How GIA Analyzes Pearls from Start to Finish

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Amit Pratihari 獲任命為 GIA India Laboratory Pvt. Ltd.董事總經理

The board of directors of GIA India Laboratory Pvt. Ltd. (GIA India) has appointed Amit Pratihari as managing director, responsible for all aspects of GIA India’s gemological laboratories in Mumbai and Surat, as well as the GIA India school in Mumbai.

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Amit Pratihari Named Managing Director, GIA India Laboratory Pvt. Ltd.

The board of directors of GIA India Laboratory Pvt. Ltd. (GIA India) has appointed Amit Pratihari as managing director, responsible for all aspects of GIA India’s gemological laboratories in Mumbai and Surat, as well as the GIA India school in Mumbai.

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How GIA Analyzes Colored Stones from Start to Finish

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Quarterly Crystal: Unique Phantom in Diamond

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“Sugar Plum” in Titanium-Diffused Blue Sapphire

A sugar plum–like frosted zircon cluster is observed in a blue sapphire.

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Diamond Trader Ishaia Gol

A look at Ishaia Gol’s extraordinary career as a diamond dealer.

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Well-Formed Rutile Star in Quartz

Rutile needles intersect to form a star in colorless quartz.

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Quartz Assemblage Imitating Emerald

A green stone in a pendant necklace is identified as a quartz assemblage at the New York laboratory.

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Mystery Pebbles in Quartz

Amphibole pebbles in quartz resemble rocks stacked in a stone wall.

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Pezzottaite with Multiple Cat’s-Eyes

The Tokyo laboratory examined a purplish pink pezzottaite cabochon displaying multiple cat’s-eyes.

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New Väyrynenite Production from Nigeria

A new source of väyrynenite produces specimens in larger sizes with higher clarities than material from other sources.

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Monazite in Quartz

Numerous monazite crystals are observed in colorless quartz.

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Imitation Seed Pearl with Blue X-Ray Fluorescence

X-ray fluorescence screening is used to identify an imitation in a submission of more than 9,000 seed pearls.

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Lithiophilite in Quartz

A well-formed lithiophilite crystal is identified in colorless quartz.

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Iridescent Gems Cut from Hinge Ligament of South Sea Pearl Oyster (Pinctada maxima)

Biogenic material from a pearl oyster is used to produce a new eye-catching blue-green iridescent gem material.

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Three Large Natural Hollow Pinctada radiata Pearls

Three large natural pearls with hollow interiors reportedly from Bahrain are studied in the Mumbai laboratory.

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HPHT-Processed Natural and Laboratory-Grown Diamonds with Counterfeit Inscriptions

The Dubai laboratory reports on four diamonds inscribed with fraudulent GIA report numbers.

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Exceptional Nacre Thickness of Hybrid Akoya Bead Cultured Pearls

GIA’s Bangkok laboratory reports on a hybrid mollusk species that can produce bead cultured pearls with a thicker nacre layer.

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CVD-Grown Diamond with Unusual Cause of Greenish Color

A previously unidentified cause of green color in CVD-grown diamonds is detected for the first time in a diamond submitted to the Carlsbad laboratory.

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