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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 woman sits in front of a computer screen with the DiamondView to her right.
Article
Inside De Beers’ Lightbox Diamonds

GIA researcher analyzes and confirms that De Beers’ Lightbox diamonds are grown using the chemical vapor deposition process.

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Cushion cut synthetic diamond
Article
Laboratory-Grown Diamonds: Demand Rises, Prices Fall

The proliferation of laboratory-grown diamonds into the market continues to dominate industry news. Plus: Natural Diamonds, Kimberley Process

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A pile of near-colorless HPHT synthetic melee
Article
Diamond Market Forecast: Declining Credit, Soft Prices and Lab-Grown Diamonds

Despite the generally strong year for jewelry retail, the diamond industry continues to face problems with credit, spotty demand and soft prices.

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Natural diamond with CVD synthetic diamond overgrowth
CVD Layer Grown on Natural Diamond

A composite of synthetically grown and natural diamond was recently identified by the Carlsbad laboratory.

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552.7 ct Yellow Diamond from the Diavik Mine
The Largest Diamond Ever Discovered in North America

GIA examines a 552.7 ct diamond from the Diavik mine in Canada.

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A bow brooch with long ribbon tendrils.
Article
Bows in Jewelry: The Finishing Touch in Giving

Bows have been a popular motif and finishing touch in jewelry and fashion from time immemorial, recurring and adapting to reflect the style of the era.

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Diamond from Jericho eclogite and Juina superdeep diamond
Diamonds from the Deep: How Do Diamonds Form in the Deep Earth?

G&G’s newest section explores how diamonds form in the deep earth.

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1.15 ct round brilliant diamond
Chart: Inclusions in Natural, Synthetic, and Treated Diamond

Provides a visual guide to the internal features of natural, synthetic, and treated diamonds.

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Suggested Reading on Diamond Inclusions

Suggested Reading on Diamond Inclusions

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The ring is designed with a wavy strip of black diamonds in the center framed on each side with colorless diamonds set in a ruffled edge The earring are crescent shaped with black diamond on the inside framed by colorless diamonds in a ruffled edge.
Article
GIA Researchers Look Inside Black Diamonds

Black diamonds are striking in jewelry. GIA researchers report on the unique properties used to identify black diamonds and the potential treatments.

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