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

A look at a 34.59 ct CVD-grown diamond examined at GIA’s Hong Kong laboratory.

An iridescent feather inclusion in natural diamond bears resemblance to Rainbow Mountain in Peru.

Unusual natural pink diamonds displaying faint yellow color zoning and strong yellow fluorescence are studied in the Carlsbad laboratory.

Isolated nitrogen confined to the outer surface of a 0.98 ct diamond causes “yellow skin.”

A feather inclusion with iridescence caused by thin-film interference in diamond resembles an insect wing.

Various inclusions are observed in a batch of aquamarine samples from Xinjiang, China.

A look at a very rare instance of a six-rayed star in aquamarine.

Reports on a newly discovered treatment process for producing a deep blue color in natural spinel and proposes identification criteria.

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A look at a rare volcanic glass from central Oregon with lapidary artist Tom Dodge.

Investigates the mineral and chemical compositions and surface morphology characteristics of brown mammoth ivory to identify the origins of its brown color.

Offers a comprehensive look at a variety of augite from Dong Nai, Vietnam, detailing its formation and gemological characteristics.

Gemstones formed in metamorphic environments offer insights into the earth’s history and the evolution of tectonic activity that led to their formation.

A hexagonal platelet of graphite is discovered in a pink sapphire from Sri Lanka.

Analysis of internal structures in non-bead cultured pearls submitted to GIA’s Mumbai laboratory.

Examination of a natural diamond reveals graining and zoning that resemble those of a laboratory-grown CVD diamond.

Two pearls representing Indian deities were recently examined in the Mumbai laboratory.

Examination of natural pearls from Kuwait reveals one with a suspected metal oxide at the core.

An overview of the Summer 2023 Gems & Gemology content.