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Figure 1. A natural 47.77 ct Ethiopian opal with an unusual play-of-color pattern. Photo by Nuttapol Kitdee.

Natural Opal with Unusual Play-of-Color Pattern

Ungkhana Atikarnsakul, November 17, 2025

Play-of-color pattern in Ethiopian opal is reminiscent of a turtle’s shell.

Group of aragonite snowflake inclusions in opal likely from Ethiopia. Photomicrograph by Narint Jaisanit; field of view 1.80 mm.

Snowflakes in Opal

Narint Jaisanit, June 5, 2025

A group of aragonite snowflake inclusions is observed in an opal likely from Ethiopia.

Figure 1. A black opal cabochon displaying orange play-of-color when viewed face-up. Photo by Annie Haynes.

Black Opal with Unique Play-of-Color

Jessa Rizzo, June 5, 2025

A black opal cabochon set in a ring displays vivid orange play-of-color.

Figure 1. A pattern resembling Chinese characters in an 8.13 ct black opal. Note that blade-like play-of-color patches exist within common opal. Photomicrograph by Makoto Miura; field of view 12.06 mm.

Written Characters in Black Opal

Makoto Miura, November 1, 2024

Play-of-color patches in black opal display interesting written character patterns.

Figure 1. Pedro II is the most important opal source in Brazil. The town is located in the northeast of the state of Piauí, and opal deposits are distributed in an area about 20 km in diameter around the township. The current opal mine is an open-pit operation. Photo courtesy of Prime Gems.

Precious Opal from Pedro II, Brazil

Tao Hsu, May 3, 2024

A look at the variety of rough and finished Brazilian opal offered by Prime Gems at the GJX show.

Blue Opal from Chile

Cristiano Brigida, May 3, 2024

A look at the variety of rough and finished Brazilian opal offered by Prime Gems at the GJX show.

IFigure 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.

The front of the “Blue Boy” chest features two wing-like “conk” wood opal slices from Nevada.

Intarsia Jewelry Box by Nicolai Medvedev and Susan Helmich

Eric Fritz, May 3, 2024

Opening day at the AGTA GemFair included the unveiling of the “Treasure Chest II with Blue Boy” intarsia jewelry box.

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.

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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