Results 71 to 80 of about 941 (201)

Authenticity and provenance studies of copper-bearing andesines using Cu isotope ratios and element analysis by fs-LA-MC-ICPMS and ns-LA-ICPMS [PDF]

open access: yes, 2018
Whereas colored andesine/labradorite had been thought unique to the North American continent, red andesine supposedly coming from the Democratic Republic of the Congo (DR Congo), Mongolia, and Tibet has been on the market for the last 10years.
Fontaine, Gisela   +3 more
core  

Mechanical Impact of Heterogeneously Distributed H2O on Quartz Deformation

open access: yesJournal 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   +9 more
wiley   +1 more source

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

open access: yesCrystals, 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

Fingerprinting of ruby and sapphire gemstones through Fourier-transform infrared (FTIR) methodologies [PDF]

open access: yes
Gemstones have significant economic, cultural and artistic value. Advances in the treatment and production of synthetic gemstones create the need for more precise identification methods to distinguish natural stones from their synthetic 10 and treated ...
Bayés-García, Laura   +4 more
core   +1 more source

Gemmological Characteristics of Gemstone Varieties Found in the Pegmatite of Haramosh Area, Gilgit-Baltistan [PDF]

open access: yes, 2020
Haramosh valley is located in eastern side of Gilgitcity (Fig. 1). Geographically it is located between74°44' 17.37 " E and 35° 51 '8.97 " N. The area is asub range of Karakoram in the south-central region ofthe Rakaposhi–Haramosh mountains.
Alam, Muhammad   +5 more
core   +2 more sources

Corroborating the autoptic identification of archeological glyptics in museum collections: The contribution of portable Raman spectroscopy

open access: yesJournal of Raman Spectroscopy, Volume 55, Issue 2, Page 200-215, February 2024.
A collection of Hellenistic–Roman glyptics was investigated in situ at the Regional Archaeological Museum “Paolo Orsi” (Syracuse, Italy), with portable Raman spectroscopy. 85% of the samples was successfully identified, the attribution was corrected for 4% of the gemstones, among which a gold ring with garnet, previously mistaken for carnelian.
Maria Cristina Caggiani   +5 more
wiley   +1 more source

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

open access: yesCrystals
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   +6 more
doaj   +1 more source

Gemological, Mineralogical and Spectral Characteristics of Forsterite from Pitawak Mine, Sar-e-Sang, Badakhshan, Afghanistan

open access: yesCrystals
The Sar-e-Sang lapis lazuli deposit has a mining history exceeding 5000 years, producing the world’s finest lapis lazuli. Recently, gem-quality forsterite has been discovered in the marble containing spinel, dolomite, and phlogopite at the periphery of ...
Dai Zhang   +11 more
doaj   +1 more source

The Gemological Collection of Abraham Gottlob Werner [PDF]

open access: yes, 2021
The gemological collection of Abraham Gottlob Werner contains 1374 sample numbers for 25 different minerals with 38 gemological varieties, including 15 newly added numbers of samples, which were not recorded in the original catalog of 1823. In total, 168
Gao, Shijia
core   +1 more source

Study on the Microstructure and Spectra of Regrown Quartz Crystals from Chinese Jewelry Market

open access: yesCrystals, 2021
Regrown quartz crystals consist of the natural section and the synthetic section grown by hydrothermal technique, which has become popular on the Chinese jewelry market in recent years.
Danyi Zhou   +6 more
doaj   +1 more source

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