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
{"title":"Color Modification of Spinel by Nickel Diffusion: A New Treatment","authors":"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","doi":"10.5741/gems.59.2.164","DOIUrl":"https://doi.org/10.5741/gems.59.2.164","url":null,"abstract":"","PeriodicalId":354281,"journal":{"name":"Gems & Gemology","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126194565","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}
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,
总的来说，来自不同矿山的哥伦比亚祖母绿的形态相当简单，由少量的外部晶面组成。我们观察到两个优势面，基底松状面和一阶六边形棱柱，偶尔与小的二阶六边形棱柱面和一阶/或二阶六边形双棱柱面结合在一起(Goldschmidt, 1913;施瓦茨和朱利安尼，2002;Moore and Wilson, 2016)。这类样品的内部生长模式通常表现为棱柱形习惯，由与外部晶面平行的生长面组成(Kiefert和Schmetzer, 1991)。偶尔，天然祖母绿和绿柱石晶体表现出蚀刻和溶解特征(相关文献概述见方框A)。其他生长特征是由于绿柱石晶体的骨骼和多边形生长(见方框B)。这两种生长特征都与本文中对哥伦比亚祖母绿晶体的观察有关。很少被提及的是具有圆锥形习惯的祖母绿晶体(Johnson, 1961a,b)——或略呈圆锥形的空管形式的维管(Klein, 1941)——或具有平面底部的棱柱形空“杯”形式的祖母绿(Weldon et al.， 2016)。在大多数参考文献中，
{"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}
Aaron C. Palke, Nathan D. Renfro, J. R. Hapeman, R. Berg
{"title":"Gemological Characterization of Montana Sapphire from the Secondary Deposits at Rock Creek, Missouri River, and Dry Cottonwood Creek","authors":"Aaron C. Palke, Nathan D. Renfro, J. R. Hapeman, R. Berg","doi":"10.5741/gems.59.1.2","DOIUrl":"https://doi.org/10.5741/gems.59.1.2","url":null,"abstract":"","PeriodicalId":354281,"journal":{"name":"Gems & Gemology","volume":"1 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":"129312483","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}
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
一些著名的钻石，如图1中的“希望”、“库里南”和404.2克拉的“4 de Fevereiro”钻石，有着引人注目的历史，包括它们的地理来源。其他来源已知的钻石偶尔可以在市场上或直接从矿工那里获得。但对于大多数钻石来说，这些信息并没有被保存下来，而是在它们通过供应链的过程中变得模糊不清。在某种程度上，钻石的来源并没有被视为一种有价值的信息，也没有像其他宝石那样被视为一个相关的定价因素。未经加工的钻石通常是根据其物理特性(包括颜色、净度、大小和形态)成批或包裹买卖的。在组装这些包裹时，通常的做法是将来自不同矿山的相似性质的钻石混合在一起。多面钻石的销售主要基于4c(颜色、切割、净度和克拉重量)，也可能进一步混合。除了历史或科学对钻石来源的兴趣之外，最近的一些进展也使钻石的来源成为业内和消费者讨论的焦点。最初，这是由于需要追踪冲突钻石并防止它们进入贸易。现在，通过各种方法和挑战来确定钻石的地理来源
{"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}
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.
{"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}
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.
{"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}
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-
{"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}
S. Karampelas, E. Gaillou, Annabelle Herreweghe, Farida Maouche, Ugo Hennebois, Sophie Leblan, Bérengère Meslin Sainte Beuve, M. Lechartier, D. Nectoux, A. Delaunay
{"title":"A Gemological and Spectroscopic Study with Mobile Instruments of “Emeralds” from the Coronation Crown of Napoleon III","authors":"S. Karampelas, E. Gaillou, Annabelle Herreweghe, Farida Maouche, Ugo Hennebois, Sophie Leblan, Bérengère Meslin Sainte Beuve, M. Lechartier, D. Nectoux, A. Delaunay","doi":"10.5741/gems.58.2.168","DOIUrl":"https://doi.org/10.5741/gems.58.2.168","url":null,"abstract":"","PeriodicalId":354281,"journal":{"name":"Gems & Gemology","volume":"693 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":"115117880","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}
Le Ngoc Nang, P. T. Hieu, Lam Vinh Phat, P. M. Tien, Ho Nguyen Tri Man, Ha Thuy Hang
{"title":"Characteristics of Newly Discovered Amber from Phu Quoc, Vietnam","authors":"Le Ngoc Nang, P. T. Hieu, Lam Vinh Phat, P. M. Tien, Ho Nguyen Tri Man, Ha Thuy Hang","doi":"10.5741/gems.58.2.184","DOIUrl":"https://doi.org/10.5741/gems.58.2.184","url":null,"abstract":"","PeriodicalId":354281,"journal":{"name":"Gems & Gemology","volume":"30 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":"132039824","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}
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.
{"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}
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