Back to gem encyclopedia

Opal

Fireworks. Jellyfish. Galaxies. Lightning. Opal’s shifting play of kaleidoscopic colors is unlike any other gem.

See gem as
Polished
Rough

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

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.

Inclusions in Natural, Treated, Synthetic, and Imitation Opal

Nathan D. Renfro, John I. Koivula, Jonathan Muyal, Shane F. McClure, Kevin Schumacher, and James E. Shigley, August 15, 2019

Provides a visual guide to the internal features of natural, treated, synthetic, and imitation opal.

Land of Origins: A Gemological Expedition to Ethiopia

Wim Vertriest, Daniel Girma, Patcharee Wongrawang, Ungkhana Atikarnsakul, and Kevin Schumacher, May 15, 2019

Documents a visit to the sapphire, opal, and emerald mining and trading areas of Ethiopia.

Boulder opal with layer of lepidocrocite inclusions

Lepidocrocite in Boulder Opal

Nathan Renfro and Bona Hiu Yan Chow, February 1, 2019

A boulder opal contained an unusual carpet of needle-like lepidocrocite inclusions along the interface between the opal and the ironstone matrix.

Article

Fall for Autumn Gems

Sharon Bohannon, September 21, 2018

Nature gives us a brilliant palette of color-changing leaves and a spectacular kaleidoscope of colorful sunsets during the fall season.

Bursts of yellow and purple radiate throughout this round cut amertrine.

Article

Colorblocking: The Art and Fashion of Multicolor Gemstones

Sharon Bohannon, July 20, 2018

The fashion trend of colorblocking can be found in the artistic combinations of color in multicolor gemstones known for their color zoning or banding.

A view from behind of a bejeweled winged insect.

Article

A Glittering Garden: A Menagerie of Designs from Mother Nature

Sharon Bohannon, May 21, 2018

Delightful garden creatures and flowers are favorite subjects that transform beautifully into Victorian, Art Nouveau and modern jewelry designs.

Outlook on Opals from Mexico and Australia

Duncan Pay and Jennifer-Lynn Archuleta, May 11, 2018

Jürgen Schütz discussed the opal sourcing and cutting activities of the German firm Emil Weis.

Indonesian opal cabochons, 6.94 and 3.79 ct.

Opal from West Java, Indonesia

Jennifer-Lynn Archuleta and Nathan Renfro, May 11, 2018

Description of Indonesian opal reportedly from West Java.

Flora and fauna brooches by Paula Crevoshay

Preview of Nature Art Science with Paula Crevoshay

Jennifer Stone-Sundberg and Andrew Lucas, May 11, 2018

Renowned designer Paula Crevoshay discusses artistic influences and her latest creations.

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

Opal

Research

Reviewed

Topics

Topics

Gemstones

Gemstones

Featured Gems

Peridot

Fancy Color Diamond

Diamond

Emerald

Citrine

Opal

Research

Reviewed

Topics

Topics

Gemstones

Gemstones

Featured Gems

Peridot

Fancy Color Diamond

Diamond

Emerald

Citrine

You Might Also Like

Find a Retailer

Shop the Campus Store

Grading Promotions

G&G Summer 2019 Edition