Results 41 to 50 of about 1,737 (200)
Gemological Characteristics of Blue-Violet Cordierite
CrystalsCordierite is a violet-blue gem mineral primarily composed of magnesium aluminum silicate. This study employed three samples of Mg-cordierite and conducted tests on their gemological characteristics, spectroscopic features, and chemical composition using
Wenjie Yan +3 more
doaj +1 more source
Photochromism, UV-Vis, Vibrational and Fluorescence Spectroscopy of Differently Colored Hackmanite
Crystals, 2023 Because of the rich fluorescent color and unique photochromic properties, hackmanite has attracted many mineralogists. In this paper, the basic gemmological characteristics and photochromic and fluorescence mechanisms of four different colors of ...
Chuchu Song +4 more
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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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Crystals, 2023 The Chuncheon nephrite deposit in South Korea is one of the major nephrite deposits in the world, but its origin has been rarely studied. This study explores the mineralogical and geochemical characteristics of the Chuncheon nephrite using a polarizing ...
Nan Li, Feng Bai, Qi Peng, Mengsong Liu
doaj +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
Minerals in Afghanistan : gemstones of Afghanistan [PDF]
, 2007 Afghanistan and gemstones have been inextricably linked for 6500 years and the country remains rich in precious and semiprecious gemstone deposits (Figure 1). Lapis lazuli, mined in the Hindu Kush since the Neolithic Period, was transported along the
Benham, Antony John, McIntosh, Robert
core
3D Imaging of Gems and Minerals by Multiphoton Microscopy
, 2018 Many optical approaches have been used to examine the composition and structure of gemstones, both recently and throughout history. The nonlinear optical behavior of different gemstones has not been investigated, and the higher order terms to the ...
Cromey, Benjamin +2 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
Thermal Temperature Measurements of Plasma Torch by Alexandrite Effect Spectropyrometer
Advances in Optical Technologies, Volume 2010, Issue 1, 2010., 2010 An alexandrite effect spectropyrometer is used to directly measure the thermal temperature of an argon gas plasma jet from a 100 kW DC plasma torch, and the directly measured thermal temperature of the plasma is 11178 ± 382 K. By using the spectral correction function to delete the spectral lines and to correct its underlying spectrum of the relative ...
Peir-Jyh Wang +3 more
wiley +1 more source