Gems & Gemology最新文献_第2页

Color Modification of Spinel by Nickel Diffusion: A New Treatment 镍扩散法处理尖晶石的新方法

Gems & Gemology Pub Date : 2023-08-01 DOI: 10.5741/gems.59.2.164

M. Jollands, A. Ludlam, Aaron C. Palke, W. Vertriest, Shiyun Jin, Pamela Cevallos, Sarah Arden, Elina Myagkaya, Ulrika D’Haenens-Johannson, Vararut Weeramongkhonlert, Ziyin Sun

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Morphology of Colombian Emerald: Some Less-Common Cases and Their Growth and Dissolution History 哥伦比亚祖母绿的形态:一些不常见的案例及其生长和溶解史

Gems & Gemology Pub Date : 2023-05-01 DOI: 10.5741/gems.59.1.46

K. Schmetzer, G. Martayan

{"title":"Morphology of Colombian Emerald: Some Less-Common Cases and Their Growth and Dissolution History","authors":"K. Schmetzer, G. Martayan","doi":"10.5741/gems.59.1.46","DOIUrl":"https://doi.org/10.5741/gems.59.1.46","url":null,"abstract":"GEMS & GEMOLOGY SPRING 2023 In general, the morphology of Colombian emerald originating from different mines is rather simple and formed by a small number of external crystal faces. We observe two dominant planes, the basal pinacoid and the first-order hexagonal prism, occasionally in combination with small second-order hexagonal prism faces and firstand/or second-order hexagonal dipyramids (Goldschmidt, 1913; Schwarz and Giuliani, 2002; Moore and Wilson, 2016). The internal growth pattern of such samples, which normally show prismatic habit, consists of growth planes parallel to the external crystal faces (Kiefert and Schmetzer, 1991). Occasionally, natural emerald and beryl crystals show etching and dissolution features (an overview of the pertinent literature is given in box A). Other growth features are due to skeletal and polygonal growth of beryl crystals (see box B). Both growth features are related to the observations made in this article for Colombian emerald crystals. Rarely mentioned are emerald crystals with conical habit (Johnson, 1961a,b)—or vasos in the form of slightly conical empty tubes (Klein, 1941)—or emeralds in the form of prismatic, empty “cups” with planar bottoms (Weldon et al., 2016). In most references,","PeriodicalId":354281,"journal":{"name":"Gems & Gemology","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115136308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Gemological Characterization of Montana Sapphire from the Secondary Deposits at Rock Creek, Missouri River, and Dry Cottonwood Creek 岩石溪、密苏里河和干棉木溪次生矿床蒙大拿蓝宝石的宝石学特征

Gems & Gemology Pub Date : 2023-05-01 DOI: 10.5741/gems.59.1.2

Aaron C. Palke, Nathan D. Renfro, J. R. Hapeman, R. Berg

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Methods and Challenges of Establishing the Geographic Origin of Diamonds 确定钻石地理来源的方法与挑战

Gems & Gemology Pub Date : 2022-11-01 DOI: 10.5741/gems.58.3.270

Evan M. Smith, K. Smit, S. Shirey

{"title":"Methods and Challenges of Establishing the Geographic Origin of Diamonds","authors":"Evan M. Smith, K. Smit, S. Shirey","doi":"10.5741/gems.58.3.270","DOIUrl":"https://doi.org/10.5741/gems.58.3.270","url":null,"abstract":"GEMS & GEMOLOGY FALL 2022 Some famous diamonds, such as the Hope, the Cullinan, and the 404.2 ct “4 de Fevereiro” diamond in figure 1, have high-profile histories that include their geographic provenance. Other diamonds with a known origin can occasionally be sourced in the marketplace or directly from miners. But for the majority of diamonds, this information is not preserved, instead becoming obscured as they move through the supply chain. To some extent, diamond provenance has not been seen as a valuable piece of information and is not presented as a relevant pricing factor the way it sometimes is for some other gemstones. Rough diamonds are typically bought and sold in lots or parcels based on physical characteristics, including color, clarity, size, and morphology. In assembling these parcels, it is common practice to mix diamonds of similar character from different mines. Faceted diamonds are sold mainly on the basis of the 4Cs (color, cut, clarity, and carat weight) and may be mixed further. Beyond the historical or scientific interest in provenance, several recent developments have put dia mond origin at the forefront of conversations in the industry and among consumers. Initially, this was driven by a need to track conflict diamonds and prevent their entrance into the trade. Now, with mountMETHODS AND CHALLENGES OF ESTABLISHING THE GEOGRAPHIC ORIGIN OF DIAMONDS","PeriodicalId":354281,"journal":{"name":"Gems & Gemology","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115275975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sapphire Beneath the Rich Black Soil of Muling, Northeastern China 中国东北穆陵富饶黑土下的蓝宝石

Gems & Gemology Pub Date : 2022-11-01 DOI: 10.5741/gems.58.3.290

Yimiao Liu, Ren Lu

{"title":"Sapphire Beneath the Rich Black Soil of Muling, Northeastern China","authors":"Yimiao Liu, Ren Lu","doi":"10.5741/gems.58.3.290","DOIUrl":"https://doi.org/10.5741/gems.58.3.290","url":null,"abstract":"The rich black soil of Muling in northeastern China yields not only abundant crops but also glittering gem corundum. In this study, gemological quality and characteristics and provenance-related features of sapphire from Muling are first reported with comprehensive analytical results. Muling sapphire exhibits a wide spectrum of hue and saturation. Mineral inclusions (e.g., rutile, zircon, anorthite, and pyrope) as well as other distinctive internal features (e.g., polysynthetic twinning accompanied by intersecting tubes, iridescent hexagonal thin films, and angular color zoning) are identified by microscopic observation and Raman spectroscopy. Spectral features and trace element chemistry of the various colors of gem-quality Muling sapphire are analyzed by ultraviolet/visible/near-infrared spectroscopy and laser ablation–inductively coupled plasma–mass spectrometry. To assess the characteristics of Muling sapphire against well-known corundum sources worldwide, inclusion analysis and trace element discrimination diagrams are utilized. Analytical results indicate that Muling sapphire originated from a more diverse geological environment than typical magmatic or metamorphic origin. The Muling deposit shows great potential to produce fine gem-quality sapphire material.","PeriodicalId":354281,"journal":{"name":"Gems & Gemology","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127778882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Color Mechanism and Spectroscopic Thermal Variation of Pink Spinel Reportedly from Kuh-i-Lal, Tajikistan 塔吉克斯坦Kuh-i-Lal粉红色尖晶石的显色机理和光谱热变化

Gems & Gemology Pub Date : 2022-11-01 DOI: 10.5741/gems.58.3.338

Yicen Liu, Li-jian Qi, D. Schwarz, Zhengyu Zhou

{"title":"Color Mechanism and Spectroscopic Thermal Variation of Pink Spinel Reportedly from Kuh-i-Lal, Tajikistan","authors":"Yicen Liu, Li-jian Qi, D. Schwarz, Zhengyu Zhou","doi":"10.5741/gems.58.3.338","DOIUrl":"https://doi.org/10.5741/gems.58.3.338","url":null,"abstract":"The color mechanism of pink spinel from Kuh-i-Lal in the Pamir Mountains of Tajikistan was studied using photo luminescence, mid-infrared, and ultraviolet/visible spectroscopy. This included studying the variations in spectra after heating to a series of temperatures ranging from 300° to 1000°C. Laser ablation–inductively coupled plasma–mass spectrometry was used to measure the trace elements present. The results reveal that the color is caused by the combined effect of spin-allowed transitions of Cr 3+ , Fe 3+ , V 3+ , and Fe 2+ -Fe 3+ intervalence charge transfer mechanisms. The photoluminescence spectra show that during heat treatment, the intensity of the N 1 peak (687 nm) and the full width half maximum of the R-line and N-lines increase with temperature. Following heating in the range of 750°–825°C, there is a linear relationship between temperature and the ratio of integral areas of the R-line and N-lines. The mid-infrared spectra indicate that the band at 581 cm –1 ( ν 3 ) gradually disappears during the heating process, which is likely related to the variation of octahedral M-O and tetrahedral T-O bond length in the spinel lattice.","PeriodicalId":354281,"journal":{"name":"Gems & Gemology","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126376702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gems on Canvas: Pigments Historically Sourced from Gem Materials 画布上的宝石:历史上来自宝石材料的颜料

Gems & Gemology Pub Date : 2022-11-01 DOI: 10.5741/gems.58.3.318

Britni LeCroy

{"title":"Gems on Canvas: Pigments Historically Sourced from Gem Materials","authors":"Britni LeCroy","doi":"10.5741/gems.58.3.318","DOIUrl":"https://doi.org/10.5741/gems.58.3.318","url":null,"abstract":"GEMS & GEMOLOGY FALL 2022 The wearing and collecting of gems mark their bearers with powerful symbols of status and allure. Because of their high value, gems are researched with nondestructive methods to feed growing public interest in areas such as geographic origin, synthesis, and treatment. For a gemologist, causing damage to a stone is a cardinal sin. For a painter in the past, gem materials were coveted for their pigment potential. For centuries, perfectly viable gemstones met their fate between a mortar and pestle before becoming immortalized as paint on a canvas, mural, or cave wall. These pigments commemorated color as a means of communication beyond the limits of written or spoken language. Gem materials such as hematite, azurite, malachite, lapis lazuli, bone, ivory, and cinnabar have all played roles as pigments throughout history—for some, a role assumed long before their use as gem materials (figure 1). Pigment research is an important field encompassing geologists, artists, anthropologists, historians, and even gemologists who contribute their knowledge and expertise to a subject where these disciplines converge. Pigment can be defined as the component of paint that contributes color (Siddall, 2018). Natural inorganic pigments are derived from rocks or minerals that have been processed to extract and concentrate the material’s coloring agent (figure 2). Synthetic pigments are often chemically identical to their natural coun-","PeriodicalId":354281,"journal":{"name":"Gems & Gemology","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128043649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Gemological and Spectroscopic Study with Mobile Instruments of “Emeralds” from the Coronation Crown of Napoleon III 用移动仪器对拿破仑三世加冕王冠上的“祖母绿”进行宝石学和光谱研究

Gems & Gemology Pub Date : 2022-08-15 DOI: 10.5741/gems.58.2.168

S. Karampelas, E. Gaillou, Annabelle Herreweghe, Farida Maouche, Ugo Hennebois, Sophie Leblan, Bérengère Meslin Sainte Beuve, M. Lechartier, D. Nectoux, A. Delaunay

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Characteristics of Newly Discovered Amber from Phu Quoc, Vietnam 越南富国新发现琥珀的特征

Gems & Gemology Pub Date : 2022-08-15 DOI: 10.5741/gems.58.2.184

Le Ngoc Nang, P. T. Hieu, Lam Vinh Phat, P. M. Tien, Ho Nguyen Tri Man, Ha Thuy Hang

引用次数: 0

Natural Radioactivity in Select Serpentinite-Related Nephrite Samples: A Comparison with Dolomite-Related Nephrite 蛇纹石相关软玉样品中的天然放射性:与白云石相关软玉的比较

Gems & Gemology Pub Date : 2022-08-15 DOI: 10.5741/gems.58.2.196

D. Malczewski, M. Sachanbiński, M. Dziurowicz

{"title":"Natural Radioactivity in Select Serpentinite-Related Nephrite Samples: A Comparison with Dolomite-Related Nephrite","authors":"D. Malczewski, M. Sachanbiński, M. Dziurowicz","doi":"10.5741/gems.58.2.196","DOIUrl":"https://doi.org/10.5741/gems.58.2.196","url":null,"abstract":"1. these deposits The published literature offers only a few records of direct measurement of the natural radioactivity in nephrite. The present study used high-purity germanium (HPGe) low-background gamma-ray spectrometry to measure activity concentrations of primordial radionuclides in 11 serpentinite-related nephrite (ortho-nephrite) samples from deposits in Poland, Russia, Canada, and New Zealand, along with three samples of rodingite and serpentinite from a nephrite deposit in Nasławice, Poland. All nephrite samples exhibited very low 40 K, 232 Th, and 238 U activity concentrations that fell within the range of published values for ultrabasic and basic rocks. The nephrite samples from Jordanów (Poland) gave the highest uranium and thorium activity concentration values. Two samples of plagiogranitic rodingite showed significantly higher 238 U and 232 Th activity concentrations than the values measured for nephrite. Nephrite thorium and uranium concentrations correlated strongly (r = 0.98), and the corresponding Th/U ratios appear unique according to geographical location. The mean estimated potassium, thorium, and uranium concentrations from ortho-nephrite analyzed here were compared with corresponding mean values previously reported for dolomite-related nephrite (para-nephrite). The comparison indicates that the ortho-nephrites studied have similar uranium concentrations but lower mean potassium concentrations and higher mean thorium concentrations than those reported for para-nephrite in the literature.","PeriodicalId":354281,"journal":{"name":"Gems & Gemology","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116017984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gems &amp; Gemology最新文献

Gems & Gemology最新文献