Effects of Blue Fluorescence on Diamond Appearance

Gems & Gemology

The Effects of Blue Fluorescence on Diamond Appearance

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DOR Image Collection

Laboratory Service

GIA Diamond Origin: A Program That Makes a Difference

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October 2021 birthstone opal

October Birthstone

Opal: A Kaleidoscope of Color

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GIA iD100 Probe with Ring

GIA iD100®

GIA iD100 Gem Testing Device: Full Disclosure at Your Fingertips

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Research & News

Carved bangle composed of a coral-epoxy composite.
Gem News International

Calcareous Coral and Epoxy Composite

Meticulous testing of a bangle submitted to a Taiwan gemology lab proves it to be a composite of red calcareous coral and epoxy.
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Knowledge Session Webinars
Webinar Series

GIA Knowledge Sessions

Engage in webinars on the most diverse and pressing issues in gemology today, including gemstone origin, laboratory-grown stones and new discoveries in field gemology.
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Brownish red “bent” rutile.
Micro-world

Bent Rutile in Rock Crystal Quartz

Normally straight and fine, rutile needles take an unexpected bend in the polished quartz disk that is their host.
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A counterfeit GIA inscription was found on this CVD laboratory-grown diamond.
Lab Notes

CVD Laboratory-Grown Diamond with Counterfeit GIA Inscription

A CVD laboratory-grown diamond with a fraudulent GIA inscription is submitted to the Antwerp lab.
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Diamond paper containing the briolette.
Gem News International

Hole Drilled by Hand in Briolette

A centuries-old diamond featuring a hand-drilled hole inspires an investigation of the briolette cutting style and the history of drilling diamonds.
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Flux-grown synthetic ruby.
Lab Notes

Chrysoberyl Inclusions in Flux-Grown Ruby

Natural-looking chrysoberyl crystals appear in a flux-grown ruby with a high beryllium content but lacking heat treatment.
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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