Raman and photoluminescence spectroscopy measurements were conducted on corundum and chrysoberyl in various orientations. This research primarily focused on elucidating the anisotropy of photoluminescence in gemstones and related materials. For this purpose, two classic gem materials-corundum (a uniaxial crystal) and chrysoberyl (a biaxial crystal)-were utilized. The investigation of photoluminescence anisotropy in these materials provided deeper insights into the structural characteristics of gemstones, including local symmetry environment and multisite structure. The analysis of the photoluminescence spectra revealed that both corundum and chrysoberyl exhibit clear anisotropy. Additionally, these spectra were dependent on the observed polarization. Specifically, the band shape and relative intensity of R-lines varied under different crystallographic orientations. Furthermore, their intensities attained local maximum or minimum values when the crystallographic orientation aligned with the polarization direction of the scattered light. When combined with polarized Raman spectroscopy, it was confirmed that the intensities achieved local maximum or minimum values under parallel polarization configurations when the sample's polarization direction was parallel to the crystallographic orientation. Therefore, photoluminescence spectroscopy emerges as a rapid, precise, and nondestructive method for identifying the crystallographic orientation of gemstones and materials. Upon comparing the photoluminescence spectra and their corresponding polarization degrees of chrysoberyl and ruby, it became apparent that chrysoberyl, due to its lower symmetry and multisite structure encompassing Cr-bearing octahedra, displayed more pronounced anisotropy in its spectrum along a specific polarization direction (E perpendicular to c) compared with corundum. Moreover, chrysoberyl exhibited anisotropy in a greater number of directions than corundum.

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To characterize the trace-element characteristics of chrysoberyl, we studied twenty-six chrysoberyl samples from various localities by using laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS), photoluminescence (PL), and ultraviolet–visible–near-infrared (UV–Vis–NIR) spectroscopy. Chemical analysis has confirmed the existence of trace elements, including Fe, Ti, Ga, Sn, B, Cr, and V. The phenomenon of ionic isomorphic substitution frequently occurs at lattice sites within chrysoberyl. Notably, the isomorphic substitution of Al3+ in octahedral sites is significant, with the primary substituting elements being Fe, Ti, Cr, V, Ga, and Sn. The PL spectra of chrysoberyl samples exhibit sharp peaks at 678 and 680 nm, which are attributed to Cr3+, even in samples in which the Cr concentration is below the detection limit of LA-ICP-MS. This demonstrates the high-sensitivity feature of PL spectroscopy. The UV–Vis–NIR spectra of chrysoberyl samples consistently exhibit a band at 440 nm, and strong double narrow bands near 367 nm and 375 nm are observed. These spectral features are associated with Fe3+ chromophores—specifically, Fe3+-Fe3+ pairs or clusters and Fe3+ ions, respectively. By combining LA–ICP–MS analysis and PL mapping on a sample exhibiting color zoning, it has been found that the darker sections contain a higher concentration of Cr compared to the lighter sections, while the concentrations of other elements remain largely consistent. In other words, subtle variations in Cr concentration may be the underlying cause of color zoning in chrysoberyl.

Tengchong,an ancient border town located in southwest China,has more than 500 years of history in the trading and processing of jadeite.It is an important distribution center for jadeite and the birthplace of China's jadeite culture.Tengchong has three key advanta-ges:location,culture and history,and is able to integrate local culture to form the unique style of"Yunnan Jade Carving".This article combines physical objects with related results of previous studies,based on the different usage and functions of jadeite jewelry and products in Tengchong,in order to analyze and summarize their classification and application.The four aspects of pattern,material,colour and technique are also been analyzed,as well as the linguistic features of jadeite jewelry and products in Tengchong,with the hope of providing ideas and references for the creation of modern jadeite jewelry.

The archaeological amber artefacts undergone inescapable various degrees of weathering (typical irreversible oxidation) would change of the appearance characteristics and internal compositions of amber, further resulting in alternations to the peak shape/position or signal noises in infrared spectra, which brings challenges in origin traceability of archaeological amber. This research firstly reported a reference database of infrared fingerprint signatures of more than 113 pieces of different degrees of geological oxidised amber from Burma, Baltic region, and Fushun (a city in China) to facilitate validation and further comparison with archaeological amber artefacts. Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were applied to discriminate infrared spectra data for dimensionality reduction, classification, and prediction. In this research, four cherished pieces of archaeological amber artefacts (No.1-No.4) excavated from the Haihun Marquis' Tomb of the Western Han Dynasty were investigated as a case study to source the archaeological amber. The external and internal features of them were observed using an optical microscopy. A non-destructive analysis (attenuated total reflection Flourier transformed infrared spectroscopy [ATR-FTIR]) was performed on the archaeological amber artefacts (No.1-No.4), and different degrees of geological oxidised amber reference samples. Results from the infrared spectrum of archaeological amber artefact No.2 revealed peaks at 1226, 1149, 1035, and 974 cm-1, which predominantly existed in the most Burmese amber. Archaeological amber artefacts (No.3 and No.4) displayed obvious oxidation characteristics (dark red colour, serious cracks), the FTIR peaks of which at 1050, 921, 553 and 476 cm-1 converged with that of the Burmese oxidised amber. However, the infrared spectrum of No.1 did not match well with the FITR spectra characteristics of Baltic, Burmese and Fushun amber. PCA was further applied to reduce the dimension of spectra data, and the 15 principal component scores with high contribution were evaluated in LDA to obtain accurate classification results and prediction results. The prediction results indicated that four archaeological amber artefacts excavated from Haihun Marquis' Tomb were all from Burma based on the current existing detection and analysis techniques.The archaeological amber artefacts witnessed the cultural exchange and mutual interaction on the Silk Road, and Burmese amber materials were delivered to China during the period of the Western Han Dynasty by road or via the Maritime Silk Road.

In recent decades, blue and fancy-colour sapphires have been gathered from secondary deposits derived from Tertiary basalts in the Muling area of north-eastern China. In this article, zircon inclusions in the blue sapphires were studied to characterise their morphology and structure, as well as to obtain the age of the host sapphires. The zircon inclusions in the studied samples were euhedral and transparent, and their dominant morphology was similar to that of typical zircon inclusions in sapphires associated with alkali basalts. Raman spectroscopy of the zircons showed only slight radiation damage, and cathodoluminescence images revealed two distinctive zoning patterns (in their cores and rims). LA-ICP-MS analyses of the zircon rims showed typical magmatic Th/U ratios. In situ U-Pb dating of the zircon rims yielded ages of 9 to 8 Ma-which is the inferred upper limit of the formation age of the host sapphires-while cores had much older ages that exceeded 110 Ma (i.e. an inherited age component). The 9-8 Ma sapphire age coincides with Late Miocene basaltic eruptions in the Dunhua-Mishan graben. Age dating of zircon inclusions in the Muling sapphires helps elucidate their geological origin and provides useful information for the provenance determination of gem corundum.

Throughout the history of humanity, gemstones had always been accompanying human beings, and precious stones with beauty and significant value had constantly emerged with the wonderful heritage among ancient civilizations. Previous research on the culture of jade, especially the culture of jade in ancient China, were mostly carried out to explore the relationship between jade and spiritual beliefs, moral concepts, and status symbols from aspects of shape, decoration, texture, and function of jade. But color, as the most distinct feature of gemstones, is less often mentioned on this subject. This article sheds light on the color of gemstones which come from nature, specifically turquoise blue, and lapis lazuli blue, from three of the most influential civilizations: ancient China, ancient Egypt, and Mesopotamia. Our research traces the relationship between humans and gemstones from the aspects of color cognition, cultural relics, gemstones resources and material flow. The purpose of this study is to provide a reference for promoting research on the exchange, mutual learning, and integrated development of the eastern and western cultures encoded in the interaction history of human and gemstones. Turquoise and lapis lazuli once played an important role in human civilization. The relationship between humanity, turquoise and lapis lazuli is essentially able to reflect and reveal human thinking and exploration between themselves and nature. There is no color without material, and materials construct the life of people. In the development of the above three ancient civilizations, turquoise and lapis lazuli are visual representations of social identity and human worship for nature. Moreover, the color, derived from turquoise and lapis lazuli, constantly influences and constructs human daily life in various material forms that collectively constitute the scene of coexistence, diversity, and interaction of multi-regional cultures.

Megacrysts hosted by mantle-derived volcanic rocks provide valuable information on the chemical evolution and ascending history of the parental magmatic systems. However, the origin of the megacrysts has still been far from consensus. Here, we present systematic major-and trace-element data of a variety of gem-quality megacrysts in the Cenozoic basalts from Muling area, northeastern China, with the aim of investigating the origin and for-mational conditions of these megacrysts. The studied megacrysts are composed of clinopyroxene, garnet and orthopyroxene. All megacrysts are optically and compositionally homogeneous. Clinopyroxene megacrysts, with Mg# of 85.3-87.5, contain Al2O3 of 6.64-8.07 wt%, thus can be ascribed as Al-augites. Garnet megacrysts are rich in pyrope component with Mg# of 74.0-76.0 and contain low Cr2O3 less than 0.05 wt%. All orthopyroxene megacrysts are enstatite in composition. According to the color, they can be further divided into two groups (Group 1: greenish brown; Group 2: dark brown) which are apparently different in chemical composition. Group 2 orthopyroxenes have lower Mg# (85.1-86.3) and Cr2O3 (0.09-0.18 wt%) and higher Al2O3 (6.78-7.71 wt%) and TiO2 (0.20-0.24 wt%), while Group 1 orthopyroxenes are characterized by higher Mg# (89.2-89.8) and Cr2O3 (0.55-0.66 wt%) and lower Al2O3 (5.13-5.93 wt%) and TiO2 (0.11-0.15 wt%). Clinopyroxene, garnet and Group 2 orthopyroxene megacrysts can be easily distinguished with equivalent phases in accompanied peridotite xenoliths or peridotite xenoliths in other locations through eastern China by their major-element compositions. They show good correlations between Mg# and major-oxide contents (such as Al2O3 and TiO2), indicating their derivation from melts which had undergone variable extent of fractional crystallization. Mg# and trace-element compositions of their equilibrium melts are incomparable with those of host basalts. We infer clinopyroxene, garnet and Group 2 orthopyroxene megacrysts from Muling are most likely produced by fractional crystallization of basaltic melts that formed earlier than host basalts. Pressure estimations suggest clinopyroxene and garnet megacrysts from Muling were formed at 2.0-2.5 GPa, corresponding to a depth of 66-80 km, near the boundary between lithosphere and asthenosphere based on local lithosphere thickness. Compared with orthopyroxenes in accompanied peridotites, Group 1 orthopyroxene megacrysts have slightly lower Mg# and higher CaO and Al2O3, similar with those produced by basaltic melts-peridotite interaction experiments in which orthopyroxene precipitated with the expense of olivine and clinopyroxene. A revised model (modified from Liu and Ying (2019): Liu, Y.D., Ying, J.F., 2019. Origin of clinopyroxene megacrysts in volcanic rocks from the North China Craton: a comparison study with megacrysts worldwide. International Geology Review 62, 1845-1861.) has been proposed to decipher the formation of variable megacrysts from Muling.

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.

辽代契丹族在其两百多年历史之中创造并留下了丰富的草原文化遗产.金属工艺尤为独树一帜,其纹样完美地体现了不同文化之间的交流.辽契丹与邻国北宋继承了广袤的唐朝版图,契丹这个季节性游牧民族进一步融入了农耕文明,他们在一定程度上继承了唐朝文化,同时也演化出自己的民族特色.来自犹太教的大卫之星纹样,具体起源时间地点仍有争议,但从出现的时空推测,可能在唐朝,或之前经波斯进入古中国.契丹族接受并使用了这来自异域的工艺品,显示出对唐朝文化的继承和对外来文化的包容.来自印度的摩竭纹样通过佛教传入古中国,在唐朝兴起后被契丹族吸收,在辽代进一步融合演变,形成了独特的摩竭纹样风格.这些足以还原一幅契丹族文化继承、文化交流、文化包容与融合的画卷.

Aquamarine and heliodor are colored by Fe ions, an important coloring agent for beryl. Blue to yellow gem beryl was studied by quantitative spectroscopy and trace-element analytical techniques to explore color characteristics and chromophores. Blue color was caused by a 600 nm absorption, while yellow color was attributed to an absorption edge in the violet-blue region. Color ranged from blue to green to yellow due to different proportions of Fe ions with various valences and occupancies. Mn content was positively related to Fe, but abundant Mn ions showed no impact on color (unlike Mn in morganite and red beryl). The arrangement of alkali ions and water in channel and the charge compensation mechanism of beryl are discussed. Alkali ions (mainly Na and Cs) and water were localized in the peanut-shaped channels, and all alkali elements (Li, Na, K, Rb, and Cs) were relevant. Though alkali ions and water interacted with transition metal Fe and Mn ions, their influence on blue to yellow color was indirect and rather weak.

Emeralds were discovered in Malipo County in southwestern China more than 30 years ago. Malipo emeralds are still being extracted and are expected to be available over the next decade. This study provides a full set of data through standard gemological properties, inclusion scenes, color characteristics, and advanced spectroscopic and chemical analyses including Raman, XRD, micro UV-Vis-NIR, EPR, and LA-ICP-MS. Multiphase inclusions in Malipo emerald are distinct with various shapes and occasionally a colorless transparent crystal. Abundant vanadium substitutes for aluminum in the octahedral site and serves as the predominant coloring agent, leading to a yellowish green color. Among significant known deposits, Malipo emerald has a unique chemical composition in its combination of high V, low Cr, and moderate Fe, as well as high Li and Cs concentrations.

Color-change diaspore, known commercially as Zultanite, is sought by designers and consumers for its special optical characteristics, namely its color and color change. Understanding the color origin of gem-grade diaspore could provide a scientific basis to guide its gemological testing, cutting, and valuation. This study uses ultraviolet-visible (UV-Vis) spectra and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to examine the color origin of color-change diaspore and to compare it with corundum. As Raman spectra vibration intensities are closely related to crystal direction for diaspore, crystal orientation was determined through Raman spectroscopy. The color correlation between color-change diaspore and corundum confirmed the identity of each chromophore. In addition, the effectiveness of different chromophores such as Cr3+, Fe2+, Fe2+-Ti4+ pairs, and V3+ between gem-quality diaspore and corundum is compared quantitatively.

The standard of Turquoise Gradingis based on the collection of big data.Analysis of total 51 955turquoise samples has been finished, and turquoise samples have been classified according to colour (hue, saturation, brightness) and surface characteristics.This papers interpret the standard of Turquoise Gradingin three aspects:The standard developing process, grading requirements and grading contents.Turquoise Gradingis completed by naked-eye observation.The grading content includes colour, texture, surface cleanliness, luster, transparency and special patterns.HSB colour grading system is used for colour grading to standardize the classification of hue, brightness, saturation and uneven colour.Density test is used for texture grading.The grading standard has passed through the collection of opinions of the industry as well as the laboratory trial.It proves that the process of turquoise grading is easy to operate.

LA-ICP-MS was used to calibrate 26 turquoise samples with relatively clean and uniform color on each surface. We selected 9 points on each sample to test the homogeneity of their chemical composition. The results showed that the average error coefficients of Al, P, K, Cu, Fe, V, Cr and Zn in turquoise samples are below 5. 4%, while the average error coefficients of CaO and SiO2 are 34. 8% and 16. 2% respectively, suggesting that the elements of Si and Ca in turquoise were heterogeneity. The turquoise working curve can be established by the energy dispersive X-ray fluorescence spectrometer (EDXRF). We used 21 samples as the standard sample for reference and 5 as unknown samples to determine the composition of turquoise. Results showed that the correlation coefficients of Al, P and Cu of the main element are between 92. 3% and 94. 3%, with an average relative error of 4. 6%similar to 9. 7%. The correlation coefficients of Fe, Cr, Zn micro-elements are more than 0. 990, while the correlation coefficients of both K and V elements are 0. 939 and 0. 972. And the average relative error of those five micro-elements ranges from 7. 2% to 13. 9%. However, the correlation coefficients of Si and Ca are 0. 958 and 0. 866, the average relative error of which is 348% and 27. 8% in the five unknown turquoise samples. The high average relative errors of Si and Ca may be influenced by the low content and the heterogeneity of Si and Ca in turquoise, also related to the detection limit of this instrument method. The repeatability test showed that the relative standard deviations (RSDs) of Al, P, Cu, Fe, Zn elements are within 1%, suggesting that the accuracy of the test results is respectively high. While the RSDs of V, Cr, K, Ca, Si elements range from 1. 34% to 10. 17%. The study provides a new idea and method for determining the quantify of the elements of Al, P, Cu, Fe, Cr, Zn and V in turquoise quickly, accurately and losslessly, which can be applied to test and identify turquoise in laboratory.

采用宝石显微镜、偏光显微镜、扫描电子显微镜、X射线粉末衍射仪、傅里叶变换红外光谱仪、拉曼光谱仪等测试方法对近期湖北市场出现的一种仿绿松石材料进行了常规宝石学、矿物学、谱学特征研究.结果表明,该类仿绿松石材料的主要成分为重晶石粉末,样品相对密度为2.83~3.08,隐晶质,不规则断口,用小刀刻划可产生划痕,与盐酸不反应,该仿绿松石材料与天然绿松石的外观相似,但成分结构差异较大.结合扫描电子显微镜、X射线粉末衍射与红外光谱、拉曼光谱测试结果,仿绿松石样品可能为重晶石粉末与有机物固化而成,利用红外光谱与拉曼光谱测试技术能快速有效的无损鉴别出天然绿松石与该仿制品.

Recently, there is a batch of colorless faceted gem-quality natrolite appear in the international jewelry market. In order to provide some information that can help us to distinguish them from the imitations. The infrared spectrometer and Raman spectrometer were employed to study the characteristics of the vibrational spectrum of three natrolite samples in this article. The typical infrared spectra shows that: the absorption region 4000~1200 cm(-1) is induced by stretching vibration of the hydroxyl group, the strong absorption peaks range from 1200~600 cm(-1) are relative with the anti-symmetry and symmetry stretching vibration of tetrahedral T-O bonds (T=Si or Al). The Raman spectra scattering peaks are located in the range of 300~600 and 700~1200 cm(-1). The low intensity Raman scattering spectrum in the range of 300~360 cm(-1) corresponds to the vibration of the water molecules in the crystal. The medium intensity Raman scattering spectrum is assigned to the deformation of SiO4 tetrahedra. The Raman spectra scattering peak at 726 cm(-1) is assigned to the stretching vibration of Al-O; The Si-O stretching vibration displays the Raman spectra scattering peaks at 974, 1038 and 1084 cm(-1).

目前,钻石行业顶级鉴定机构每天的检测量非常大,同时,国际检测机构对高质量宝石级合成钻石的报道成为行业的高敏感话题.本文旨在保障消费者的信心、行业的稳定以及长期发展,响应行业目前热点中的热点——快捷并准确地检测市场上的钻石是国际钻石行业及检测机构迫在眉睫的大事.笔者以2014年春天在上海钻石交易所(SDE)运用美国宝石学院(GIA)推出的快捷检测合成钻石设备——DiamondCheckTM的测试亲历,通过查阅信息资料、咨询业内人士等方法,研究了合成钻石的市场和快捷检测合成钻石设备的现状,进一步介绍了国际顶级鉴定机构几乎同时推出的三项设备:HRD Antwerp(比利时钻石高层议会)的Al-pha Diamond Analyzer(阿尔法钻石分析仪)、GIA的DiamondCheckTM以及De Beers(戴比尔斯)的Automated Melee Screening Device(自动小钻筛选器).最终明确表明“合成钻石百分百可检测”的行业信心.