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A large yellow cushion cut diamond pendant is partially framed with marquis cut diamonds and hangs from a necklace of mixed cut diamonds.
Article
Yellow Gemstones: Can You Identify Them?

Don’t judge a yellow gem by its colour alone. A variety of gemstones also come in shades of yellow, from diamonds to citrine to garnets.

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A row of various shaped cut and polished pink diamonds.
Article
Why are Pink Diamonds Pink? GIA Researchers Dive Deep into their Crystal Structure

GIA researchers analysed more than 90,000 natural pink diamonds to better understand how these rare and beautiful diamonds formed and got their colour.

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CVD, HPHT and Natural Diamonds
Article
Is There a Difference Between Natural and Laboratory-Grown Diamonds?

Learn about the differences – and similarities – between natural and laboratory-grown diamonds, and how GIA’s researchers and grading laboratories can tell the difference

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A heart-shaped piece of pink drusy hangs from a gold chain.
Article
Dreamy Drusy: Minute Crystals Shimmer in Dramatic Designs

Drusy jewellery has surged in popularity in recent years. Celebrities wear it on the red carpet and designers clamour for it at gem shows.

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Looking down the crystal axis of a back-lit 58.83 ct trapiche emerald
Article
Emerald: The Superstar of Trapiche Gemstones

Trapiche emeralds, which display a distinct six-spoke wheel pattern, set the standard as some of the finest and most spectacular crystals ever unearthed.

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Suite containing over 36 carats of Yogo sapphire
Gemmological Characterisation of Sapphires from Yogo Gulch, Montana

A look at the mining and distinguishing characteristics of this naturally vibrant blue sapphire.

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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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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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Rough CLIPPIR diamonds
The Very Deep Origin of the World’s Biggest Diamonds

Explores an exceptional family of diamonds, referred to as “CLIPPIR” (Cullinan-like, Large, Inclusion-Poor, Pure, Irregular and Resorbed), that formed in a super-deep environment.

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Colombian independent miners
Colombian Emerald Industry: Winds of Change

A first-hand look at Colombia’s emerald mines and the cutting and trading industry in Bogotá.

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