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Recently discovered and legendary diamonds in the blue/gray/violet color range
Natural-Colour Blue, Grey and Violet Diamonds: Allure of the Deep

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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Fancy Dark brown to Fancy black Marange diamonds
Black Diamonds from Marange (Zimbabwe): A Result of Natural Irradiation and Graphite Inclusions

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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Timeline showing the use of garnets in different eras from 300 BCE to 700 CE
An Early Byzantine Engraved Almandine from the Garibpet Deposit, Telangana State, India: Evidence for Garnet Trade Along the Ancient Maritime Silk Road

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

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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Three cultured pearls, one natural
Real-Time Microradiography of Pearls: A Comparison Between Detectors

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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Micro-Features of Ruby
Inclusions in Natural, Synthetic and Treated Ruby

Provides a visual guide to the internal features of natural, synthetic and treated rubies.

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Bracelet containing akoya cultured pearls from Australia
Akoya Cultured Pearl Farming in Eastern Australia

Characterises the akoya cultured pearls produced on the eastern shoreline of Australia using native Pinctada imbricata fucata molluscs.

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Dalmatian stone samples
True Colours of “Dalmatian Jasper”

Discusses the mineralogical composition and provenance of this spotted decorative gemstone.

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Drilled natural pearls examined in this study.
Saltwater Pearls from the Pre- to Early Columbian Era: A Gemmological and Radiocarbon Dating Study

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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Emerald crystals from Colombia, Afghanistan, and Zambia
Photoluminescence Spectra of Emeralds from Colombia, Afghanistan and Zambia

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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