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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

Stuart Overlin, Brooke Goedert and Kellie Giordano, December 13, 2019

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

Update on Trace-Element Chemical Characteristics of Golden Sheen Sapphire

Makoto Miura, Yusuke Katsurada, and Kazuko Saruwatari, August 9, 2018

An update the gemmological and chemical characteristics of golden sheen sapphires from Kenya.

A black star sapphire with one set of golden rays and another set of silver rays.

Twelve-Rayed Star Sapphire from Thailand

Wim Vertriest and Simon Bruce-Lockhart, August 9, 2018

A black star sapphire produced from eastern Thailand, showing both golden and silver rays, is studied at GIA’s Bangkok lab.

Synthetic ruby overgrowth on natural sapphire seed.

Two Unusual Natural Sapphires with Synthetic Ruby Overgrowth

Tyler Smith and Hollie McBride, January 26, 2018

For the first time, the Carlsbad and New York labs see natural sapphire seeds with synthetic ruby overgrowth.

Pink Sapphire Filled with Bismuth-Based Glass

Ratima Suthiyuth, May 8, 2017

A sapphire with a colour not commonly seen in the lab is found to have a glass filling.

Multi-Elemental Diffused and Melt-Grown Synthetic Sapphire

Ziyin Sun, Jonathan Muyal, and Nicole Ahline, May 8, 2017

GIA examines a multi-elemental diffused and melt-grown synthetic sapphire for the first time.

Negative crystals creating rosette pattern.

Negative Crystals in Sapphires

Victoria Raynaud and Wim Vertriest, May 8, 2017

Sapphires from Baw Mar host multiphase inclusions in appealing patterns.

Multiphase Fluid Inclusions in Blue Sapphires from the Ilmen Mountains, Southern Urals

Elena S. Sorokina, John I. Koivula, Jonathan Muyal, Stefanos Karampelas, Tursun P. Nishanbaev, and Sergey N. Nikandrov, August 3, 2016

Sapphires from Russia’s Ilmen State Reserve may provide an insight into gem-quality corundum from secondary placers.

Ruby and Sapphire from Muling, China

Yimiao Liu and Ren Lu, April 28, 2016

An emerging corundum deposit in north-eastern China is discussed.

Article

Pyrope Garnet and Montana Sapphires Highlight Winter 2015 G&G

Russell Shor, February 1, 2016

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

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