Results 31 to 40 of about 949 (188)
Diffusion of Hydroxylated Si Vacancies in Olivine, and Its Relevance to Si Diffusion
Geochemistry, Geophysics, Geosystems, Volume 24, Issue 5, May 2023., 2023 Abstract The diffusion coefficient associated with the 3,612 cm−1 infrared absorbance band in H‐bearing olivine, attributed to a defect involving a vacant Si site balanced by four H+ (i.e., ), was determined in H in‐diffusion experiments at 1200°C–1400°C and 1.5–3.0 GPa in piston‐cylinder and multi‐anvil apparatuses.
Michael C. Jollands
wiley +1 more source
Mineralogical and gemological characteristics of Kaman (Kırşehir-Türkiye) fluorites
Gümüşhane Üniversitesi Fen Bilimleri Enstitüsü Dergisi, 2022 Fluorites are found in the region between Hamit, Karakütük, Bayındır and Yeniyapan villages of the Kaman District (Kırşehir-Türkiye). Fluorites are located in altered levels due to faults in quartz syenites containing gray-pink colored K-feldspar, plagioclase and quartz, amphibole and biotite type mafic minerals in the Upper Cretaceous aged.
İlkay KAYDU AKBUDAK +2 more
openaire +1 more source
Spectroscopic Study on the Species and Color Differences of Gem‐Quality Red Garnets from Malawi
Journal of Spectroscopy, Volume 2022, Issue 1, 2022., 2022 To reveal the species of gem‐grade red garnets with similar colors, especially the mechanisms underlying their subtle color differences, a series of tests, including conventional gemological tests, X‐ray diffraction, Fourier‐transform infrared spectroscopy, ultraviolet‐visible spectroscopy, and X‐ray photoelectron spectroscopy, were performed on gem ...
Ming Li, K. S. V. Krishna Rao
wiley +1 more source
Spectroscopic Characteristics and Color Origin of Red Tourmaline from Brazil
Journal of Spectroscopy, Volume 2022, Issue 1, 2022., 2022 In the present paper, I report on the spectroscopic study for tourmaline color origin, performed red samples from Minas Geras State, Brazil, by gemological routine testing, X‐ray diffraction, Fourier transform infrared spectroscopy, ultraviolet‐visible spectroscopy, and X‐ray photoelectron spectroscopy.
Ming Li, Davidson Sajan
wiley +1 more source
Characterization of Blue Tourmaline from Madagascar for Exploring Its Color Origin
Advances in Condensed Matter Physics, Volume 2022, Issue 1, 2022., 2022 In the research, spectroscopic studies of tourmaline for color origin were performed by X‐ray diffraction, Fourier transform infrared spectroscopy, ultraviolet‐visible spectroscopy, and X‐ray photoelectron spectroscopy. The research work emphasized the analysis of transition metal atoms, including their valence state and coordination number, in order ...
Ming Li, Ram N. P. Choudhary
wiley +1 more source
Geochemistry, Geophysics, Geosystems, Volume 22, Issue 12, December 2021., 2021 Abstract Biominerals that accrete shell or skeleton are commonly used as windows to past geochemical environments. Using biominerals as paleoproxies depends on the assumption that biominerals faithfully and predictably record environmental parameters, yet little has been done from a mineralogical perspective to understand how various environmental ...
G. A. Farfan +3 more
wiley +1 more source
Gemological Characteristics of Lvwen Stone and Its Color Genesis
Minerals, 2022 “Lvwen stone” is a yellow-green carbonate jade gemstone. In this study, the gemological characteristics and color genesis of Lvwen stone were investigated using conventional gemological testing methods and analytical techniques, such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–VIS ...
Zhendong Liu +10 more
openaire +1 more source
Journal of Raman Spectroscopy, Volume 52, Issue 1, Page 71-77, January 2021., 2021 Abstract Raman spectroscopy is a convenient, efficient, and non‐destructive technique that could estimate the metamictization degree of zircon, particularly for gem‐class or historical samples. The full width at half maximum value of the ν3(SiO4) band around 1000 cm−1 can classify the structural state of zircon as crystallized (the full width at half ...
Shijia Gao, Gerhard Heide
wiley +1 more source
A Case Study on Distribution of Gemstone in Bela Ophiolite, District Khuzdar, Balochistan [PDF]
, 2022 Bela Ophiolite and suture zone host several types of gemstones in the underlain and overlain rocks such as garnet (demantoid and almandine), quartz, brucite, malachite, chrysocolla, azurite, calcite, natrolite, green chert, jasper, serpentine, agate ...
Ahmad, Jalil +5 more
core +3 more sources
Gemological and Spectroscopic Characteristics of “Jedi” Spinel from Man Sin, Myanmar
Minerals, 2022 The price of spinel has sharply risen in recent years, and its market acceptance is extending. Among the many sources of spinel, Man Sin in Myanmar is the most famous for its bright neon pinkish red to reddish pink color, named “Jedi” spinel commercially.
Longpei Zhao, Geng Li, Liqun Weng
openaire +1 more source