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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
Figure 1. A silver brooch containing a large Slovak opal (77 ct, 34.5 × 25 × 13 mm) and 48 diamonds. The opal was initially purchased for Louis XVIII’s personal collection. In 1824, it adorned the clasp of Charles X’s coronation mantle, and around 1853 it was remounted onto this brooch for Empress Eugénie, which has been preserved. Photo by Peter Semrád; courtesy of the National Museum of Natural History in Paris (inventory no. MNHN 87.44).
Slovak Opal: A New Life for a Historical Gem

Peter Semrád, January 26, 2024

Reports on the recent production of precious and common opal from a centuries-old locality.

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Figure 1. An 11.68 ct treated phantom opal in which the phantom structure appeared during experiments with various solutions. The sample is shown under daylight through the dome (left) and under halogen lighting through the bottom (right). Photos by Le Ngoc Nang.
A New Treatment: Creating Phantom Structure in Opal

Le Ngoc Nang and Pham Minh Tien, August 4, 2023

A newly developed treatment creates a phantom structure in opal visually similar to natural phantom opal.

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Figure 1. The Heart of Australia, a 3,510 ct double pseudomorph ikaite-calcite-opal gem specimen, is considered one of the finest ever unearthed. Courtesy of Graeme Dowton.
Rare Double Pseudomorph Ikaite-Calcite-Opal

Si Athena Chen and Jennifer Stone-Sundberg, May 23, 2023

One of the finest specimens of double pseudomorph ikaite-calcite-opal ever unearthed was on display at the Pueblo Gem & Mineral Show.

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Andrew Cody, one of Australia’s leading opal experts.
In Memoriam: Andrew Cody

GIA Staff, November 11, 2022

The life of one of Australia’s leading opal authorities is remembered.

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Ahmadjan Abduriyim (left) receives the 2021 JAMS award for applied mineralogy.
Ahmadjan Abduriyim Receives JAMS Award for Applied Mineralogy

Erica Zaidman, November 11, 2022

Ahmadjan Abduriyim receives 2021 JAMS award for his contributions to applied mineralogy.

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A 10.65 ct black opal from Lightning Ridge shown in diffused and direct lighting.
Social Media Success for Black Opal Direct

Erin Hogarth, May 13, 2022

Black Opal Direct’s use of social media increases sales during the COVID-19 pandemic.

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A 13.12 ct black opal from Lightning Ridge.
Conversation with True Blue Opals and Gems

Erin Hogarth, May 13, 2022

The mother/daughter team behind True Blue Opals and Gems in Australia shifts focus from Lightning Ridge black opal to Yowah and Koroit boulder opal during the COVID-19 pandemic.

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Purple fluorite cube inclusion in a hyalite.
Hyalite with Magnificent Internal Features

Ugo Hennebois, Aurélian Delaunay, Stefanos Karampelas, and Emmanuel Fritsch, May 13, 2022

Pronounced cubic cavities, sometimes containing fluorite, are observed in a rare hyalite sample.

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“Andamooka matrix opal” as rough, after treatment, and a finished freeform cabochon.
Sugar/Heat-Treated Opal

Tao Hsu and Lisa Kennedy, May 13, 2022

At the AGTA show, lapidarist James Carpenter explains his use of sugar/heat treatment to enhance opal.

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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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