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Tourmaline
Tourmalines have a variety of exciting colors with one of the widest color ranges of any gem.

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Research
Stars Are Out in Paraíba Tourmaline
Rare material from Brazil features four-ray stars under point-source light.
Bicolor Double-Eye Tourmaline
Unique Tourmaline Necklace
An unusual parti-color tourmaline necklace and clasp are seen at the 2015 AGTA show in Tucson.
Larger Optic Disks
Exceptional innovations using gem and mineral rough at Tucson’s GJX show.
Large and Unusual Gems
High-End Colored Gems
From Brazil to China: The Journey of Rubellite Tourmaline
After documenting tourmaline production at the famous Cruzeiro mine in Brazil, GIA takes you to China, where you can witness the cutting of these stones for entry into the hottest tourmaline market in the world.
Expedition to the Cruzeiro Tourmaline Mine in Minas Gerais, Brazil
Journey with us to Brazil for a visit to one of the world’s most prolific tourmaline mines. You’ll also hear a highly captivating story of family success through perseverance.
An Overview of the 2014 GIA Brazil Expedition
Join GIA’s field gemologists as they venture into some of Brazil’s most important and productive emerald and tourmaline mines.
Exhibition Review: Mogul to Modern: Met Exhibit Showcases Indian Jewels
Examines a collection of Indian and Indian-inspired jewelry on display at New York's Metropolitan Museum of Art.
Pleochroism in Faceted Gems: An Introduction
Describes the phenomenon of pleochroism and its complex effect on the appearance of colored stones.









