A “Flying Insect” in Diamond

A partially exposed orange garnet inclusion with surrounding fractures resembles a flying insect in a brownish yellow diamond.

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Pink Pyrope Garnet

A rare example of pink pyrope garnet is examined in the Carlsbad laboratory.

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“Atypical Beads”: Variations of Two Types of Nuclei

Four atypical bead cultured pearls with variations on two types of nuclei are examined in the Mumbai laboratory.

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Morphology of Colombian Emerald: Some Less-Common Cases and Their Growth and Dissolution History

Evaluates the growth mechanisms of special morphological features in Colombian emerald, including possible relationships to trapiche emeralds and samples displaying the gota de aceite effect.

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Ruby with Interesting Synthetic Overgrowth

Microscopic examination of a ruby at the Carlsbad laboratory reveals synthetic overgrowth indicative of high-temperature heat treatment.

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CVD Diamond Over 34 Carats Examined in GIA’s Hong Kong Laboratory

A look at the largest CVD diamond GIA has encountered to date.

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Color Modification of Spinel by Nickel (Ni) Diffusion: A New Treatment in the Gem Market

GIA researchers report on a new nickel-diffusion treatment used to modify color in spinel and present criteria for identification.

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A Closer Look at Internal Etch Channels in Diamond

The Carlsbad laboratory reports on a Fancy Deep brownish yellowish orange diamond featuring trigons within subsurface etch channels.

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Fluorescence Characteristics of Two Copper-Diffused Plagioclase Feldspars: Labradorite and Andesine

Examines the use of strong fluorescence near 394 nm under 320 nm excitation as a potential means of identifying copper diffusion treatment of feldspar.

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Extremely Rare Hellandite Inclusion Found in a Mogok Ruby

A rare inclusion is reported in ruby from the Mogok mine for the first time.

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An Extraordinarily Large Cat’s-Eye Emerald

The Tokyo laboratory examines a 126 ct cat’s-eye emerald from Brazil.

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“Electromagnetic Wave” Inclusion in Mong Hsu Ruby

Fiber-optic illumination reveals an electromagnetic wave-like pattern of particles in a ruby from Myanmar.

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Gems Formed in Magmatic Rocks

This installment of “Colored Stones Unearthed” covers gemstones that formed in magmatic environments and the insights they offer into the evolution of the earth and the geological processes that shaped our world.

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A Partially Hollow Natural Blister Pearl Filled with Foreign Materials

A very large baroque white pearl is further examined in the Mumbai laboratory due to its suspicious heft.

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Fall 2022 Auction Highlights

A successful spring season set high expectations for colored diamonds at auction in late 2022.

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Unusual “Horsetail” and Columnar Inclusions in Demantoid

Examination of a yellowish green demantoid reveals fibers of serpentine in a randomly curved pattern and a columnar two-phase negative crystal.

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Never Stop Innovating: Gem Artist Chi Huynh

Profiles a groundbreaking gem artist on a quest to bring new concepts, techniques, and products to the industry.

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Composition and Spectral Characteristics of Porcelain-Treated Turquoise

Characterizes turquoise treated with an inorganic additive that dramatically improves the luster and color of low- and medium-quality material.

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A Canary in the Ruby Mine: Low-Temperature Heat Treatment Experiments on Burmese Ruby

Documents heating experiments conducted on Burmese rubies to find useful indicators of heat treatment at temperatures below 1200°C.

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Omphacite in Pink Diamond

A bluish green omphacite crystal is discovered in a Fancy brown-pink diamond.

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