Results 61 to 70 of about 354 (163)

Spectroscopic Characteristics of Treated‐Color Natural Diamonds

Journal of Spectroscopy, Volume 2018, Issue 1, 2018., 2018
With the increasing availability of treated‐color diamonds on the market, their characterization is becoming more and more critical to the jewelry testers and customers. In this investigation, ten color diamonds treated by irradiation (4 pieces), HPHT (3 pieces), and multiprocess (3 pieces) were examined by spectroscopic methods.
Meili Wang, Guanghai Shi, Joe C. C. Yuan, Wen Han, Qing Bai, Vincenza Crupi   +5 more
wiley   +1 more source

The Pace di Siena and its Gems

Journal of Raman Spectroscopy, Volume 56, Issue 11, Page 1254-1278, November 2025.
For the first time, the gems of the Pace di Siena, a rare en ronde bosse enamel preserved in Arezzo (Italy), have been analyzed using a transdisciplinary approach. The combination of gemmology and Raman spectroscopy has led to the identification of blue sapphires and pink spinels, contradicting previous historical classifications.
Stefania Martiniello, Simi Maria Emilia Mangani, Stefano Legnaioli, Massimo Chiari, Vincenzo Palleschi, Aaron Palke, Simona Raneri   +6 more
wiley   +1 more source

Color Dependence on Thickness in Topaz Crystal from Brazil

Advances in Condensed Matter Physics, Volume 2012, Issue 1, 2012., 2012
It is well known that crystals of topaz from the Eastern Brazilian Pegmatite Province may turn blue by the irradiation with 60Co gamma rays followed by heat treatment. Also, it is known that the sensation of color changes with the thickness of these crystals. The dependence of the color, given by 1931 CIE chromaticity coordinates, with the thickness of
Waldemar Bonventi Jr, Sadao Isotani, Antonio Roberto Pereira Albuquerque, Mohindar S. Seehra   +3 more
wiley   +1 more source

Jewelry and ornamental concretions with fossils of the Republic of Kabardino-Balkaria. Mineral composition, gemological characteristics

Известия высших учебных заведений: Геология и разведка, 2023
Background. Along with ammonites and septaries, concretions with fossils are increasingly being used as jewelry and ornamental materials in Russia. Such concretions are characterized by a wide range of sizes, as well as high decorative and technological ...
D. A. Petrochenkov, E. Yu. Baraboshkin
doaj   +1 more source

Material Profiling of Mesopotamian Cylinder Seals by Raman Spectroscopy

Journal of Raman Spectroscopy, Volume 56, Issue 3, Page 228-242, March 2025.
Mesopotamian cylinder seals (fourth ‐ first millennium bce) from the collection of Museum für Kunst und Gewerbe, Hamburg were non‐destructively studied by Raman spectroscopy were non‐destructively studied by Raman spectroscopy. The Raman spectral analysis identified the mineral constituents and quantitatively determined the chemical compositions of the
Stylianos Aspiotis, Albert Dietz, Zsombor Földi, Frank Hildebrandt, Jochen Schlüter, Boriana Mihailova   +5 more
wiley   +1 more source

A Machine Learning Approach to Single Garnet Geothermometry and Application to Tracing the Fingerprint of Superdeep Diamonds

Geochemistry, Geophysics, Geosystems, Volume 26, Issue 3, March 2025.
Abstract Estimating the equilibration temperatures of mantle‐derived garnets is crucial for assessing the diamond potential of kimberlites. Traditional garnet geothermometers require co‐existing mineral data or costly trace element analysis, limiting their practical use.
Qiwei Zhang, Matthew F. Hardman, Thomas Stachel, Ingrid Chinn, Michael Seller, Bruce Kjarsgaard, D. Graham Pearson   +6 more
wiley   +1 more source

Gemological and Spectral Characteristics of Andradite Garnets with Usambara Effect from Yuanjiang in Yunnan Province

Crystals
Yuanjiang County is one of the most important gem-producing areas in China. The authors of this study discovered and collected gem-quality andradite Garnsts in the epidote amphibolite from the periphery of the ruby deposit in Shaku Village, Yuanjiang ...
Liu-Run-Xuan Chen, Yi-Min Tian, Shi-Tao Zhang, Zhi Qu, Hong-Tao Shen, Xiao-Qi Yang, Yun-Ke Zheng   +6 more
doaj   +1 more source

Gemological Characteristics and Chemical Composition of a New Type of Black Jadeite and Three Imitations

Crystals, 2022
Because of the increasing price of jadeite, many fake species have appeared on the market. We recognized three pieces of fake black jadeite that had been placed among real black jadeite.
Beiqi Zheng, Ke Li, Yuyang Zhang
doaj   +1 more source

ND70 Series Basaltic Glass Reference Materials for Volatile Element (H2O, CO2, S, Cl, F) Measurement and the C Ionisation Efficiency Suppression Effect of Water in Silicate Glasses in SIMS

Geostandards and Geoanalytical Research, Volume 48, Issue 3, Page 637-660, September 2024.
Key Points New set of widely available reference materials, for in situ measurement of volatile elements (H2O, CO2, S, Cl, F) in silicate glass of basaltic composition. Characterised using ERDA, NRA, EA, FTIR and EPMA, and SIMS on four different ion probes. SIMS CO2 measurement results are significantly influenced by the H2O content of the glass.
Yves Moussallam, William Henry Towbin, Terry Plank, Hélène Bureau, Hicham Khodja, Yunbin Guan, Chi Ma, Michael B. Baker, Edward M. Stolper, Fabian U. Naab, Brian D. Monteleone, Glenn A. Gaetani, Kenji Shimizu, Takayuki Ushikubo, Hyun Joo Lee, Shuo Ding, Sarah Shi, Estelle F. Rose‐Koga   +17 more
wiley   +1 more source

Mechanical Impact of Heterogeneously Distributed H2O on Quartz Deformation

Journal of Geophysical Research: Solid Earth, Volume 129, Issue 8, August 2024.
Abstract In order to identify relations between mechanical behavior, deformation mechanisms, microstructural properties, and H2O distribution, Tana‐quartzite samples with added H2O ranging from 0 to 0.5 wt.% were deformed by axial shortening at constant displacement rates, at 900°C and 1 GPa, reaching up to ∼30% bulk strain.
Petar Pongrac, Petr Jeřábek, Holger Stünitz, Hugues Raimbourg, Martin Racek, Michael C. Jollands, Nils Gies, Mona Lueder, Ondrej Lexa, Lucille Nègre   +9 more
wiley   +1 more source