Back to gem encyclopedia

Tourmaline

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

Responsive image

Responsive image

See gem as
Polished
Rough

Tools

Research

Figure 1. Two pieces of “Paraíba matrix” weighing 4.23 ct (sample PB1, left) and 3.67 ct (PB2, right). Photo by Xinchenlu Ai.

Mineral Assemblage of “Paraíba Matrix”

Xinchenlu Ai and Xiaojing Lai, November 1, 2024

The contents of two “Paraíba matrix” samples are analyzed.

Read More

Figure 1. A moiré-pattern metallic inclusion was observed in the 0.33 ct Paraíba tourmaline. Photo by Shunsuke Nagai.

Unique Moiré-Pattern Metallic Inclusion in Paraíba Tourmaline

Kanako Otsuka and Yusuke Katsurada, August 2, 2024

An intriguing inclusion scene is analyzed in a Paraíba tourmaline from Brazil.

Read More

This collection of 50 tourmalines showcases the gem’s wide-ranging color palette. Photo by Robert Weldon; courtesy of Bruce A. Fry.

Micro-Features of Tourmaline

Nathan Renfro, Tyler Smith, John I. Koivula, Shane F. McClure, and James E. Shigley, August 2, 2024

Provides a visual guide to the internal features of tourmaline as well as tourmaline inclusions in other gem hosts.

Read More

These 18 × 18 × 4 mm watermelon tourmaline slices (17.82 ct on the left and 17.17 ct on the right) display an exceptional iris effect. Photo by Jeffrey Scovil.

Brazilian Watermelon Tourmaline with Iris Effect

Russ Behnke, May 3, 2024

A pair of watermelon tourmaline slices from the Cruzeiro mine displays a rainbow of colors.

Read More

Heitor Barbosa discovered Paraíba tourmaline in 1989 after almost a decade of mining. Photo by Duncan Pay.

In Memoriam: Heitor Barbosa

GIA Staff, January 26, 2024

The life of the discoverer of Paraíba tourmaline is remembered.

Read More

Figure 1. A 2.52 ct oval modified brilliant Paraíba tourmaline. Photo by Adriana Gudino.

Interesting Metallic Platelets in a Brazilian Paraíba Tourmaline

Shiva Sohrabi and Amy Cooper, August 4, 2023

Microscopic observation unveils the first known instance of skeletal metallic inclusions in Brazilian Paraíba tourmaline.

Read More

Figure 1. A 16.96 ct emerald-cut green tourmaline from rough found near a new pocket at the Tourmaline King mine. Photo by Robert Weldon; courtesy of Pala International.

New Tourmaline Pockets in San Diego County’s Pala District

Erin Hogarth, May 23, 2023

Bill and Carl Larson share details about new tourmaline pocket discoveries at the Tourmaline King mine.

Read More

The copper inclusions produce a golden chatoyancy.

Cat’s-Eye Paraíba Tourmaline with Copper Inclusions

Yuxiao Li, November 11, 2022

The Tokyo laboratory examines a Paraíba tourmaline with chatoyancy caused by copper inclusions.

Read More

This 1.21 ct diamond exhibits a natural red color.

Exceptional Natural-Color Fancy Red Diamond

Maryam Mastery Salimi, November 11, 2022

An extremely rare natural-color red diamond is submitted to the Carlsbad laboratory.

Read More

This Paraíba tourmaline contains a set of stellate zircon needles.

Stellate Zircon in a Paraíba Tourmaline

Nicole Ahline, November 11, 2022

Fiber-optic light reveals a remarkable set of stellate inclusions in blue-green Paraíba tourmaline.

Read More

Load More

This Month's

Featured Gems

reading

Peridot

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

reading

Fancy Color Diamond

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

reading

Diamond

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

reading

Emerald

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

reading

Citrine

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

View the Gem Encyclopedia