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Alexandrite

Green in sunlight. Red in lamplight. Color-changing alexandrite is nature’s magic trick.

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Chrysoberyl Variety

Alexandrite is the color-change variety of the mineral chrysoberyl.

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Green by Day

Alexandrite is bluish green in daylight or fluorescent light.

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Red by Night

Alexandrite is purplish red in incandescent light or candlelight.

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Star-shaped Twin

This alexandrite specimen is made up of three interpenetrant crystals.

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Brazilian Gem

Brazil is one of the most important alexandrite sources.

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Re-entrant Angle

Notches marking the edge of each crystal are called re-entrant angles.

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Tools

Research

A large group of people outside on GIA’s Carlsbad, California  campus.
Article
Guardians of Trust: GIA’s Innovative Research, Instruments and Services

GIA’s services and instruments have grown in importance and impact as new gem treatments and laboratory-grown gems enter the market.

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Interference figures in faceted alexandrite
Pleochroism and Color Change in Faceted Alexandrite: Influence of Cut and Sample Orientation

Shows how alexandrite’s color and color change are affected by cut and the orientation of table facets.

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Alexandrite cabochon in fluorescent (left) and incandescent light (right).
Cat’s-Eye Alexandrite with Unique Inclusion Pattern

Examination of a chatoyant alexandrite cabochon.

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Copper-bearing tourmaline acquired on the secondary market.
Importance of the Secondary Market for Fine Gems

Exceptional gems that are recirculated in the gem market make an impact at the Tucson shows.

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Three pieces of labradorite with yellow, blue and green flashes of color.
Article
Optical Effects of Phenomenal Cabochons

Learn how the structure, inclusions and properties of some gemstones interact with light to create unusual visual effects.

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Worker attaching wax forms
Article
Shenzhen: The Frontier of China’s Gem and Jewelry Industry

All jewelry professionals are familiar with the city of Shenzhen, a global jewelry manufacturing center and a leader of China’s fast-growing gem and jewelry industry. Join the GIA team as we tour the city and discover more about its leading jewelry brands.

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Article
The Glory of Green Gems

Green gemstones, which can uplift and heal our spirits, have been popular gem choices ever since we began to adorn ourselves with jewelry.

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Article
Gemologist’s Black Opal Ring Wows Consumer, Trade Media

GIA grad Niveet Nagpal, president and head designer of Omi Privé, showcases his love of gems and brings them to life in his designs.

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“Red” Chrysoberyl versus Alexandrite: The Impact of Elevated Chromium Levels on Color and Color-Change Properties

Overview and commentary on the 2014 Journal of Gemmology article “Purple to Reddish Purple Chrysoberyl from Brazil.”

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14 ornaments of coral veneer glued to matrix
Composite Coral Veneer Glued to Artificial Matrix

Items presented as red coral are revealed by testing to be composite coral veneers over an artificial matrix.

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