Atypical Color Center in Natural Pinkish Brown Diamond

Atypical absorption spectral features are observed in a natural pear brilliant diamond previously submitted as rough to GIA.

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Carved Natural Diamond Panther Face

The Mumbai laboratory reports on a unique carved natural diamond set with two Zambian emeralds.

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Large South Sea Bead Cultured Pearl with Mille-Feuille Structure

Examination of an extraordinarily large bead cultured pearl reveals an unusual internal structure characterized by widely spaced concentric nacre layers separated by translucent organic material.

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Microscopic Marine Organisms in South Sea Cultured Pearls

The Bangkok laboratory documents the first reported discovery of microscopic marine organisms observed in South Sea cultured pearls at GIA.

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Reversible Photochromism in a Heat-Treated Sri Lankan Sapphire

A heat-treated Sri Lankan sapphire exhibits a rare reversible color change from very light blue to light yellow after short-wave UV exposure.

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Heat-Treated Red Spinel

A purplish red oval mixed cut submitted as a ruby was recently identified as heat-treated spinel at the Hong Kong laboratory.

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Twinned Calcite with Realgar Inclusions

Vivid red to orange-red realgar inclusions are observed in a contact-twinned calcite host.

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“Fungal Hyphae” in a Mabe Pearl

A mabe pearl exhibits an unusual pattern of intersecting subsurface channels, likely formed by shell-boring parasites.

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Leaf-Like Imprint on Non-Nacreous Pearl

Microscopic examination of a non-nacreous natural pearl reveals a distinctive pattern resembling leaves with intricate vein structures.

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Reticulated Pattern on Pearl’s Surfaces

Several natural pearls in a multistrand necklace display an unusual reticulated surface texture with deep indentations and prominent ridges.

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Two-Phase Inclusion in Peridot

Microscopic examination of a Pakistani peridot reveals a rare cylindrical fluid inclusion with a freely moving gas bubble.

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Colorful Mosaic Pattern in Heated Orange Sapphire

Thin-film decrepitation inclusions create a colorful scene in a beryllium-diffused orange sapphire.

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“Shooting Stars” in Sapphire

Numerous Rose channels against a backdrop of scattered zircon crystals produce a striking night-sky effect in a color-change sapphire.

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Vesuvianite in Sapphire

The first known occurrence of a vesuvianite inclusion in sapphire is documented.

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Distinctive Fluorescent Crystal Inclusions in Spinel

A cluster of transparent inclusions in spinel displays various fluorescent colors under short-wave ultraviolet light.

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Quarterly Crystal: Chromite in Diamond

A partially etched colorless diamond octahedron hosts numerous opaque black chromite crystals.

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Baw Mar Sapphire, China’s Freshwater Pearl Industry, Glass-Ceramic Imitation Gemstones, and Red and Orange Spinel from Myanmar and Vietnam

An overview of the Summer 2026 Gems & Gemology content.

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GIAとギューベリン宝石研究所がエチオピア産銅含有トルマリンの新しい供給源を確認

GIAとギューベリン宝石研究所の研究者がパライバトルマリンの新しい供給源を確認

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74th Bangkok Gems & Jewelry Fair Trade Show

Join us at the Bangkok Gems & Jewelry Fair to explore a diverse range of gemstones, jewelry and industry solutions from leading Thai and international suppliers. Discover tools, components and machinery for the trade, and attend GIA seminars on pearls and diamond fluorescence.

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Former GIA Governor Dr. Gordon E. Brown, Jr. Passes Away

CARLSBAD, Calif. – September 8, 2026 – Gordon E. Brown, Jr., a member of the GIA Board of Governors from 1988 to 2008 passed away in August.

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