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Alexandrite
Green in sunlight. Red in lamplight. Color-changing alexandrite is nature’s magic trick.
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Tools
Research
Classification of Gem Materials Using Machine Learning
Explores the application of several machine learning models to complement traditional gem classification approaches.
Geographic Origin Determination of Alexandrite
The geographic source of this rare color-change gem has a significant impact on value. Trace element chemistry profiles allow GIA to accurately determine origin for alexandrite from several countries.
The Geographic Origin Dilemma
An overview of the geographic origin complexities facing the gem and jewelry industry today.
Field Gemology: Building a Research Collection and Understanding the Development of Gem Deposits
With more than 90 field expeditions on six continents since 2008, GIA has accumulated over 22,000 colored stone reference samples. This extensive collection of colored stones with known origins supports GIA’s research on geographic origin determination.
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.
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.
Cat’s-Eye Alexandrite with Unique Inclusion Pattern
Examination of a chatoyant alexandrite cabochon.
Importance of the Secondary Market for Fine Gems
Exceptional gems that are recirculated in the gem market make an impact at the Tucson shows.
“Red” Chrysoberyl versus Alexandrite: The Impact of Elevated Chromium Levels on Color and Color-Change Properties
Record-Size Natural Moissanite Crystals Discovered in Israel
Natural moissanite crystals found in Israel have broken world records, with evidence of larger crystals in the area.
