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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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Suite containing over 36 carats of Yogo sapphire
Gemological Characterization of Sapphires from Yogo Gulch, Montana

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

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CVD- and HPHT-grown synthetic diamonds.
Features of Synthetic Diamonds

Presents a visual guide to the growth processes and major gemological spectroscopic features of synthetic diamonds.

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Natural blister in the form of a pearlfish.
Natural Blister from Entombment of a Pearlfish Within a Pinctada Maxima Shell

A blister in a P. maxima shell, formed when the mollusk's nacre covered a trapped pearlfish, preserves the fish in stunning detail.

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Cat's-eye demantoid with well-aligned horsetail inclusions.
Cat's-Eye Demantoid and Brown Andradite with Horsetail Inclusions

The examination of two unusual garnets results in identifications issued for the first time in GIA's colored stone report records.

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Recently submitted 3.52 ct. CVD-grown diamond.
Five CVD Synthetic Diamonds Greater Than Three Carats

The GIA lab examines five gem-quality CVD-grown diamonds in sizes that reflect the improving technology of the synthetic gemstone industry.

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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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 Large open mussel shell with pink interior
Article
Freshwater Pearling in Tennessee

Natural pearl identification is one of the critical problems in pearl research. The DNA study of pearly mollusks and oysters facilitates solving this problem. To fulfill this goal, GIA sent a group from both research and education to Tennessee to sample the freshwater mollusks for DNA bar coding. Come with us to Camden, Tennessee, to see how we dive for pearly shells.

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Pearls, shells, and jewelry on table
Article
The Lure of American Freshwater Pearls: Revisiting the Latendresse Family

John Latendresse is known as the father of American cultured pearls. He was also a great natural pearl collector and left his family a remarkable natural pearl collection. The Latendresse family is well recognized in the American pearl industry and has long supported GIA pearl research. Come with us to revisit this family and their pearl collection.

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5.19 ct CVD synthetic diamond
CVD Synthetic Diamond Over 5 Carats Identified by GIA

Results from GIA’s recent testing of a 5.19 ct CVD synthetic diamond, the largest it has examined to date.

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