XRF Spectrometry Research Articles

Low-temperature catalytic oxidation of ethanol over doped nickel phosphates.

This work is focused on the synthesis and performance of Ni3(PO4)2-based catalysts doped with Cu, Co, Mn, Ce, Zr, and Mg for the complete oxidation of ethanol, aiming at reducing emissions from ethanol-blended gasoline. Nickel phosphate was prepared via the co-precipitation method, followed by impregnation with the specified dopants. The catalysts were thoroughly characterized by XRD, N2-physisorption, XRF, FTIR and Raman spectroscopy, FESEM, NH3-TPD, CO2-TPD, and H2-TPR to explain their performance. All catalysts achieved complete ethanol conversion (100%) at a temperature below 320°C. The performance of the catalysts was strongly influenced by the dopant type of which Co, Ce, Mn, and Mg showed high CO2 selectivity (selectivity > 90% at 95% ethanol conversion temperature (T95)). The mechanism of oxidation is affected by the acido-basicity of the catalysts and the redox properties leading to a reaction through ethylene formation over the acid catalysts and acetaldehyde over the basic catalysts. The redox properties of the doped catalysts play a crucial role in enhancing the catalytic activity and selectivity toward CO₂, as the redox-active dopants facilitate the activation of oxygen species, which are essential for the complete oxidation of ethanol. In particular, Co and Ce demonstrated superior redox characteristics, facilitating the conversion of intermediate species and leading to higher CO2 selectivity while minimizing undesirable by-products.

High‐resolution analysis of sediments from Eighteen Mile Swamp (eastern Australia) records its transition from a fluctuating coastal lagoon to stable freshwater swamp

ABSTRACTThis research documents the paleoenvironmental evolution of Eighteen Mile Swamp on North Stradbroke Island (Minjerribah), Australia, from oscillating coastal lagoon into stable freshwater swamp over the last ca. 1600 years. We analyzed multiple sediment cores via physical description, acid sulfate soil assays, particle size analysis, diatom and pollen assemblages, photosynthetic pigment content, and Itrax XRF spectrometry, alongside ground‐penetrating radar cross‐sections. This provided a detailed ecological, geochemical and chronological framework, derived from radiocarbon, Pu and 210Pb dating, for the wetland's evolution. Results indicate spatial complexity in the timing of a pronounced shift in sedimentary conditions between ca. 300 and 1000 years ago, from estuarine mud to freshwater peat, marked by abrupt chemical and ecological changes. Unexpectedly, there were at least three and potentially many periods of dominant freshwater influence within the primarily estuarine phase, suggesting episodic estuarine closure and freshening by groundwater influx. Results provide critical insights into the complex response of subtropical wetland systems to environmental change, emphasizing the importance of interdisciplinary approaches in understanding both sedimentologic and geomorphic responses in coastal wetlands, and their potential vulnerability to future climate change. The study of Eighteen Mile Swamp is significant as it provides a detailed paleoenvironmental reconstruction that documents the wetland's evolving nature over the past two millennia. This research highlights the importance of understanding historical responses of wetlands to environmental changes, which helps inform their current and future management, conservation and restoration efforts, particularly in the context of climate change and human impacts. This study also serves as a tribute to the late Lynda Petherick, acknowledging her contributions in this field.

Bimetallic Mesoporous MCM-41 Nanoparticles with Ta/(Ti, V, Co, Nb) with Catalytic and Photocatalytic Properties.

Bimetallic (Ta/Ti, V, Co, Nb) mesoporous MCM-41 nanoparticles were obtained by direct synthesis and hydrothermal treatment. The obtained mesoporous materials were characterized by XRD, XRF, N2 adsorption/desorption, SEM, TEM, XPS, Raman, UV-Vis, and PL spectroscopy. A more significant effect was observed on the mesoporous structure, typically for MCM-41, and on optic properties if the second metal (Ti, Co) did not belong to the same Vb group with Ta as V and Nb. The XPS showed for the TaTi-MCM-41 sample that framework titanium is the major component. The new nanoparticles obtained were used as catalysts for oxidation with hydrogen peroxide of olefinic compounds (1,4 cyclohexadiene, cyclohexene, styrene) and photodegradation of organic pollutants (phenol, methyl orange) from water. The results showed improvementsin activity and selectivity in oxidation reactions by the addition of the second metal to the Ta-MCM-41 catalyst. The slow addition of H2O2 was also beneficial for the selectivity of epoxide products and the stability of the catalysts. The band gap energy values decreased in the presence of the second metal, and the band edge diagram evidenced positive potential for all the conduction bands of the bimetallic samples. The highestlevels of photocatalytic degradation were obtained for the samples with TaTi and TaV.

Pyrolysis char from waste tyres its characteristics, upgrading and application

The pyrolysis of waste tyres can recycle energy and produce reusable products (oil, char and gas). Although there are many reviews in the literature in regard to the pyrolysis characteristics of waste tyres, but this paper critically looked as pyrolysis char as one of the useful product. Its physical characteristics include pore diameter, pore volume, specific surface area, and composition. The common detection techniques of the physical characteristics include elemental analysis, proximate analysis, SEM, EDS, TGA, XRF, BET, and Raman spectroscopy. The chemical characteristics of tyre char mainly include calorific value, the surface functional groups (i.e phenols, alcohols, carboxylic acid and C-O/C-O-C chemical structures) which can be determined by FT-IR, XRD. The higher sulfur retention on the surface of tyre char is obtained at low temperature compared with that obtained at high temperature. Tyre char could also be directly used as a catalyst material to decrease the operational cost, and improve the quality of pyrolysis oil and gas. The modified tyre char with high specific surface area and lower ash content could be used as an activated carbon adsorbent material, catalyst and catalyst support, capacitor electrode to create higher commercial value, as an adsorbent, in batteries and so on. It is suggested that the recycling applications of tyre char should be developed, which can create a high level of potential economic prospects for the waste tyre pyrolysis industry.

Direct, rapid, non-destructive and 'white' multielemental toxicological analysis of hazardous elements with health risk assessment in candies and wrappers from Polish flea markets using portable XRF spectroscopy.

Elemental analysis of solid candy and wrapper samples from Polish flea markets was conducted using portable X-ray fluorescence (pXRF), a fast, cost-effective, and non-destructive technique. Hazardous elements were detected in candies, including Ni (5.20 ± 0.56 μg/g), Fe (17.28 ± 1.03 μg/g), Ba (41.23 ± 7.10 μg/g), Cr (9.63 ± 2.30 μg/g), Cd (0.56 ± 0.33 μg/g), and Cu (7.30 ± 1.15 μg/g), while wrappers contained high levels of Ti (13073.31 ± 106.80 μg/g), Sb (158.29 ± 5.28 μg/g), and Ba (2081.01 ± 36.42 μg/g). Health risk assessments showed Ni and Cd exceeding acceptable limits, posing risks for children consuming three candies daily. Non-carcinogenic risks from Ba and Cd also surpassed provisional tolerable weekly intake (PTWI) values. Minimal migration between wrappers and candies was observed, but extreme conditions may increase contamination. The study highlights the need for stricter food safety regulations and adoption of pXRF for rapid, non-invasive detection of hazardous elements.

Scaled-up Processes for the Preparation of Enhanced Antibacterial ZnO-Menthol, ZnO-Chitosan, and ZnO-Triclosan Flake/Spine-like Nanocomposites, and their Biocompatibility and Toxicity Studies

Introduction: Nanomaterials, especially their biocompatibilities and toxicities, have not been studied and their integration in real applications is still limited. Method: This paper addresses this gap by focusing on the development of antibacterial nanomaterials by combining flake/spinal ZnO nanostructures with organic antibacterial agents (menthol, chitosan, and triclosan). We systematically study their biocompatibility and toxicity, intending to apply them practically on fabric surfaces. Result: Based on the known photocatalytic and antibacterial properties of ZnO, our hypothesis suggests that the unique flake/spine ZnO nanostructures can further improve the antibacterial efficacy through induced mechanistic approaches. The synergistic effect achieved by combining ZnO with menthol, chitosan, and triclosan improves the overall bactericidal ability. XRD, XRF, FTIR, SEM, and UV-visible spectroscopy are used to characterize the nanocomposites. The antibacterial properties of the modified fabrics are tested using standard spread plate techniques. Biocompatibility and toxicity studies using a mouse model provide a comprehensive picture of the safety profile. Conclusion: This work advances the understanding of antibacterial nanomaterials, and paves the way for their wider manufacturing and practical use in textiles, meeting the industrial needs of antimicrobial clothing and wound dressings.

SYNTHESIS AND CHARACTERIZATION OF NANOPARTICLES FROM COAL FLY ASH

In this study, amorphous nanoparticles were extracted from fly ash using a sol-gel method. The obtained nanoparticles were characterized using XRF spectroscopy, XRD, FT-IR and TEM. The XRD curves show the presence of both crystalline and amorphous phases. FT-IR analysis indicated the presence of silanol and siloxane groups. Upon analysis, the primary nanoparticles were found to exhibit a roughly spherical shape with an average size of approximately 65 nm. The findings of this study demonstrate the feasibility of applying the sol-gel method to synthesize nanoparticles derived from coal fly ash (CFA), thereby avoiding other expensive and energy-intensive methods of nanoparticle synthesis.

Glass Finds from the Elite House of Roue, a Sasanian City Building in Western Iran: Composition and Classification Using XRF and Raman Spectroscopy

The Silk Road connected the east of Iran to the western world. Roue city is close to the Road. Six glass samples from Roue were classified on the basis of morphology, archaeological context and compositions. The samples were analysed by means of XRF and Raman spectroscopy and two specific groups, namely Roue type 1 and Roue type 2, with close composition to high alumina plant-ash glass in circulation from the 6th to 10th centuries CE in Mesopotamia, Iran and Syria, were identified. The simultaneous occurrence of two types of glass in the excavated layers shows that the house was inhabited in the early Islamic period. Colours (black, amber-green, light and aqua blue) were produced mainly by the amount of iron and sulphur ions required for the amber chromophore and copper ions for the blue colour and the controlling of reducing conditions in the furnace.

Black powder and mineral deposits in the LPG production and processing line: Analytical study and formation mechanisms

The accumulation of mineral deposits such as black powder causes severe impacts throughout the gas production and transport process. The phenomenon takes place from gas wells to LNG/LPG treatment plants and terminals. The complexity lies in understanding the mechanisms by which these materials are formed in random quantities, as well as their varied nature. The aim of this study is to monitor black powder and other mineral deposits formation in a chain of gas production and processing situated in the south of Algeria and unravel their root causes. To that extent, an analytical study was carried out on four samples of both mineral deposits and black powder taken from an LPG processing and production unit. The adopted analytical approach included an exploration of the textural and structural properties. It also involves a composition characterizations related to the content of metallic elements, moisture, organic and mineral matter. The particle distribution is also determined. The analytical study was conducted using gravimetric determination, XRD, XRF, SEM/EDX and Raman spectroscopy. Particle distribution was given by Laser granulometry technique. The results of the DRX/FRX and EDX characterization primarily revealed that the samples contain a variety of mineral components such as iron oxides; magnetite Fe3O4 and hematite Fe2O3, iron oxy-hydroxide FeO(OH), iron sulphide FeS2, calcite CaCO3, SiO2 and halite NaCl. The presence distribution of these components depends on the location of the sample in gas line. Granulometry study shows that black powder contamination can be spread over a wide spectrum of particle sizes ranging from 1.51 µm to 678.50 µm. This study has allowed to elucidate the nature and distribution of particles deposited at different positions in the LPG production chain and to propose probable mechanisms for their formation.

Exploring Carolingian and Romanesque cycles: a study of the detached wall paintings from the Church of St. Johann in Müstair

Twenty-six fragment of wall paintings detached from the upper register of the Carolingian and Romanesque cycles of the church of St. John in Müstair (Switzerland) have been part of the Swiss National Museum collection since the beginning of the twentieth century. As some of these objects were in a critical state of conservation, a research project was launched to assess and document their conditions, and to gain knowledge about painting materials and execution techniques, in view of planning a conservation project. In a first phase, non-destructive analyses were carried out, using handheld XRF and portable FTIR spectroscopy; followed by the targeted collection of samples for detailed analysis in the laboratory. In parallel, similar investigations were carried out on the imprints left on the walls of the church’s attic. The results allowed the identification of the pigment palette and the execution technique. Besides earth pigments such as ochres, a lime-based white, probably bianco di San Giovanni, and limited amounts of lapis lazuli were used in both painting cycles. For the Carolingian cycle, Egyptian blue and mixtures of several lead-based pigments were also identified. In several instances, the deterioration of lead-based pigments resulted in shades of grey to black severely modifying the original appearance of the wall paintings. Additionally, both cycles have suffered from pigment alteration due to fire. The obtained results, together with iconographic considerations, allowed for an extended interpretation of possible original colour palette.Graphical

Using MIR and XRF spectroscopy to develop a heavy metal leaching potential model in Irish top soils

The European Union aim to have all soils healthy by 2050. However, a major challenge to soil health monitoring is identifying key metrics for soil health indicators. Moreover, how to analyse numerous soil properties which are time-consuming, labour intensive and expensive. MIR spectroscopy is a rapid, non-destructive cheaper alternative to wet chemical methods. Here, we combined known soil properties that limit transport of heavy metals (i.e. drainage class, depth, organic matter, particle size/texture, bulk density and cation-exchange-capacity) to develop a topsoil (≤50 cm) leaching potential model (n = 3,515). The study area consisted of mostly grassland soils which had mainly high and moderately low leaching potential (43 and 36 %, respectively), with lower coverage of high and intermediate classes (10 and 11 %, respectively). However, known topsoil prediction models of 5–25 cm (n = 4759) were extrapolated to deeper samples 30–50 cm. As a result, 26 % of samples were identified as ‘out of control’ in peatland transition areas. For full spatial coverage for environmental modelling from spectral data, reference values are needed for the deeper samples in peatland transition areas.Furthermore, this study used a geological survey of the northern half of Ireland at ≤4 km2 resolution to map regions of naturally high levels of As, Cd, Cr, Cu, Ni and Pb by ICP and XRF spectroscopy. Geospatial clipping of heavy metal thresholds showed high coverage of As and Ni in Eastern regions, and Cd in the Midland regions of Ireland. Therefore, it would be useful to include fertiliser loadings, transport pathways or any source/recipient data to assess heavy metal movement throughout the soil profile, particularly in these regions.

The artefact from Kwiatków: the earliest spur featuring a zoomorphic motif from the slavic lands

Abstract In 2014, a fragment of a spur was discovered at the site in Kwiatków, Turek District, Brudzew Commune, within section G75, in mechanical layer I. This artefact likely originated from an early medieval burial ground located nearby, with its original site possibly altered due to intensive farming. The presented spur exemplifies extraordinary craftsmanship. This paper is a case study, the purpose of which is to examine the title artefact, while referencing other analogous discoveries. The uniqueness of this artefact lies in the absence of direct parallels to other objects featuring horse motifs of similar chronology. Consequently, an effort has been made to compare the spurs from Kwiatków with those of the Lutomiersk type, specimens with hooked fastenings, and artefacts unrelated to equestrian equipment. Furthermore, an analysis of the ornamentation, including its significance and manufacturing technique, has been conducted. The artefact has also undergone laboratory testing. The results obtained from XRF spectrometry, carried out at the Conservation and Dating Laboratory of the Institute of Archaeology, University of Łódź, were correlated with the results of studies of spurs from Pomerania, Silesia, the upper Elbe River area, and Moravia. Specialised examinations of the Kwiatków spur revealed the presence of zinc as an alloying element. This paper also delves into the manufacturing techniques of the Kwiatków artefact, utilising current findings on the specificity of early medieval crafts. This spur contributes to a collection of similar discoveries associated with the products of communities inhabiting the West Slavic lands. Fragmentarily preserved and lacking contextual dating, the Kwiatków spur has no precise analogues in Polish lands to date. An attempt to classify the artefact resulted in its assignment to technotype I according to J. Żak, suggesting a chronology between the 8th and 9th centuries, corresponding to the pottery found at the Kwiatków site. The presence of these materials and of the title artefact, potentially linked to an early medieval cemetery, significantly enhances our understanding of this period in history.

Noninvasive Multitechnique Analysis of Baroque Amber Artworks From Gdansk: The Benefits of Using Raman Spectroscopy

ABSTRACTThe multidisciplinary, noninvasive analysis of baroque amber artworks is part of a research project that deals with the most valuable objects from the Museum of Gdansk (Poland). The two most interesting objects will be presented here: a Baroque Gdansk wardrobe‐shaped amber cabinet (made by Johann Georg Zernebach, Gdansk, 1724) and a crucifix (Gdansk, 17th century). Macro‐ (UV, IR, and X‐radiography) and micro‐ (XRF and Raman spectroscopy) analytical methods were applied to reveal traces of old conservation treatments and uncover the techniques of the 17th and 18th century amber masters. UV photography shows the differences between the amber plates that are not so easily detected under visible light, while XRF spectrometry detects elements atypical for amber objects, suggesting previous conservation treatments. Confocal Raman measurements, especially Raman depth profiling, were performed for the amber artworks and allowed to detect areas of previous conservation treatments. Single‐point scans were collected from the surface (0 μm) to a depth of −200 μm, with a step of 50 μm. The results allowed us to identify three different types of zones: where the amber was preserved without any protective layer, places where the amber was covered with a thin layer of a protective substance, and places where amber elements were compensated for loss using a binding agent and filler. The presented project allowed the development of a comprehensive methodology for the analysis of amber objects, especially to optimize the capabilities of confocal Raman microscopy. The combination of macro‐ and microanalytical techniques made it possible to obtain a broad overview of such complex artworks while optimizing the time and effort spent on the investigations.

GGR Handbook of Rock and Mineral Analysis Chapter 6 (Part 1) Principles and Practice of X‐Ray Fluorescence Spectrometry –1: Fundamentals of XRF and Matrix Corrections

This chapter (Principles and Practice of X‐Ray Fluorescence Spectrometry – 1: Fundamentals of XRF and Matrix Corrections) is a contribution to the Geostandards and Geoanalytical Research Handbook of Rock and Mineral Analysis – an online textbook that is a fully revised and updated edition of the Handbook of Silicate Rock Analysis (P. J. Potts, 1987, Blackie, Glasgow).Chapter 6, Part 1 (from Section 2 of the handbook dealing with techniques for the determination of major and trace elements) considers the fundamentals of XRF spectrometry and matrix corrections in detail. Part 2 deals with wavelength dispersive and energy dispersive instrumentation. Following an introduction dealing with the analytical characteristics of XRF spectrometry, Part 1 continues with a detailed consideration of the origin and excitation of X‐ray spectra. Sub‐chapters that tackle the interaction of X‐rays with matter and the matrix effect in geological materials follow this. Part 1 is concluded with a mathematical treatment of the correction of absorption‐enhancement effects.

Radiological and elemental composition of cryoconite and glacier mice from Vatnajökull, Iceland

Cryoconite has been demonstrated to be an efficient accumulator of some classes of contaminants on glaciers in both mountain and polar environments, however the accumulation of contaminants in cryoconite in Iceland has received very little attention to date. To understand the spatial variability of natural and anthropogenic fallout radionuclides and metals on glaciers in Iceland, we present the first study of this region including both cryoconite from three glaciers: Virkisjökull; Skaftafellsjökull; and Falljökull, together with moss balls (‘glacier mice’) from Falljökull. The cryoconite samples and glacier mice were analysed using XRF spectrometry to assess their elemental composition and gamma spectrometry to identify, and quantify, fallout radionuclides, primarily 7Be, 137Cs, 241Am, excess 210Pb, and 40K. The results revealed that the cryoconite samples had similar compositions, influenced by local geology and natural sources of volcanic ash and dust. Higher concentrations of radionuclides and heavy metals were found in both cryoconite and glacier mice compared to control samples comprising nearby proglacial sediments. In comparison to other glaciers in the Northern Hemisphere, however, cryoconite from Icelandic glaciers contains some of the lowest activity concentrations of key radionuclides. Consequently, cryoconite deposits that are released and diluted during the melt and retreat of Icelandic glaciers are unlikely to be of environmental concern following transport to proglacial areas.

Invitro Antibacterial, Antioxidant and XRF Analysis of <i>Commelina Diffusa Burm.F. </i>Plant Extracts

Ethiopia has a long history of using medicinal herbs for treating both human and animal illnesses. Nonetheless, not enough research has been done on the antibacterial properties and possible bioactive components of the majority of medicinal plants. Therefore, this study deals with the evaluation of phytochemical, antimicrobial, antioxidant activities, phenol content and XRF analysis of <i>Commelina Diffusa Burm.F. </i>plant extracts. Mean values of the antimicrobial activity, MIC, antioxidant activities, phenol content and XRF analysis were reported as mean ± standard deviation. The chloroform leaf extracts of the plant gave the highest yield 23.4% followed by methanol 22.27%. The presence of several metabolite components, including alkaloids, diterpenes, flavonoids, glycosides, phenol, protein, saponin, steroids, tannins, terpenoids, tri-terpenoids and amino acids, has been shown by qualitative phytochemical analysis of plant parts. Significant antibacterial activity against the test bacterial strains was demonstrated by steam extracts of<i> Commelina Diffusa Burm.F. </i>Moreover, the methanolic extract of the plant demonstrated notable antioxidant activity. The highest value of phenolic content was obtained in <i>Commelina Diffusa Burm.F. </i>steam methanol extract followed by leaf extract while <i>Commelina Diffusa Burm.F. </i>root extract shows lower phenolic content. In this study, threaten elements were determined in the <i>Commelina Diffusa Burm.F. </i>plant part by using XRF spectroscopy. Overall, this research contributes to the understanding of pharmacological potential of <i>Commelina Diffusa Burm.F. </i>and highlights the importance of further exploring its medicinal properties. The findings provide valuable insights into utilizing medicinal plants for disease treatment and support the development of natural therapeutic agents.

The extraordinary universe of Peter Apian: technical investigation of five copies of a 16th-century astronomical book

In 1540, in Ingolstadt, Germany, the influential astronomer and printer Peter Apian produced the Astronomicum Caesareum: a printed and hand-coloured astronomical book visualising the Ptolemaic universe through the use of diagrams and wheelcharts, worthy of his imperial patron, Charles V. About 130 copies have survived to this day, with varying degrees of paper quality and level of decoration, and only eleven volumes are considered deluxe copies. We thoroughly analysed one deluxe volume held at the Fitzwilliam Museum, Cambridge, and compared the results with four (one deluxe and three standard) other copies from institutions in the UK. A non-invasive analytical protocol was applied, including extensive microscopy, fibre-optic reflectance spectroscopy (FORS), X-ray spectroscopy (XRF), macroscale XRF (MA-XRF) and Raman spectroscopy. The most interesting pages were chosen based on art-historical evidence and the variety of the colour palette, including on volvelles (wheelcharts) and coats of arms. Following a systematic approach, we analysed the same pages in each volume, gathering information on the colour palette in all the volumes. The type of paper and the presence of watermarks were also documented. A wide range of materials was identified in the five copies, including red, purple and yellow organic dyes, lead white, verdigris, vermilion, azurite, indigo, smalt, and lead–tin yellow. Mosaic gold was used to embellish certain paint passages in the deluxe volumes and metals (gold and silver) were applied on some pages. The comprehensive findings were essential to identify specific traits related to Apian’s workshop, to differentiate deluxe from standard copies, to suggest an order of production of the copies, and to provide new information on this landmark book and more generally in an under-researched field of study.

In-situ non destructive investigation of contemporary outdoor bronze sculptures

Indoor investigations are commonly used to assess the causes and extent of damage to bronze artwork and cultural heritage items; however, these methods typically involve destructive sampling and outdoor bronze sculptures are typically heavy and large, hindering their transport. In this study, 16 contemporary bronze sculptures exposed to outdoor environments for a period exceeding 20 years were evaluated in-situ to develop a non-destructive prediction model that can identify types of corrosion and quantify the amount of corrosion on bronze sculptures that cannot be easily transported. The sculptures were classified into three groups according to their patina chromaticity, reflectivity, and chemical composition. The corrosion characteristics were found to be copper oxide and sulfide patinas. Chromaticity and reflectivity investigations revealed that the chemical composition changes of the patinas corresponded to the formation of corrosion products, thus showing a high potential for the identification of the type of corrosion. Portable XRF spectroscopy showed that the low error rate of Cu make its compositional behavior a good indicator in identifying the type of corrosion of sulfide and chloride patinas. Portable Raman spectroscopy was able to detect basic sulfides such as brochantite, antlerite, and cuprite. The corrosion types and corrosion products on the bronze sculptures could be identified using chromaticity and reflectivity, portable X-ray fluorescence, and portable Raman spectroscopy. The rapid insitu diagnosis of these corrosion attributes is expected to contribute to establishing conservation treatment plans in the future.

Materials Analysis of Two Nineteenth-century Brazilian Polychrome Sculptures to Reveal Their History and Significance

ABSTRACT A pilot project is presented, in which two metal sculptures involved in a real case managed by the Brazilian Federal Police underwent microscopical examination and analysis by forensic scientists, including Raman and XRF spectroscopies and SEM-EDX, made possibly by damage sustained when they were vandalized. The findings are interpreted from the points of view of both materials history and material culture. Both sculptures had previously been described as patinated bronze but were found to have been cast in zinc, a popular material for sculpture in the nineteenth century, with their original patination later removed. The investigation showed that the bronze-colored polychromy then applied consisted of materials used by Brazilian Concrete artists of the 1950s and 1960s, and could be related to the re-siting of the capital of Brazil from Rio de Janeiro to Brasilia in the same period.

An Archaeometric Study of the Iron Age Ceramics from Quinta do Almaraz Archaeologic Site (8th to 5th Centuries BC)—Colour and Mineralogical Characterization

The ceramic pastes of ca. 31 samples recovered from the Almaraz archaeological site, located in the south bench of Tagus River, were studied in detail using XRF, micro-Raman and GSDR spectroscopies, as well as the XRD technique. The ceramic sherds could be grouped into six categories, red slip tableware, decorated tableware, yellow slip tableware, grey tableware, common tableware, and handmade pottery. Our studies of the mineralogic composition of the sherds’ body indicate all ceramics were produced locally, using siliceous clays in most cases and calcareous clays in a few ones. Micro-Raman and ground state diffuse reflectance absorption spectroscopy provided useful information regarding the materials used to produce the coloured ceramics: hematite and brookite for the red slip and decorated ceramics, jacobsite or carbon black for the black decoration or grey ceramics. For the yellow slip tableware, a simple engobe rich in yellow clay was used. XRF spectroscopic studies provided the elemental composition of all samples, and biplots of the potassium (K) versus calcium (Ca) contents, normalized to the silicon content of each ceramic paste, clearly show Pliocene and Miocene local clays sources were used to produce most ceramics. Only one sherd can be considered a Lisbon production.