Results 41 to 50 of about 1,047 (213)
Crystals, 2022 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 by ...
Yi Zhang, Jing-Ran Zhu, Xiao-Yan Yu
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Crystals, 2023 The geographic origin determination of ruby is increasingly important in the gem trade and geological research. Unlike metamorphic-related ruby, the rarer basalt-related ruby has gained significant attention, especially from Thailand, a major producer of
Enqi Li, Bo Xu
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Gemology of Emeralds from Tauá, Brazil
Anuário do Instituto de GeociênciasIn Brazilian territory many occurrences do not have their gemological and optical properties documented or made public. This research aimed to analyze the mineralogical and gemological aspects of emeralds from the city of Tauá (Brazil), utilizing ...
Isaac Gomes de Oliveira +8 more
semanticscholar +1 more source
Journal of Spectroscopy, Volume 2019, Issue 1, 2019., 2019 This paper presents a spectroscopic analysis and solubility study of rosin, copal, and Burmese amber samples to reveal the structural changes that occur during amber formation. The infrared spectra indicate that during the long geological process of amber formation, small resin molecules first crosslinked and slowly oxidized, eventually forming a ...
Feng Bai +3 more
wiley +1 more source
CrystalsThis study measured the infrared spectra of secondary minerals in the oxidation zones of three types of copper ores: dioptase, malachite, and azurite, and assigned the peak positions of OH stretching vibrations and the origins of OH combination ...
Shaokun Wu +5 more
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Spectroscopy and Trace-Element Characteristics of Emeralds from Kamakanga, Zambia
Crystals, 2023 Currently, Zambia is the second largest source of emeralds, after Colombia. In this study, emerald samples from the Zambian Kamakanga deposit were examined by UV-Vis-NIR, Miro-FTIR, Diamond ViewTM, and LA-ICP-MS.
Yi Zhang, Xiaoyan Yu
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CrystalsThe 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 ...
Yingzhao Wang +3 more
semanticscholar +1 more source
Journal of Spectroscopy, Volume 2018, Issue 1, 2018., 2018 In order to better understand the effect of transition metal cations on color of tourmaline, X‐ray photoelectron spectroscopy was used to investigate the species, chemical state, site occupancy, and chemical environment of color‐induced metal cations in colorful tourmaline samples from Minas Gerais State, Brazil.
Ming Li +6 more
wiley +1 more source
Color Mechanism Analysis and Origin Comparison of Pink-Purple Sapphires from Vietnam and Madagascar
CrystalsExtensive research has already been conducted on sapphires, yet there remains a notable absence of methods available to identify the provenance of pink-purple sapphires, particularly those originating from Vietnam and Madagascar. This study examined pink-
Qiurong Guo +5 more
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Raman Spectroscopy of Amphibole Inclusions in Emeralds
Journal of Raman Spectroscopy, Volume 56, Issue 11, Page 1228-1234, November 2025.Emeralds containing elongated amphibole inclusions from Austria, Russia, Zambia and Zimbabwe were investigated with an optical microscope and Raman spectroscopy. The inclusions have various sizes and shapes; curved inclusions are frequently observed in emeralds from Zimbabwe and rarely in those from Zambia.
Stefanos Karampelas +2 more
wiley +1 more source