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Husband and wife gaze happily at emerald rough found in a Colombian mine.
Article
Colombian Emerald Industry: Winds of Change

Andy Lucas, GIA’s education manager of field gemmology, researches and documents the mine to market journey of gemstones. Lucas shares the changes he observed in Colombia’s major emerald mining and cutting areas in a presentation he gave at the 2017 JCK Las Vegas show.

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Mining Diamonds in the Canadian Arctic: The Diavik Mine

Located near the Arctic Circle, Diavik is one of the world’s richest diamond deposits and a leader in sustainable mining.

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Two variscite cabochons from central Tajikistan
Variscite from Central Tajikistan: Preliminary Results

A look at the gemmological properties and chemical composition of this light blue to light green to green gem material, which is suitable for cabochon cutting.

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299.35 ct and 112.61 ct diamond rough
Letšeng’s Unique Diamond Proposition

Explores the history, geology and current production of this unique source of large diamonds.

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Article
Field Report: Diamond Mining in Minas Gerais, Brazil

A first-person account of diamond mining in Minas Gerais, Brazil, which has been a source since the early 1700s.

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A notebook, pen, mobile phone with compass app and a digital camera sit on top of a map.
Article
The Stories Behind the Photos: A Gigantic Aquamarine and ‘Gaudy’ Nature

Gemmological photojournalist Robert Weldon shares the stories behind some of his favourite photos.

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Article
GIA's Gübelin Gem Project: Corundum

Ruby and sapphire (usually blue, but also in every other colour) have been the most important coloured gemstones for several thousand years. Originating historically in south-east and central Asia, and more recently in eastern Africa, these coloured varieties of the mineral corundum have been much sought as gems because of their rarity, colour and durability. Gem corundum can display asterism and chatoyancy due to the presence of oriented mineral inclusions, and in some cases, a change of colour when viewed under different light sources.

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Spinel 80909 300x169
Article
GIA's Gübelin Gem Project: Spinel

Found in nearly every colour – most notably red, pink and blue – spinels are popular gemstones because of their abundance, moderate cost and attractiveness.

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Article
GIA's Gübelin Gem Project: Various Gems, Taaffeite - Zoisite

Among the collection assembled by Dr Edward Gübelin are a number of uncommon gemstones from many worldwide localities.

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Article
GIA's Gübelin Gem Project: Various Gems, Sapphirine - Stibiotantalite

Among the collection assembled by Dr Edward Gübelin are a number of uncommon gemstones from many worldwide localities.

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