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This note focuses on recent discussions on gemstone amulets from Late Antiquity through insights offered in two contributions to the volume Textual Amulets from Antiquity to Early Modern Times: The Shape of Words (Theis and Vitellozzi 2022). After a general presentation of the volume, I turn to the first two chapters, penned each by one of the volume's editors. Paolo Vitellozzi's paper examines the evolution of the textuality of magical gems in light of speech act theories and taxonomies elaborated in earlier secondary literature. Vitellozzi also analyses the complex interaction of medium (the gemstone), text and image in the course of this evolutionary process, showing how writing progressively assumed magical efficacy. In the following paper, Christoffer Theis analyses a specific category of magical gems, namely those which represent divinities with multiple heads. Theis' observations implicitly complement Vitellozzi's conclusions on the textuality of gemstone amulets. In the final paragraphs of this note, I briefly comment on Christian amulets and isopsephisms. [ABSTRACT FROM AUTHOR]

The suggestion in this paper tackles the uncertainty of choosing the best analysis and selection of high-quality gemstones based on multiple specific criteria of quantitative and qualitative nature. In this paper, we use the fuzzy analytic hierarchy process (F-AHP) in order to make the right decision to know the quality of the gemstone. This method is based on an effective algorithm through comparisons between the characteristics of the stones and their weight. F-AHP applies in this work to select one criterion from five criteria (specific gravity, color, clarity, cleavage, and Hardness). From the outcome, we note the hat standard of gem size is not always the best standard as seen by some researchers, and we found that small-sizzled stones are sometimes better effective and more flexible than others. Through this study, we note that the method helps reduce bias in decision-making, and method the comparisons are converted into numerical values that are processed and compared within with hierarchy that is related to the fuzzy logic with the property of uncertainty. All computations are applied by MATLAB language. [ABSTRACT FROM AUTHOR]

In the Ancient World illness was thought to be the effect not of accidental or natural causes, but rather the result of a negative agency, an external attack on the victim’s body. This paper focuses on the diverse strategies used in healing magic attested in the material and textual records from the ancient Near East to Late Antiquity, with special attention paid to how the cultural status of objects and substances was changed through ritual, a process that, along with the invocations of demons and gods, allowed objects to acquire agency to counterattack the harm inflicted on the victim’s body. [ABSTRACT FROM AUTHOR]

Highlights • Gemstones and (re)production of the tainted image of post-conflict locations. • Gemstone origin as a major value determinant. • Swat emerald and post-conflict development opportunities and place promotion. • Preventing future conflicts in Swat through fostering economic resilience. Abstract This paper critically examines the social dynamics of emerald mining in the Swat Valley and its impact on the broader gemstone processing sector in Pakistan. In particular, it pays attention to problematizing the existing structure of artisanal, small-scale emerald mining, and its fragmented supply chain that grapples with a branding stigma of gem origin. It also considers an export-led beneficiation industry within Swat to generate sustainable livelihoods and help prevent future conflicts through fostering economic resilience. The paper emerges with inferences that while the literature on colored gemstones is increasingly critical of fragmented supply chains, it should also consider the role that gemstones can play, as a constitutive and representational force, toward (re)production and (re)engineering of the "tainted" image of post-conflict locations. This is particularly the case because gemstone origin is a major factor in value determination. Areas of conflict that have previously caused negative branding of gemstones can later be transformed into post-conflict development opportunities and lead to positive branding. Approaches for pursuing such a strategy are explored in the context of Pakistan's emerald industry. [ABSTRACT FROM AUTHOR]

[Display omitted] Ruby is a mineral in the corundum (Al 2 O 3) family and it is remarkably valuable as a gemstone. From the physics point of view, the ruby coloration depends on the balance of trace or chromophore impurities and defect complexes in the Al 2 O 3 lattice. Shifting this balance into right direction is of paramount importance for the ruby value as the gemstone and ion implantation can be applied for this purpose. Thus, in the present study, we explored the influence of high dose oxygen ion implants on the natural ruby coloration. By performing quantitative colorimetry analysis, we detected prominent coloration changes unambiguously attributed to the effect of the implants, even though the implanted oxygen profile was located at the near surface region of the sample. Moreover, applying near surface sensitive cathodoluminescence measurements we observed spectacular changes in the spectra correlated with the implants. Importantly, the trends observed in the colorimetry and cathodoluminescence as a function of the implantation parameters were consistent. As such, the present paper provides both the scientific perspective and quantitative interpretations potentially paving the way for the ion beams applications in the gemstone industry. [ABSTRACT FROM AUTHOR]

In the Delanta-Dawunt district of Ethiopia's northern eastern Amhara region, twenty-one different environmental samples (gemstones) were gathered. This is one of the opal-mining (gemstone) locations in Ethiopia. We divided the 21 obtained samples into seven groups. The study's major goals were to quantify the activity concentration of gemstones (opals) and examine the health implications. For 226Ra, the activity concentration ranged from 11.97 ± 2.46 to 62.44 ± 14.99 Bq kg−1, 25.69 ± 3.69 to 137.84 ± 13.23 Bq kg−1 for 232Th, and 184.84 ± 3.59 to 968.56 ± 18.16 Bq kg−1 for 40K. 226Ra, 232Th, and 40K were found to have mean radioactivity concentrations of 29.84 ± 6.53, 68.44 ± 18.94, and 390.87 ± 6.09 Bq kg−1, respectively. Radium equivalent activity (Raeq), absorbed dose, annual effective dose equivalent, external and internal radiation hazard (Hex and Hin) index, and activity utilisation index have mean values of 151.68 19.46 Bq kg−1, 72.19 8.48 nGy h−1, 0.07 0.01mSv y−1, 0.43, 0.51, 0.57 0.08, and 0.29 0.03. 232Th has higher specific activity than the global average, while 40K has the same. Meanwhile, the absorbed dose is higher than the world's means value. The average value of excess life cancer risk found in this study is the same as the world's average value. [ABSTRACT FROM AUTHOR]

Abrasive water jet (AWJ) machining is characterized by its versatility, i.e., it can be applied to a wide variety of materials. Currently, one important application is for manufacturing gem artifacts, especially agate, which is the largest gemological material produced in the state of Rio Grande do Sul. However, one of the main obstacles to its popularization is the cost associated with the process, due to the high abrasive consumption required for a good quality surface finish. In this sense, this research paper presents a study of the influence of the main process parameters (traverse speed and abrasive mass flow rate) on the surface finish of agates machined by AWJ. The experimental procedure used three different traverse speeds, four abrasive mass flow rate in two different thicknesses of agate's plates. Surface roughness and angle of striation marks were observed for different depths from the jet entrance surface. Results were analyzed using analysis of variance (ANOVA). Through the study, it was found that the machined surface finish varies according to the depth from the entrance surface of the abrasive jet. Also, it was concluded that the surface finish of the machined surface by AWJ (surface roughness and striation marks) of the agate's plates machined by AWJ exhibits similar results for both thicknesses tested. ANOVA showed that the traverse speed is more significant than abrasive mass flow rate for the material studied with respect to the surface finish. Thus, for a small material thickness, it is possible to use high traverse speed and low abrasive mass flow rate which makes the process more economical. [ABSTRACT FROM AUTHOR]

Spectroscopic and microstructural studies of ruby variety corundum samples of Sinapalli, Odisha have been carried out using various physical techniques. FTIR, Micro Raman, photoluminescence along with microstructural and energy dispersive x-ray spectroscopy (EDAX) data reveal presence of hydroxylated form of alumina on the surface with presence of Cr chromophores. These gemstones contain zircon and rutile inclusions. Upon heat treatment, the colour of the ruby variety of gemstones improved by dissolving rutile inclusion inside the corundum lattice. Detailed data of the both untreated and heat treated samples are discussed in this paper. [ABSTRACT FROM AUTHOR]

Gemstones are minerals of gem qualities used for adornment and decoration with the attributes of beauty, durability and rarity. Traditionally, although China has been regarded as the most important source for nephrite, over the past decades, a large variety of gemstone resources have been newly discovered in China owing to continuous exploration works. The vast land with various geological and geochemical backgrounds is rich in gemstone resources with potential for new deposits discoveries. In pegmatites, gemstones are related to granitic magma events and mainly occur in pegmatitic cavities, such as tourmaline, aquamarine, spodumene, spessartine, moonstone, quartz, apatite, and topaz. The eruption of Tertiary basaltic magma provides gem-quality sapphire, spinel, olivine, garnet, and zircon. The supergene oxidation zones of some copper and iron deposits in Hubei and Anhui province host gem-quality turquoise and malachite. Moreover, the formation of the nephrite deposit in China is mostly related to the carbonatite and serpentinite rocks involved in the metamorphic-metasomatic processes. This paper comprehensively introduces the distribution of gemstones deposits, as well as the gemological and mineralogical characteristics of gemstones in China. Our present investigation provides insights into the gemstone potential of China for further exploitation. [ABSTRACT FROM AUTHOR]

In this paper, a technique is proposed for the rendering of transparent objects interactively using the method of refractive rendering. In the proposed technique, the refractive rendering algorithm is performed in two stages, namely the pre-computation stage and the shading stage. In the pre-computation stage, ray-traced information, including directions and positions of rays, are generated by a ray tracing process and are stored in a set of ray lists. In the shading stage, these data are retrieved from the ray lists for computing the shading of an object. Using the proposed technique, photorealistic image of transparent objects and gemstones with various cuttings, material properties, lighting and background can be rendered interactively. By combining the refractive rendering technique with conventional shading techniques, jewelry and crystal designs can be rendered at a much higher speed comparing with conventional ray tracing techniques. [ABSTRACT FROM AUTHOR]

Corporeality permeates the concept of something as seemingly disembodied as minerals or the earth, as we naturally perceive our surroundings through the prism of our own bodily experience. Using the examples of two objects from late antique and early Islamic Egypt, traditionally categorized as "magical" objects, it is illustrated here how corporeality permeates the perception of earth and stones in a particular historical context. The first object examined is a black hematite stone, which most likely served to protect against or stop excessive (typically gynecological) bleeding. The second is a papyrus with a so-called judicial curse, according to which those who transgressed against the inflictor of this curse were to be swallowed by the throat of the earth. [ABSTRACT FROM AUTHOR]

In this paper, Nanoparticle-Enhanced Laser Induced Breakdown Spectroscopy is applied to transparent samples and gemstones with the aim to overcome the laser induced damage on the sample. We propose to deposit a layer of AuNPs on the sample surface by drying a colloidal solution before ablating the sample with a 532 nm pulsed laser beam. This procedure ensures that the most significant fraction of the beam, being in resonance with the AuNP surface plasmon, is mainly absorbed by the NP layer, which in turn results the breakdown to be induced on NPs rather than on the sample itself. The fast explosion of the NPs and the plasma induction allow the ablation and the transfer in the plasma phase of the portion of sample surface where the NPs were placed. The employed AuNPs are prepared in milliQ water without the use of any chemical stabilizers by Pulsed Laser Ablation in Liquids (PLAL), in order to obtain a strict control of composition and impurities, and to limit possible spectral interferences (except from Au emission lines). Therefore with this technique it is possible to obtain, together with the emission signal of Au (coming from atomized NPs), the emission spectrum of the sample, by limiting or avoiding the direct interaction of the laser pulse with the sample itself. This approach is extremely useful for the elemental analysis by laser ablation of high refractive index samples, where the laser pulse on an untreated surface can otherwise penetrate inside the sample, generate breakdown events below the superficial layer, and consequently cause cracks and other damage. The results obtained with NELIBS on high refractive index samples like glasses, tourmaline, aquamarine and ruby are very promising, and demonstrate the potentiality of this approach for precious gemstones analysis. [ABSTRACT FROM AUTHOR]

Recently found historical jewellery (Czech Republic) was subjected to detailed analyses to determine the gem inlays and the gold framework in which they are embedded. Such find fits into European jewellery archaeological artefacts containing similar stones from around the fifth century CE. The gemstones were analysed with optical microscopy and Raman micro-spectroscopy to determine their mineralogical characteristics and to find out typical structural-chemical differences based on which their provenance can be found. The results of this measurement discovered two main types of minerals from the garnet group, almandine and pyrope, where pyropes have been identified as Bohemian garnets thanks to the typical photoluminescence (PL) of chromium and vanadium impurities. The craftsmanship and processing of the goldsmith work were studied using X-ray computed tomography. Such a technique is an excellent contribution for detecting and visualising the internal parts hidden behind the placement of the stones. For this reason, 3D visualisation was used to describe and better understand all preserved parts. According to this object's very high cultural and historical value, the chosen methods are suitable for non-destructive study while proving to be essential to deepen our knowledge in archaeometric investigations focused on jewellery from Late Antiquity (with possible application to the jewellery from other periods). Based on the findings presented in this study, it is one of the world's oldest documented items using Bohemian garnets in jewellery. These findings underscore the tremendous economic and political importance of Bohemian garnet mineral resources altogether, with a second completely different type of garnet believed to have originated in distant India or Sri Lanka that was used in jewellery across Europe in Late Antiquity. [ABSTRACT FROM AUTHOR]

Abstract: The gemstones, covering the spectrum from jeweler's to showcase quality, have been presented in a tripartite subdivision, by country, geology and geomorphology realized in 99 digital maps with more than 2600 mineralized sites. The various maps were designed based on the “Chessboard classification scheme of mineral deposits” proposed by Dill (2010a, 2010b) to reveal the interrelations between gemstone deposits and mineral deposits of other commodities and direct our thoughts to potential new target areas for exploration. A number of 33 categories were used for these digital maps: chromium, nickel, titanium, iron, manganese, copper, tin–tungsten, beryllium, lithium, zinc, calcium, boron, fluorine, strontium, phosphorus, zirconium, silica, feldspar, feldspathoids, zeolite, amphibole (tiger's eye), olivine, pyroxenoid, garnet, epidote, sillimanite–andalusite, corundum–spinel−diaspore, diamond, vermiculite–pagodite, prehnite, sepiolite, jet, and amber. Besides the political base map (gems by country) the mineral deposit is drawn on a geological map, illustrating the main lithologies, stratigraphic units and tectonic structure to unravel the evolution of primary gemstone deposits in time and space. The geomorphological map is to show the control of climate and subaerial and submarine hydrography on the deposition of secondary gemstone deposits. The digital maps are designed so as to be plotted as a paper version of different scale and to upgrade them for an interactive use and link them to gemological databases. [Copyright &y& Elsevier]

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The reliquary bust of Saint Lambert, hosted in the Treasure of the Liège Cathedral, was produced in the early 15th century. This exceptional goldsmithery piece is covered with gold‐coated silver, and decorated by approximately 400 stones, analysed by Raman and pXRF techniques to determine their mineralogical and chemical composition. The results confirm the identification of one hundred pearls, twenty‐six rock crystals, ten amethysts, two diamonds, and numerous glass beads with a green, blue, colourless, turquoise, orange or red colour. The glass beads show a soda‐lime composition, confirming that they are contemporary of the bust and imported from Venice, as reported by historical sources. Orange beads show a lead composition and the red stone a triplet with quartz, indicating that they were added to the bust later. The cutting of gems and beads shows also a significant evolution. The metal contains approximately 60% of Au and 40% of Ag. The origin of gemstones was difficult to establish, due to the absence of characteristic trace elements, but the chemical elements used for the manufacture and colouring of the beads were determined. This study confirms the trade of stones between Liège and Venice during medieval times. [ABSTRACT FROM AUTHOR]

Greco-Roman culture classified a great variety of gems. Authors such as Theophrastus, Plutarch and Pliny the Elder dealt with the subject. To know which gems were most highly valued in ancient Rome, it is essential to consult book 37 of Pliny the Elder. Book 37 of Pliny's Natural History is one of the few accounts on precious stones, gems and amber that collects information from various sources of antiquity, which in many cases have survived only thanks to Pliny's transcription. He catalogued the most prestigious gems, and discussed their origin, their exploitation techniques, their properties and their etymology. This corpus collects a total of 240 different variants of gems, of which, in 93 cases, its place of origin is known. In order to know to what extent the words of Pliny reflect the reality of the Roman market, we have analyzed as examples ten catalogs of modern collections of gems from various places and compared them with Pliny's comments. This analysis confirms the fact that the urban Roman elites valued precious stones extracted from the territories beyond the Roman Empire, especially those of the East. The ten catalogues contain more than 4000 different gems and glasses. It compares the information in Pliny's book on gems with ten current catalogs of various museums, adding more than 4000 analyzed copies. Both of these sources similar results and therefore confirms the interest of the Romans for these productions. [ABSTRACT FROM AUTHOR]

Certain hard and normally opaque minerals, both rare and common, occasionally crystallize as transparent or partly transparent ‘gem’ crystals. Such stones, designated ‘crystalline coloured gemstones’ (CCGs), form under highly constrained just-so ‘Goldilocks’ conditions that did not exist prior to the last supercontinent cycle. One set of gem-forming conditions arises during continent-to-continent collisions. Another comes into existence during the breakup of continents and produces distinctively different gems. Over 50 different CCG-forming metamorphic and pegmatitic minerals of the first type crystallize in certain orogenic areas near the edges of continents. In East Africa, the Himalayas, Pamirs and Hindu Kush, groups of CCG deposits formed near the leading edge of the upper plate during the collisions, and are associated with large scale circular arcs. Gems of the second type, which are for the most part blue-green-yellow magmatic sapphires, occur in conjunction with continental volcanism in eastern Australia, far eastern Russia, eastern China, Laos, Vietnam, Thailand, Rwanda, Cameroon, Nigeria and elsewhere. Orogeny causes deep fractures to be regenerated upward into younger rocks. CCG deposits of the first type are systematically associated with ancient fractures originating from below, vestiges of the Earth’s early history. Fractures may be older than the rocks in which they are observed. [ABSTRACT FROM AUTHOR]

A miniature lightweight portable Raman spectrometer and a palm-sized device allow for fast and unambiguous detection of common gemstones mounted in complex jewels. Here, complex religious artefacts and the Ring Monstrance from the Loreto treasury (Prague, Czech Republic; eighteenth century) were investigated. These discriminations are based on the very good correspondence of the wavenumbers of the strongest Raman bands of the minerals. Very short laser illumination times and efficient collection of scattered light were sufficient to obtain strong diagnostic Raman signals. The following minerals were documented: quartz and its varieties, beryl varieties (emerald), corundum varieties (sapphire), garnets (almandine, grossular), diamond as well as aragonite in pearls. Miniature Raman spectrometers can be recommended for common gemmological work as well as for mineralogical investigations of jewels and cultural heritage objects whenever the antiquities cannot be transported to a laboratory. This article is part of the themed issue ‘Raman spectroscopy in art and archaeology’. [ABSTRACT FROM AUTHOR]

Expeditions to procure gemstones from mines in Egypt's marginal territories during the Middle Kingdom (c. 2055-1650 BC) are generally perceived as representing centralized, bureaucratized and hierarchical missions to essentially monopolized resources. Traditional ‘top-down’ approaches to the social context of mining in this period assume the pivotal role of the state in controlling such endeavours through large-scale centrally organized expeditions, as deduced from the epigraphic record. This article advances a ‘bottom-up’ approach to gemstone mining in the Middle Kingdom by the deployment of cross-cultural and cross-level theories in social archaeology to micro-level production data at three key mining sites in Egypt's marginal territories. Strategies of engagement and negotiation at local levels to get access to a local labour force and the source, rather than monopolization and state controlled procurement, are forwarded as significant aspects of Middle Kingdom gemstone mining outside the Nile Valley. Feminine imagery at gemstone mines may have constituted a ritual and symbolic device to foster solidarity and cohesion among a local labour force in Egypt's marginal zones. [ABSTRACT FROM AUTHOR]

Gemstones form in metamorphic, magmatic, and sedimentary rocks. In sedimentary units, these minerals were emplaced by organic and inorganic chemical processes and also found in clastic deposits as a result of weathering, erosion, transport, and deposition leading to what is called the formation of placer deposits. Of the approximately 150 gemstones, roughly 40 can be recovered from placer deposits for a profit after having passed through the "natural processing plant" encompassing the aforementioned stages in an aquatic and aeolian regime. It is mainly the group of heavy minerals that plays the major part among the placer-type gemstones (almandine, apatite, (chrome) diopside, (chrome) tourmaline, chrysoberyl, demantoid, diamond, enstatite, hessonite, hiddenite, kornerupine, kunzite, kyanite, peridote, pyrope, rhodolite, spessartine, (chrome) titanite, spinel, ruby, sapphire, padparaja, tanzanite, zoisite, topaz, tsavorite, and zircon). Silica and beryl, both light minerals by definition (minerals with a density less than 2.8–2.9 g/cm3, minerals with a density greater than this are called heavy minerals, also sometimes abbreviated to "heavies". This technical term has no connotation as to the presence or absence of heavy metals), can also appear in some placers and won for a profit (agate, amethyst, citrine, emerald, quartz, rose quartz, smoky quartz, morganite, and aquamarine, beryl). This is also true for the fossilized tree resin, which has a density similar to the light minerals. Going downhill from the source area to the basin means in effect separating the wheat from the chaff, showcase from the jeweler quality, because only the flawless and strongest contenders among the gemstones survive it all. On the other way round, gem minerals can also be used as pathfinder minerals for primary or secondary gemstone deposits of their own together with a series of other non-gemmy material that is genetically linked to these gemstones in magmatic and metamorphic gem deposits. All placer types known to be relevant for the accumulation of non-gemmy material are also found as trap-site of gemstones (residual, eluvial, colluvial, alluvial, deltaic, aeolian, and marine shelf deposits). Running water and wind can separate minerals according to their physical-chemical features, whereas glaciers can only transport minerals and rocks but do not sort and separate placer-type minerals. Nevertheless till (unconsolidated mineral matter transported by the ice without re-deposition of fluvio-glacial processes) exploration is a technique successfully used to delineate ore bodies of, for example, diamonds. The general parameters that matter during accumulation of gemstones in placers are their intrinsic value controlled by the size and hardness and the extrinsic factors controlling the evolution of the landscape through time such as weathering, erosion, and vertical movements and fertility of the hinterland as to the minerals targeted upon. Morphoclimatic processes take particular effect in the humid tropical and mid humid mid-latitude zones (chemical weathering) and in the periglacial/glacial and the high-altitude/mountain zones, where mechanical weathering and the paleogradients are high. Some tectono-geographic elements such as unconformities, hiatuses, and sequence boundaries (often with incised valley fills and karstic landforms) are also known as planar architectural elements in sequence stratigraphy and applied to marine and correlative continental environments where they play a significant role in forward modeling of gemstone accumulation. The present study on gems and gemstone placers is a reference example of fine-tuning the "Chessboard classification scheme of mineral deposits" (Dill 2010) and a sedimentary supplement to the digital maps that form the core of the overview "Gemstones and geosciences in space and time" (Dill and Weber 2013). [ABSTRACT FROM AUTHOR]