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A woman sits in front of a computer screen with the DiamondView to her right.
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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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Single-crystal CVD diamond
New Technologies and Techniques

Abstracts of speaker presentations from the “New Technologies and Techniques” session of GIA’s 2018 International Gemological Symposium.

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Drilled natural pearls examined in this study.
Saltwater Pearls from the Pre- to Early Columbian Era: A Gemological and Radiocarbon Dating Study

Examines 85 saltwater natural pearls, reportedly harvested from the Caribbean islands off the coast of Venezuela during the early 16th century, to determine their age.

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A blue synthetic star sapphire from past production of Wiede’s Carbidwerk
Synthetic Star Sapphires and Rubies Produced by Wiede’s Carbidwerk, Freyung, Germany

Details the process used by Wiede’s Carbidwerk to produce star synthetic corundum from the mid-1950s through the 1970s.

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Samples of by-product synthetic zincite
Characteristics of Gem-Quality By-Product Synthetic Zincite

Investigates the properties of synthetic zincite produced by industrial kilns in Poland.

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CVD overgrowth on natural diamond
A Synthetic Diamond Overgrowth on a Natural Diamond

Analysis of a diamond graded Fancy blue revealed a CVD synthetic overgrowth on natural diamond.

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10.08 ct HPHT synthetic diamond with color equivalent to Fancy Deep blue
Blue HPHT Synthetic Diamond Over 10 Carats

Results from GIA’s recent testing of a 10.08 ct blue HPHT synthetic diamond, the largest HPHT synthetic recorded to date.

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Richard Nacken in 1907
Synthetic Emeralds Grown by Richard Nacken in the Mid-1920s: Properties, Growth Technique, and Historical Account

Describes the chemical, morphological, and microscopic properties of the first gem-quality synthetic emeralds ever produced, offering a historical perspective on their development.

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Near-colorless and Fancy Vivid purplish pink CVD synthetic diamonds
Observations on CVD-Grown Synthetic Diamonds: A Review

Explores statistical data and defining characteristics of gem-quality CVD synthetic diamonds examined by GIA since 2003.

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2.51 and 3.23 ct CVD synthetic diamonds
Two Large CVD-Grown Synthetic Diamonds Tested by GIA

Two near-colorless rounds, weighing 3.23 and 2.51 ct, were the largest CVD-grown synthetic diamonds GIA has examined.

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