110 Results Found

In the Hellenides Orogen, minerals of various gem quality occur in various rock types from mainly four tectono-metamorphic units, the Rhodope, Pelagonian, and the Attico-Cycladic massifs, and the Phyllites-Quartzites unit of Crete Island. In crystall...

The monetary value of gemstones is based on five variables: rarity, cut, weight, color and clarity. The latter refers to internal impurities and defects. Fashion may also dictate demand and price. To enhance some of these features and value, gemstone...

Laser-induced breakdown spectroscopy (LIBS), accompanied by chemometric data analysis, is used to identify and classify gemstones of various hardness. The study involves several gemstones: amethyst, aquamarine beryl, bloodstone citrine, diopside, and...

The identification of gemstones is an important topic in the field of cultural heritage, given their enormous value. Particularly, the most important precious stones, namely diamond, emerald, ruby and sapphire, are frequently subjected to counterfeit...

The study of ornament in Greek and Roman art has been the focus of increasing scholarly interest over the last decade, with many publications shedding new light on the dynamics of ornatus in antiquity, and the discourses that shaped and situated it....

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...

Gemstone samples, as objects of study in gemology, carry rich geological information and cultural value, playing an irreplaceable role in teaching, research, and public science communication. In the current age of big data, machine learning and artif...

The initial nucleus of gemstones at the Natural History Museum of the University of Florence (Italy) is linked to the significant collection of the Medici family, who began it as early as the 15th century. The present research aims to study this coll...

This paper presents a computer-vision-based methodology for automatic image-based classification of 2042 training images and 284 unseen (test) images divided into 68 categories of gemstones. A series of feature extraction techniques (33 including col...

In this study, we report the experimental findings of a multi-methodological and comparative investigation of a natural (from the Wah Wah Mountains of Beaver County, Utah) and three synthetic (hydrothermally grown) gem-quality red beryls by means of:...

To properly and quickly evaluate an object’s shape, in a manner that is suitable for real-time applications, a set of parameters has been created and the shape parametric description (SPD) has been elaborated. This solution is focused on the cl...

The Jizerka Quaternary alluvial placer in the Czech Republic has been a well-known source of gemstones since the 16th century, and the only one in Europe that has yielded a significant amount of jewel-quality sapphire. Besides Mg-rich ilmenite (&ldqu...

Gemstones usually contain inclusions as the natural hallmark of their formation. Studies on inclusions may contribute to our understanding of the gem and better adapt to the gems and jewelry industry. In this study, we applied advanced 3D Raman mappi...

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 depos...

This article analyses how a strategy for Tanzania’s tanzanite gemstone mining sector could foster gender equality in the mine-to-market (M2M) supply chain, whilst enhancing opportunities for female entrepreneurship as part of the country’...

The jaspers located in the Topçam Mountain, Tepeyurt region (Tokat, Turkey), were formed at green-colored metavolcanic levels within Permian–Triassic schists. The sizes of the jaspers generally vary from a few cm to 1.5 m, and their colo...

Emeralds require the unusual association of typically compatible elements (Cr, V), with incompatible Be to form, and occur in complex tectonic settings associated with sediments (type IIB; Colombia) or, more commonly, with magmatism and regional meta...

Absorption spectroscopy has been widely used in gemstone societies as it enables the identification of the origin and post-treatment of gemstones in a non-destructive way. The infrared (IR) range is critical for studies of gemstones such as corundum,...

Research on photoluminescence spectroscopy on Cr-doped gem materials has demonstrated great success regarding the identification of gemstones in terms of building rapid test systems. In this study, 405 nm photoluminescence spectroscopy was used to me...

The Chiaravalle Cross, a masterpiece of Mediaeval goldsmithery, went under restoration in 2016. This was a unique opportunity to undertake an in-depth multidisciplinary study. Several issues were addressed, as for example the chronology of the Cross,...

Imitation gemstone glass has numerous characteristics, including low cost, rich colour, stable colouring, and the formation of colour-changing effects that can meet the jewellery market demand for beautiful gemstones of middle and low grades. In this...

The Cathedral of Valencia, Spain, has preserved the so-called Holy Chalice of the Last Supper since 1437. It consists of a foot, a gold stem, and an upper cup carved in agate stone. Based on a pious tradition, this cup is supposed to be the one used...

The characterization of objects of historical and cultural interest represents a crucial topic, specifically when it regards gemstones. Actually, the advanced investigation of precious minerals of gemological interest requires exclusively non-destruc...

Objective: To identify the optimal dual-energy computed tomography (DECT) scanning protocol for peripheral arterial stents while achieving a low radiation dose, while still maintaining diagnostic image quality, as determined by an in vitro phantom st...

Background/Objectives: Sugemalimab demonstrated clinical efficacy in the GEMSTONE-303 trial, but its cost-effectiveness remains unclear. This study aims to evaluate the cost-effectiveness of sugemalimab in combination with chemotherapy (CAPOX) as a f...

Gem-quality green vanadium grossular (var. tsavorite) is exclusively hosted in the Neoproterozoic Metamorphic Mozambique Belt (NMMB). The geochronology of tsavorite is limited until now, and the accurate crystallization age of the tsavorite in Kenya...

This retrospective study aimed to predict the injury time of rib fractures in distinguishing fresh (30 days) or old (90 days) rib fractures. We enrolled 111 patients with chest trauma who had been scanned for rib fractures at our hospital between Jan...

The aim of this study was to explore the feasibility of quantitatively evaluating a sapphire’s color by analyzing gemstone images. The color characteristics of gemstones through photography and color extraction were accurately captured, and the...

Epithermally altered volcanic rocks in Greece host amethyst-bearing veins in association with various silicates, carbonates, oxides and sulfides. Host rocks are Oligocene to Pleistocene calc-alkaline to shoshonitic lavas and pyroclastics of intermedi...

The term “demantoid”, first proposed in 1856 by the famous Finnish mineralogist Nils von Nordensheld, refers to a highly dispersed yellow-green mineral from the Central Urals placers. In 1874, it was found to be a gem variety of andradite garnet. “Ho...

Background: This study aimed to investigate the use of spectral computed tomography (SCT) hybrid images combining virtual monoenergetic images (VMIs) and iodine maps (IMs) as a potentially efficient search series for routine clinical imaging in patie...

In this work a rare and attractive blue diopside present in Sissone valley in the Western Alps was investigated through different methodologies: geological survey; standard gemological methods; X-Ray Powder Diffraction; SEM observations; Raman spectr...

For some time, dual energy computed tomography (DECT) has been an established method used in a vast array of clinical applications, including lung nodule assessment. The aim of this study was to analyze (using monochromatic DECT images) how the X-ray...

With lung cancer being the most common malignancy diagnosed worldwide, lung nodule assessment has proved to be one of big challenges of modern medicine. The aim of this study was to examine the usefulness of Dual Energy Computed Tomography (DECT) in...

In Val d’Ala (Western Alps in Piedmont, Italy), the most interesting rocks for mineralogical research are represented by rodingite (rich in mineralized veins and fractures) associated with serpentinite in the eclogitized oceanic crust of Piedmo...

Fluorescence and phosphorescence are listed as mineral optical–physical properties in classical gemology textbooks. The trace elements which exist in gems, certain defects in the crystal lattice, and some luminous molecules contribute to lumine...

The Burano Formation in Val Secchia in the province of Reggio Emilia is rich in black or very dark quartz. The crystals are often pitted by scars, rarely shiny, often opaque, rarely translucent, and about 3 cm long. However, they have a beautiful col...

Andradite, variety demantoid, is a rare gem mineral. We describe gem-quality garnet crystals from serpentinized harzburgites from Dobšiná, Slovakia which were faceted. Both the andradite samples were transparent, with a vitreous luster and a vivid gr...

The Cathedral of Valencia has kept an important relic since 1437: the Holy Chalice of the Last Supper. It consists of an agate cup, a gold stem, and a gemstone foot. According to a pious tradition, this cup is the one used by Jesus of Nazareth to ins...

Ruby as a natural gemstone has an early history in which its colorful properties [...]

In a speedy and complicated word, only a small number of book readers have the time to dig out the hidden “gemstones” between the text lines [...]

The Desana treasure is a remarkable assemblage of items made of gold, silver, gemstones and glasses found in north-western Italy. Most scholars agree on the fact that the core of the treasure might have belonged to a single deposit resulted from a lo...

The Chinese large freshwater nucleated pearl has become popular for its unique appearance throughout the international jewelry market in recent years. However, its quality evaluation mostly depends on appearance observations, and the influence of the...

Madagascar is known as the ‘Island of Gemstones’ because it is full of gemstone resources. Apatite from Madagascar is widely popular because of its greenish blue Paraiba-like color. This study analyzes apatite from Madagascar through stan...

Currently, most of the popular spinels in the jewellery market come from Myanmar and Tajikistan. It is well known that provenance is one of the main factors affecting the value of a gemstone, and the geographic origin of a gemstone can be determined...

Tsavorite’s color is not only affected by its internal components, but also by external factors. This paper studies the neutral grey background and cutting on the impact on color. Under a 6504K fluorescent lamp, by changing the Munsell neutral...

Grossular, a widely recognized colored gemstone in the market, attains premium quality when exhibiting pale-toned orange-yellow to golden-yellow hues with high transparency. Recently, our research team identified abundant gem-grade grossular associat...

Ruby (red corundum) is one of the most prominent colored gemstones in the world. The highest-quality ruby (“pigeon blood” ruby) comes from marbles of the Mogok Stone Tract in central Myanmar. Although Mogok ruby has been exploited since the 6th centu...

The trapiche garnet, a gemstone of unparalleled beauty, boasts a rare structure comprising one core, six radiating arms, and a main body. The occurrence of garnet within the trapiche structure elevates it beyond the species, granting it significant s...

This study proposes new data on the rare pyroxene, variety violane, sampled from its type locality, Praborna manganese deposit, near Saint Marcel (Val d’Aosta, Italy). Violane is very appreciated as a gemstone for its different hues of violet-blue co...