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Rough and faceted natural-color green diamonds.
Natural-Color Green Diamonds: A Beautiful Conundrum

Characterizes diamonds with exceptionally rare natural green color, based on GIA’s extensive database of samples.

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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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The Wittelsbach Blue

This article describes what is known about the Wittelsbach Blue since it was first reported in 1666, and the gemological information released to date on this diamond.

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Developments in Gemstone Analysis Techniques and Instrumentation During the 2000s

The first decade of the 2000s continued the trend of using more powerful analytical instruments to solve gem identification problems.

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Hydrogen-rich Diamonds
Gray-To-Blue-To-Violet Hydrogen-Rich Diamonds from the Argyle Mine, Australia

The Argyle diamond mine is the only known source of type IaB hydrogen- and nitrogen-rich diamonds colored gray to blue to violet.

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Nanocut Plasmaetched Diamonds
Cutting Diffraction Gratings to Improve Dispersion (“Fire”) in Diamonds

A new microlithography process developed to create high-resolution diffraction grating patterns on portions of certain facets can improve the dispersion of light and thus the amount of “fire” in a diamond.

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A wide range of jewelry pieces with the round brilliant diamond cut
A Foundation for Grading the Overall Cut Quality of Round Brilliant Cut Diamonds

The GIA diamond cut grading system described here includes the components of brightness, fire, scintillation, polish, and symmetry, as well as weight and durability concerns, into a single overall grade for cut quality for standard round brilliants.

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Computer Rendering of the “French Blue” Diamond
The French Blue and the Hope: New Data from the Discovery of a Historical Lead Cast

With the use of modern tools and technology, this article sheds light on the history and provenance of both the French Blue and the Hope diamonds.

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Characterizing Natural-Color Type IIB Blue Diamonds

More than 400 blue diamonds were studied at the GIA Gem Trade Laboratory over several years to reveal additional information about the relationships between their color, clarity, and other gemological properties.

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Whitish Graining with an Amorphous Appearance
The Impact of Internal Whitish And Reflective Graining on the Clarity Grading of D-To-Z Color Diamonds at the GIA Laboratory

This article reviews the GIA Laboratory’s history of reporting on certain types of graining which are often the only characteristics present in large, high-clarity, high-color diamonds.

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