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A face-up view of a cushion cut diamond with blue color.
Article
Gems & Gemology’s 7 Most Unusual Encounters from 2019

Check out some of the most interesting and unusual diamonds and coloured stones submitted to GIA’s laboratories in 2019.

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A large group of people outside on GIA’s Carlsbad, California  campus.
Article
Guardians of Trust: GIA’s Innovative Research, Instruments and Services

GIA’s services and instruments have grown in importance and impact as new gem treatments and laboratory-grown gems have entered the market.

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CVD- and HPHT-grown synthetic diamonds.
Features of Synthetic Diamonds

Presents a visual guide to the growth processes and major gemmological spectroscopic features of synthetic diamonds.

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Greenish yellow doublets.
Synthetic Sapphire and Synthetic Spinel Doublets

Unusual doublets created from two different synthetics are revealed at the Carlsbad laboratory.

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This specimen was revealed to be a synthetic star sapphire.
Unusual Combination of Inclusions in Synthetic Star Sapphire

A hexagonal boundary, usually found in natural material, is observed in a synthetic star sapphire.

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Eight HPHT faceted synthetic diamonds from AOTC Group
Near-Colourless HPHT Synthetic Diamonds from AOTC Group

Presents the gemmological and spectroscopic properties of a suite of synthetic diamonds grown by AOTC using high pressure and high temperature.

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Sapphire
Article
Sapphires from the Gem Rush Bemainty area, Ambatondrazaka (Madagascar)

The discovery of many fine quality sapphires in this area is opening a new chapter in the conflict between conservation and gem mining in north-eastern Madagascar.

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Fall 2016 Gems & Gemology Cover
Article
Autumn 2016 G&G: CVD Synthetic Diamonds Survey, Reversible Colour Change in Blue Zircon

A summary of the content found in the Autumn 2016 issue of Gems & Gemology.

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Blue Sapphires
Article
An In-Depth Gemmological Study of Blue Sapphires from the Baw Mar Mine (Mogok, Myanmar)

GIA field gemmologists visited the Baw Mar operations in 2013, 2014 and 2015. In this study, we analysed samples collected during two separate expeditions.

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Article
Summer 2015 G&G: Dual-Stars, Photomicrography Guide, Rubies from Tajikistan, New Micro-World Section

G&G Brief presents an overview of the content of the Summer 2015 issue of Gems & Gemology.

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