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Alexandrite

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

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Research

A large group of people outside on GIA’s Carlsbad, California campus.

Article

Guardians of Trust: GIA’s Innovative Research, Instruments and Services

Russell Shor, September 20, 2019

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

Interference figures in faceted alexandrite

Pleochroism and Color Change in Faceted Alexandrite: Influence of Cut and Sample Orientation

Karl Schmetzer, May 15, 2019

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

Alexandrite cabochon in fluorescent (left) and incandescent light (right).

Cat’s-Eye Alexandrite with Unique Inclusion Pattern

Makoto Miura and Yusuke Katsurada, January 26, 2018

Examination of a chatoyant alexandrite cabochon.

Copper-bearing tourmaline acquired on the secondary market.

Importance of the Secondary Market for Fine Gems

Duncan Pay, May 8, 2017

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

Three pieces of labradorite with yellow, blue and green flashes of color.

Article

Optical Effects of Phenomenal Cabochons

Sharon Bohannon, November 10, 2016

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

Article

Shenzhen: The Frontier of China’s Gem and Jewelry Industry

Tao Hsu, and Andrew Lucas, January 25, 2016

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.

Article

The Glory of Green Gems

Sharon Bohannon and Peggy Tsiamis, June 12, 2015

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

Article

Gemologist’s Black Opal Ring Wows Consumer, Trade Media

Jaime Kautsky, May 8, 2015

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

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

Jennifer Stone-Sundberg , October 31, 2014

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

14 ornaments of coral veneer glued to matrix

Composite Coral Veneer Glued to Artificial Matrix

Haibo Li, Zhoujing Yue, Jie Liang, Taijin Lu, Jun Zhang, and Jun Zhou , July 25, 2014

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

This Month's

Featured Gems

Peridot

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

Fancy Color Diamond

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

Diamond

Diamonds are among nature’s most precious and beautiful creations.

Emerald

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

Citrine

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

View the Gem Encyclopedia

Alexandrite

Research

Reviewed

Topics

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Gemstones

Gemstones

Featured Gems

Peridot

Fancy Color Diamond

Diamond

Emerald

Citrine

Alexandrite

Research

Reviewed

Topics

Topics

Gemstones

Gemstones

Featured Gems

Peridot

Fancy Color Diamond

Diamond

Emerald

Citrine

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