed; coloured gold alloys based on the Au–Ag–Cu system, as well as the white gold alloys, based on Au–Ni or Au–Pd alloys. Additionally, the development of special gold alloys is mentioned, for instance that of a very high carat gold alloy, 990 gold–titanium.     

Manganese Black Pigments in Prehistoric Paintings: the Case of the Black Frieze of Pech Merle (France)

Different black pigments of natural origin (mineral or organic) have been examined by means of several analytical methods (colour measurements, elemental analysis and structural analysis). The results, after being compared with each other, then served as reference points in the study of the ‘Black Frieze’ of the cave of Pech Merle (Lot). After that, colour measurement was investigated in situ on the paintings as a means of displaying small differences (in hue or chroma) between the black colours. The aim of this study was to verify several hypotheses concerning the techniques used by the painters of Pech Merle, and specifically by the one(s) of the Black Frieze. A first objective was that of identifying the nature and, if possible, the origin of the black pigments used in these figures. A second objective was that of determining in which parts of the frieze one or the other (or one and the other) had been used; and the final objective was to provide new technical information that might help us better to understand how the Pech Merle frieze was produced, whether by a single painter and in one episode, for the most part, or, on the contrary, in several episodes and by a succession of different painters.     

COMPOSITION PROFILES AND TIME EVOLUTION OF BURIED MARBLE PATINAS BY LA–ICP–MS AND LASER‐INDUCED MICRO‐PHOTO‐LUMINESCENCE

The present work aims to study surface composition profiles on buried marbles as well as their time evolution. Fifty samples from gravestones, buried for up to 80 years, were analysed by laser‐induced photoluminescence and LA–ICP–MS. The results include profiles of ²⁵Mg, ²⁷Al, ⁵⁵Mn, ⁵⁷Fe, ⁸⁸Sr and organic complexes of calcium, existing in the marble patina. The depth at which ⁸⁸Sr reaches its bulk value proved to be the best parameter to measure patina thickness. A diffusion model adopted from dissolution studies made on gravestones exposed to the atmosphere was successfully applied to the patina thickness data. The model fails to predict patina thicknesses for ancient excavated objects. However, it seems that ‘Sr alteration depth’ values alone can be used for discriminating ancient from recently buried surfaces.     

Touchstones: some aspects of their nomenclature,petrography and provenance

Touchstones are pieces of fine-grained black stone which are used for assaying gold by comparing the colour of streaks made on the surface by alloys of known composition with the colour of the streak from an object of unknown composition. The technique has been in use since at least the 6th century BC.The petrographic aspects of the identification of touchstones are reviewed and 42 historical touchstones or museum specimens of similar looking stone are described, most of them including the results of petrographic examination.The results show that touchstones usually consist of sedimentary rock types, of which the most frequently occurring ones are tuffs, cherts and siltstones.     

新干商代大墓青铜器腐蚀分析研究

为进一步了解新干商代大墓青铜器的腐蚀机理,用扫描电子显微镜、面探测器X衍射仪、离子色谱等仪器,对这批青铜器的腐蚀现象分三个方面进行了锈蚀结构、青铜基体、微观形貌观察的研究。研究结果表明,三种不同类型的腐蚀结构表面锈蚀成分主要是SnO2,样品表面锡含量均高于基体。漆古表面有龟裂纹,氧、锡元素分布从外至内层递减;铜元素从外至内递增。青铜器上残留土样中未检测出侵蚀性氯离子。实验结果可为保护这批青铜器提供科学依据。     

Mary McLeod Bethune's Feminism: Black Women as Citizens of the World

This article focuses on the particular moment of the 1945 United Nations charter meeting as a catalyst for a shift in Mary McLeod Bethune's feminist thought. The meeting, where Bethune served as the only African American female delegate, signalled a change in Bethune's thinking about equality for black women, so she used the founding of the United Nations as a platform to promote black women's alliances with other women of colour. Her idea was to reframe black women as citizens of the world, thus putting them in a numerical and ideological majority rather than keeping them in a minority position. Bethune has often been viewed as a reformer of race and gender issues in the early twentieth century, but a focus on her activism has hidden the intellectual contributions that she made to a form of black feminism that emerged out of her work with other clubwomen and through the United Nations in the 1920s through the 1950s. Specifically, this article argues that Bethune's intellectual work created a framework for African American women's feminism that emphasised anti-colonialism and their global alliance with other women of colour throughout the world.     

Black Gloss Pottery: Production Sites and Technology in Northern Etruria,Part II: Gloss Technology

The present study aims to understand the reasons for the visual differences of black gloss pottery found in northern Etruria. The results obtained by conventional (scanning electron microscope, electron microprobe) and synchrotron (X‐ray diffraction, X‐ray absorption spectroscopy) techniques indicate that the thickness, porosity or chemical composition of the different types of gloss cannot be used as the principal distinguishing factor. The size of quartz or feldspar crystals may well be a critical factor responsible for the matt effect in some samples, while the range of mixtures of iron compounds indicated by XRD and XAS could be the reason for differences in colour and reflectivity. The Fe L‐edge XAS results in particular show that a correlation does exist between the oxidation state characteristics and the visual appearance. The Si, Fe and Al contents seem to further discriminate the different types of gloss that have differing visual appearances.     

QUANTITATIVE ANALYSIS OF COPPER-TIN BRONZES BY MEANS OF GLOW DISCHARGE OPTICAL EMISSION SPECTROMETRY

Glow discharge optical emission spectrometry (GDOES) has been used for obtaining calibration curves for copper, tin, lead, silver, antimony, arsenic, zinc and iron from standards including copper-base alloys (Cu 61.33-99.95%) and from bronze Punic coins. The GDOES results were calibrated using atomic absorption spectroscopy with inductively coupled plasma atomization (ICPAAS) to analyse the standards and coins. For all these materials, the results show that via GDOES it is possible to obtain reliable and reproducible calibration curves for copper, tin, lead, zinc and iron with a linear behaviour as a function of the content. The quantitative GDOES and ICPAAS data for the coins have been also compared with those obtained via X-ray fluorescence (XRF) and it is shown that GDOES, ICPAAS and XRF agree well with one another considering that the bronze coins are inhomogeneous to some degree. As an example of GDOES analytical features, a depth concentration profile through a thin bronze patina is shown and briefly discussed.     

The application of biometry and LA-ICP-MS to provenance isolated bones: a study of hominin remains from Oumm Qatafa Cave,Judean Desert

Three hominin phalanges were recently identified in old faunal collections attributed to the Late Acheulean (Layer D2) dated to ca. 213 Kya, from Oumm Qatafa Cave (Judean Desert), a site excavated in 1928–1949. In terms of general appearance (colour, patina and adhering sediment), these specimens resembled the fauna with which they were found, but the likelihood of stratigraphic problems especially in old excavations, the presence of 4th millennium b.c. burials in the topmost Layer A at the site and the absence of any mention of Late Acheulean hominin remains in publications relating to the site prompted us to verify that the phalanges were indeed in situ. Osteometric examination showed the phalanges to be indistinguishable from those of Middle Paleolithic Levantine anatomically modern humans (AMHS) as well as Upper Paleolithic and recent populations, thus contributing little to the resolution of their provenance. To further investigate this issue, we compared the elemental composition of the phalanges to that of fauna from the same and overlying archaeological layers using non-destructive laser ablation–inductively coupled plasma mass spectrometry (LA-ICP-MS). The results showed a close resemblance in elemental composition between the phalanges and fauna from Layer D2, implying that they are in situ. This would indicate either an early occurrence of AMHS in the region or the presence of an ancestral archaic Homo. We propose that LA-ICP-MS offers a useful minimally invasive method for provenancing isolated human and faunal remains.     

A Study of Biodeterioration and Chromatic Alterations of Painted and Gilded Mummy Cartonnage at the Saqqara Museum Storeroom,Egypt

Microbial biofilms have developed on the surfaces and within the painted and gilded layers of mummy cartonnage at the Saqqara museum storeroom in Giza, Egypt. SEM–EDX, XRD and FT–IR–ATR techniques were applied to analyse the coloured and gilded materials, ground layer, textile support and binder used for the cartonnage. Aspergillus niger (24.8%), Penicillium chrysogenum (21.5%) and a novel cartonnage‐biodegrading bacterium, Bacillus sonorensis (23.7%), were the most abundant microbes growing over the cartonnage surface. In addition, Aspergillus tamari (15.4%), A. fumigates (8.1%) and Fusarium solani (6.5%) were identified. The pigments comprised Egyptian blue (cuprorivaite), cinnabar (red), orpiment (yellow) and green pigment made from a mixture of cuprorivaite and orpiment. Gold leaf was used for the gilded layer, calcium carbonate and gypsum comprised the ground layer, gum arabic was the binding medium and the fibre base was a fine linen textile. Microbial colonization tests were performed on aged cartonnage replica samples made from linen and pigments of similar composition to ancient pigments found in the cartonnage. Each sample was inoculated separately with A. niger, P. chrysogenum and B. sonorensis. Yellow orpiment samples were the exception, as no colour change was detected after colonization by the examined micro‐organisms.     

A Second Investigation into the Chemical Composition of the Roman Provincial (Procuratorial) Coinage of Judaea,AD 6–66*

An investigation of the chemical composition of the first Roman provincial coinage of Judaea, minted in ad 6–66, was conducted. A total of 103 copper‐alloy coins were analysed by ICP‐AES. It was determined that different copper alloys were used for the coinage, a leaded tin‐bronze and a pure tin‐bronze alloy. The investigation also showed that the copper alloy was made in four different formulae with regard to the alloying elements added to copper. Trace element profiles point to the existence of a shared pool of metal for Roman coins and metalwork.     

ANCIENT EGYPTIAN BLACK‐PATINATED COPPER ALLOYS*

This analytical study aims to investigate ancient Egyptian black‐patinated copper alloys. The study group was selected from the collections of the Egyptian Museum in Cairo and from the Faculty of Archaeology Museum in Cairo University. Examination and analysis were undertaken using optical microscopy (OM), scanning electron microscopy (SEM), energy‐dispersive spectroscopy (EDX), X‐ray diffractometry (XRD), X‐ray fluorescence analysis (XRF) and Fourier transform infrared spectroscopy (FTIR). The analysis results indicated that the black patina contained mainly tenorite (CuO). The study presents evidence of thermal patination and animal glue coating.     

Late horizon silver,copper, and tin from Machu Picchu,Peru

Analyses of silver–copper alloy artifacts from Machu Picchu show silver contents ranging from 24 to 81%. The tin present, ranging up to 3%, originated with the copper, perhaps from admixture of recycled bronze. The presence of 0.4–0.9% lead in the silver-rich phase indicates use of silver prepared by cupellation. All the objects had been forged after casting, some extensively. All have surface enhancement of the silver arising from depletion of the copper-rich phase. Some of the tin found at the site contains inclusions of hardhead (FeSn₂) and of a nickel–arsenic–copper compound. Forming trials with duplicate silver–copper alloys show that intermediate anneals at temperatures between 500 and 600 °C facilitate making thin sheet artifacts. Mechanical tests show that the most commonly used alloys, containing 25–30% silver, are particularly well adapted to forging because of their uniform work hardening during plastic deformation. Annealing of the laboratory-made alloys in air followed by boiling in salty weak acid creates a silver-rich surface layer comparable to that found in the artifacts. Depletion forms a dense silver surface on the alloy containing more silver than the eutectic composition, but a porous surface layer on the 25% silver alloys.     

X-RAY FLUORESCENCE ANALYSIS OF ENGLISH 13th-16th CENTURY PEWTER FLATWARE

Most of the thirty-six pewter items were found to have been made from high quality tin-rich alloys with low lead content, hardened with a small amount (0.5–3.0%) of copper; these were thought to be from the later part of the period. Three items, one with the highest copper content of all the alloys, were thought to be from the earlier part of the period. Five items with up to 2% of copper hardener but with lead levels up to 26.5% were thought to be of provincial origin. A possible correlation of alloy composition and date and place of manufacture with rim-form is discussed. A wavelength-dispersive technique was used for the analyses.     

SEM and electrochemical characterization of bronze artifacts from the Francavilla archaeological site

The excavations in the necropolis of the Francavilla Marittima archaeological area, in Calabria, have brought to light the rich burial artifacts and materials, dated between the end of the ninth and sixth centuries BCE. SEM/EDS analysis was conducted on some sections taken from a bronze artifact classifiable as an armilla or fibula fragment. Our aim was to elucidate the nature of the corrosion processes acting on the specimen. SEM investigation detected the segregation of tin towards the outer layer and a depletion of the copper content in the same region. Furthermore, the elemental distribution maps of the sections analyzed evidenced the presence of chloride ions in the border area between the corrosion patina and the metal alloy. Such anion migration of chloride ions into the interior of the alloy leads to a particular variant of the type of corrosion of structure that in the literature has been identified as structure I.A cavity electrode designed for electrochemical measurements of powders was used to perform cyclic voltammetry experiments devoted to explore the activity of the patina covering the surface of the bronze fragment. The surface layer consists mainly of tin and tin oxides; the layer immediately beneath it contains copper oxides. An increase of reactivity was shown in an acidic environment. The activity of the patina is greatly reduced at pH 5 and appears to be zero at neutral pH.     

A STUDY ON LATE MEDIEVAL TRANSPARENT‐GLAZED POTTERY AND ARCHAIC MAJOLICA FROM ORVIETO (CENTRAL ITALY)*

Nineteen samples of medieval transparent‐glazed pottery and archaic majolica from Orvieto (central Italy) were studied. They were classified by archaeological criterion as follows: five transparent‐glazed fragments with green and brown decorations (first half of the 13th century), eight green transparent‐glazed fragments (13th century) and six tin‐glazed fragments with green and brown decorations (second half of the 13th century). SEM–EDX, XRD (the Rietveld method) and XRF were used to characterize the chemical and mineralogical compositions both of the bodies and the coatings. In all of the samples, the paste is Ca‐rich with CaO contents as high as 13–20 wt%. The mineralogical composition is compatible with a firing temperature of about 950°C, which is the typical temperature reached in a wood kiln. No difference was observed between the bodies of transparent‐ and tin‐glazed pottery. In the case of transparent glazes, the burial conditions lead to heavy weathering of the samples. However, on the basis of the analyses carried out in non‐weathered areas, the typical composition is PbO 55–65 wt%, SiO₂31–35 wt%. In tin glazes, the tin is scattered on the mass of the glaze as SnO₂crystals with a concentration of 7–14 wt%. Concerning the decorations, it is established that the green colour is due to the presence of copper, while manganese is responsible for the brown colour. These pigments, which represent the typical colours of ‘archaic majolica’, are spread through the glaze homogeneously, apart from one case in which there is clear evidence of manganese oxide crystals.     

GC–MS ANALYSIS OF LIPIDS IN PREHISTORIC ROCK PAINTS AND ASSOCIATED OXALATE COATINGS FROM THE LOWER PECOS REGION,TEXAS*

The presumption that lipids were used as binders/vehicles in pictograph paints from southwestern Texas was tested using gas chromatography–mass spectrometry (GC–MS). A one‐step transesterification/derivatization procedure was used to convert bound and unbound fatty acids to fatty acid methyl esters for the analysis. Approximately 30 organic compounds were detected in the natural rock coating that encapsulates the paints, but there were no compounds unique to the paints. Moreover, the C_16:0 and C_18:0 concentrations in the paint samples were similar to the concentrations of these fatty acids in the rock coating, indicating that the compounds are native to the patina. Thus, lipid binders were either not used in the original paint mixture or have since degraded.     

Wall Paintings from the Roman Emona (Ljubljana,Slovenia): Characterization of Mortar Layers and Pigments

This study concerns the investigation of mortar layers and pigments of wall paintings from the Roman town of Emona (Ljubljana, Slovenia). Fragments of wall paintings consist of up to three preserved mortar layers. The mineralogical–petrographic compositions of the mortars were determined by means of optical microscopy and FT–IR spectroscopy. The investigated samples were divided into several groups based on similar thicknesses of the mortar layer, the binder colour and the composition of an aggregate. Furthermore, the results of mercury intrusion porosimetry showed that mortar layers consisting of carbonate grains exhibited lower porosity with respect to layers with mainly silicate grains, which is attributed to the angular shapes of carbonate aggregate. This is in accordance with the drilling resistance measurement system test (DRMS), confirming that layers with angular carbonate grains are harder than those with addition of rounded silicate ones, due to the good packing effect. The wall paintings were mainly executed using the fresco technique, while for some details secco was used. The identified pigments were red and yellow ochre, green earth, Egyptian blue, carbon black and lime white; all of them belonged to the so‐called austere pigment, which is quite common in Roman wall paintings.