Results 51 to 60 of about 1,737 (200)

Color Mechanism Analysis and Origin Comparison of Pink-Purple Sapphires from Vietnam and Madagascar

Crystals
Extensive 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, Pengyu Li, Mingying Wang, Siyi Zhao, Sichun Yang, Guanghai Shi   +5 more
doaj   +1 more source

Gemological and Mineralogical Characteristics of Emerald from Ethiopia

Crystals, 2023
Ethiopia has been gaining attention in recent years as an emerging source of high-quality emerald. Ethiopian emerald samples with different colors ranging from dark green to light green were selected to study the gemological properties, chemical ...
Zixuan Huang, Geng Li, Liqun Weng, Meilun Zhang   +3 more
doaj   +1 more source

Enhanced metrology using preferential orientation of nitrogen-vacancy centers in diamond [PDF]

, 2014
We demonstrate preferential orientation of nitrogen-vacancy (NV) color centers along two of four possible crystallographic axes in diamonds grown by chemical vapor deposition on the {100} face.
Bar-Gill, N., Belthangady, Chinmay N., LeSage, David Anthony, Lukin, Mikhail D., Markham, M., Pham, Linh My, Stacey, A., Twitchen, D. J., Walsworth, Ronald L.   +8 more
core   +1 more source

Study of Garnets in Hellenistic–Roman Jewellery From the Collections of the Archaeological Museum of Thessaloniki, Greece

Journal of Raman Spectroscopy, Volume 56, Issue 11, Page 1235-1253, November 2025.
This study presents the gemological analysis of 25 garnets from Hellenistic and Roman jewellery in the Archaeological Museum of Thessaloniki using mobile Raman spectroscopy and micro‐EDXRF. The garnets are classified into three geochemical clusters, with notable differences in distribution between Thessaloniki and Pydna, suggesting distinct trading ...
Maria Nikopoulou, Stefanos Karampelas, Evangelia Tsangaraki, Lambrini Papadopoulou, Christos Katsifas, Ioannis Nazlis, Annareta Touloumtzidou, Vasilios Melfos, Nikolaos Kantiranis   +8 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

Deciphering the Tanzanian Ruby–Zoisite Enigma: A Confluence of Geochemistry, Microtextures, and Mineralogy

Crystals
The Longido region (Tanzania) hosts a distinct corundum–zoisite paragenesis, renowned for its ornamental value and geological significance as a tracer of Pan-African tectonothermal events.
Ling Yang, Mingyue He, Cui Fei, Hairong Zheng, Xinjie Li   +4 more
doaj   +1 more source

Modeling the polychromism of oxide minerals: The case of alexandrite and cordierite

Journal of Computational Chemistry, Volume 45, Issue 12, Page 834-842, May 5, 2024.
In this work, we tested the embedded cluster approach for the simulation of the polychromism of alexandrite and cordierite by TD‐DFT. The fitted point charge embedding allowed to reproduce both transition energies and anisotropy of absorption spectra at the origin of the polychromism of these minerals. The simulation was in qualitatively good agreement
Raphaël Rullan, Pauline Colinet, Quentin Desdion, Stephan N. Steinmann, Tangui Le Bahers   +4 more
wiley   +1 more source

Comparative Study on Gemological and Mineralogical Characteristics and Coloration Mechanism of Four Color Types of Fluorite

Crystals, 2023
Fluorite has been attracting the attention of gemstone mineralogists because of its rich color and excellent fluorescence properties. This paper studied fluorite with three color types (blue, green, and white) and five blue-purple fluorites with an ...
Yang Liu, Qingfeng Guo, Liangyu Liu, Sixue Zhang, Qingling Li, Libing Liao   +5 more
doaj   +1 more source

An overview of Principal Components Analysis approaches in Raman studies of cultural heritage materials

Journal of Raman Spectroscopy, Volume 55, Issue 2, Page 125-147, February 2024.
The present overview answers the need of evaluating the current state of the art concerning the application of principal components analysis (PCA) to Raman spectroscopy studies of cultural heritage materials. Painting materials, both colouring and binding ones, were considered, together with natural and synthetic glasses, biogenic and mineral ...
Alessia Coccato, Maria Cristina Caggiani
wiley   +1 more source

High-Magnesium Olivines (Fo 90–100): Determination of Fo Content by Raman Spectroscopy

Crystals
Olivine is a dominant constituent of the Earth’s upper mantle, and its forsterite content (Fo = 100 × Mg/(Mg + Fetotal) in molar basis) holds significant implications for indicating petrogenesis.
Tianqi Wang, Mingyue He, Bijie Peng, Jingxuan Wang, Mei Yang, Ning Wang   +5 more
doaj   +1 more source