Natural-Colour Blue, Grey and Violet Diamonds: Allure of the Deep
Sally Eaton-Magaña, Christopher M. Breeding, and James E. Shigley, August 6, 2018
Summarises data collected on more than 15,000 natural blue/grey/violet diamonds examined by GIA during the last decade and examines the mechanisms that produce this colour range.
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Black Diamonds from Marange (Zimbabwe): A Result of Natural Irradiation and Graphite Inclusions
Karen V. Smit, Elina Myagkaya, Stephanie Persaud, and Wuyi Wang, August 6, 2018
Characterises a suite of 40 natural brown to black diamonds from this deposit so that they can be distinguished from suspected treated black diamonds.
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An Early Byzantine Engraved Almandine from the Garibpet Deposit, Telangana State, India: Evidence for Garnet Trade Along the Ancient Maritime Silk Road
H. Albert Gilg, Karl Schmetzer, and Ulrich Schüssler, August 6, 2018
Analyses the chemical composition and inclusion characteristics of this ancient artefact.
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Accurate Reporting of Key Trace Elements in Ruby and Sapphire Using Matrix-Matched Standards
Jennifer Stone-Sundberg, Timothy Thomas, Ziyin Sun, Yunbin Guan, Zachary Cole, Randy Equall, and John L. Emmett, January 26, 2018
Presents a group of corundum standards developed by GIA to improve the accuracy and efficiency of its laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) instruments.
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Real-Time Microradiography of Pearls: A Comparison Between Detectors
Stefanos Karampelas, Abeer Tawfeeq Al-Alawi, and Ali Al-Attawi, January 26, 2018
Compares the image quality provided by real-time microradiographic imaging (RTX) units fitted with two different detectors: an image intensifier (II) and a flat panel detector (FPD).
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Inclusions in Natural, Synthetic and Treated Ruby
Nathan D. Renfro, John I. Koivula, Jonathan Muyal, Shane F. McClure, Kevin Schumacher, and James E. Shigley, January 26, 2018
Provides a visual guide to the internal features of natural, synthetic and treated rubies.
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Akoya Cultured Pearl Farming in Eastern Australia
Laura M. Otter, Oluwatoosin B. A. Agbaje, Le Thi-Thu Huong, Tobias Häger, and Dorrit E. Jacob, January 26, 2018
Characterises the akoya cultured pearls produced on the eastern shoreline of Australia using native Pinctada imbricata fucata molluscs.
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True Colours of “Dalmatian Jasper”
Tomasz Powolny and Magdalena Dumańska-Słowik, November 8, 2017
Discusses the mineralogical composition and provenance of this spotted decorative gemstone.
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Saltwater Pearls from the Pre- to Early Columbian Era: A Gemmological and Radiocarbon Dating Study
Chunhui Zhou, Gregory Hodgins, Todd Lange, Kazuko Saruwatari, Nicholas Sturman, Lore Kiefert, and Klaus Schollenbruch, November 8, 2017
Examines 85 saltwater natural pearls, reportedly harvested from the Caribbean islands off the coast of Venezuela during the early 16th century, to determine their age.
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Photoluminescence Spectra of Emeralds from Colombia, Afghanistan and Zambia
D. Brian Thompson, Christian J. Bayens, Matthew B. Morgan, Taylor J. Myrick, and Nealey E. Sims, November 8, 2017
Compares PL spectroscopy data of 48 emerald samples from three countries to evaluate the usefulness of the technique in geographic origin determination.
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