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Opal

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

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Cabochon

Most opals are cut as cabochons; this one from Ethiopia weighs 20.86 ct.

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Unique Beauty

The play-of-color displays the entire spectrum over a light gray background.

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Pattern

Bright flashes of color skip across this stone’s surface.

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Hidden Beauty

Opal forms as irregular nodules or seams in volcanic or sedimentary rocks.

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Rare Phenomena

Play-of-color results when light interacts with orderly stacks of spheres.

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Treasure

This opal nodule displays the promise of intense play-of-color.

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XClear Selections
NBA star Kevin Garnett, left, plays himself in
Article
The Real Gemology of Ethiopian Opals in ‘Uncut Gems’

Russell Shor, January 22, 2020

Taking a look at the rough opal that plays a major role in the Adam Sandler film “Uncut Gems.” What is the real gemology and source information of opals?

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An oval shaped 33.40 ct white Australian opal and diamond pendant/brooch set in platinum.
Article
The Enigmatic Gemstone: Opal’s Playful Dance with Light

Sharon Bohannon, September 20, 2019

Opal’s play-of-color is a lyrical dance: sometimes a grand jeté of bold, broad flashes of color or smaller, quicksteps of pinpoint flashes.

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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.

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Play-of-color is the defining characteristic of gem opals. While play-of-color can be quite spectacular under magnification, as with the roiled green patterns seen in this crystal opal, other microscopic features are often found if one takes the time to look. Field of view 9.60 mm. Photomicrograph by Nathan Renfro
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.

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GIA field expedition team in Ethiopia
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.

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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.

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A bright orange, multi-faceted gem.
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.

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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.

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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.

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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.

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