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Feature Article

An Early Byzantine Engraved Almandine from India

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Feature Article

Cause of Color in Black Diamonds

from Zimbabwe

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September Birthstone

The Royal Choice from

Ancient Rome to Modern Britain

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featured

Research & News

These rubies were determined to be glass filled, partly due to the use of the DiamondView.
Gem News International

Separating Glass-Filled Rubies Using the DiamondView

The DiamondView instrument is able to identify glass as the filler in a pair of heart-shaped rubies.
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Circular logo with the words “International GIA Gemological Symposium” around the outside and a star with a diamond center in the center circle.
Event

2018 GIA Symposium

Scientists and business leaders will gather at a summit of the gem and jewelry industry.
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Six-rayed star in an untreated spinel.
Micro-World

Star Spinel with Four and Six Rays

A cabochon displaying asterism is found to be an untreated spinel with two different stars.
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Garnets under daylight-equivalent (left) and incandescent light (right).
Gem News International

Color-Change Chrome Grossular Garnets from Ethiopia

The first known group of color-change gem-quality chrome grossular garnet, reportedly from Ethiopia, is examined in GIA’s Carlsbad lab.
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The repaired diamond.
Lab Notes

A Repaired Diamond

A marquise-cut diamond is found to have been broken and reassembled with an unknown adhesive.
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Sapphire cabochon displaying asterism.
Lab Notes

Unique Star Sapphire with Transparent Core

A sapphire cabochon with an unusual appearance is seen at GIA’s Tokyo lab.
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Learn & Connect

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Engagement Rings

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in Gems & Jewelry

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Gems & Gemology
This Month's

Featured Gems

Featured Gem Peridot
Peridot

Found in lava, meteorites, and deep in the earth’s mantle, yellow-green peridot is the extreme gem.
Fancy Color Diamond
Fancy Color Diamond

Dazzling brilliance. Captivating color. These are the planet’s most valued gems.
Diamond
Diamond

Diamonds are among nature’s most precious and beautiful creations.
Emerald Bluish Green Stone
Emerald

Emerald is the bluish green to green variety of beryl, a mineral species that includes aquamarine.
Featured Gem Citrine
Citrine

Citrine is the transparent, pale yellow to brownish orange variety of quartz.

View the Gem Encyclopedia

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