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Diamond

Diamonds are among nature’s most precious and beautiful creations.

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Color

Colorless diamonds are scarce—most diamonds have tints of yellow or brown.

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4Cs

Factors used to describe diamonds: Clarity, Color, Cut, Carat Weight

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Rarity

The rarity of one or more of the 4Cs can affect value.

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Octahedron

The crystal shape of a gem diamond is often the octahedron.

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Trigons

Trigons—little triangular depressions—occur only on octahedral faces.

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Growth marks

Diamond’s growth marks help experts separate diamonds from simulants.

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Tools

Research

A large piece of rough, left, with a portion cut out of it, and six cut and polished diamonds produced from the cut out piece of rough.
Article
Chipping Away at 1,109 ct Lesedi La Rona

Graff reveals the first polished diamonds produced from the Lesedi La Rona, one of the largest pieces of rough ever mined. Plus, other market news.

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A rectangle-shaped gold box, decorated with filigree, granulation and gems.
Article
Metalwork Takes a Bow: Techniques that Enhance Gemstone Jewelry

This collection of jewelry images illustrates how metalwork techniques showcase gemstone and jewelry designs.

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Three loops of diamond ribbons form a bow around a ruby framed by more diamonds.
Article
National Retail Federation Predicts a Cheery Holiday

The building blocks are in place for a strong 2018 U.S. holiday season. Plus, diamond market updates and upcoming auctions.

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Crowds of people on the trade show floor.
Article
Typhoon, Trade Wars and Currency Lows Dampen Hong Kong Shows

Business at the September Hong Kong Gem and Jewellery Shows was spotty, despite a strong world economy. Buyers left early to avoid Typhoon Mangkhut.

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Walstromite inclusion with fan-shaped black fractures.
D-Color Natural IIa Diamond with Walstromite Inclusion

A diamond is proven to have a superdeep origin through an inclusion of CaSiO3-walstromite.

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

Summarizes data collected on more than 15,000 natural blue/gray/violet diamonds examined by GIA during the last decade and examines the mechanisms that produce this color 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

Characterizes 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-Color Blue, Gray, and Violet Diamonds: Allure of the Deep

Summarizes data collected on more than 15,000 natural blue/gray/violet diamonds examined by GIA during the last decade and examines the mechanisms that produce this color range.

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A pile of rough diamonds of various colors.
Article
Robust Demand Brings Increased Rough Diamond Sales

Demand for diamonds has been good so far this year. Rough sales have increased and large diamonds are being mined. Plus: Online sales tax changes.

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A large blue pear shaped diamond hangs from a colorless and pink diamond.
Article
Rockefeller and Fancy Blues Highlight Spring 2018 Auctions

Rockefeller jewels and fancy blue diamonds are the stars of the spring 2018 auction season.

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