
Dyed Non-Nacreous Pearls
Four pearls submitted to the Bangkok lab proved to be natural non-nacreous specimens dyed pink, apparently to imitate true conch pearls.

Fossilized Shell Consisting of Emerald
Several shells received at the Hong Kong laboratory were identified as fossils replaced by emerald crystals.

Glass Imitation of Star Sapphire
A fixed star indicating manufactured asterism helps to identify an imitation star sapphire.

HPHT-Processed Diamond with Counterfeit GIA Inscription
Careful comparison of two GIA reports reveals a fraudulent inscription on a laboratory-produced diamond presented as a natural.

Laboratory-Grown Diamond with Internal Laser Markings
Accidental laser damage likely caused unusual internal spiral markings in a 2.44 ct CVD-grown diamond.

Zircon with Unusual Color-Change Behavior
The Carlsbad laboratory recently had the chance to examine a 4.60 ct cushion-cut zircon with truly unusual color behavior.

New CVD Material Submitted for Analysis (英语)
A group of large, high-quality CVD material demonstrates the continued challenge of identifying laboratory-grown gems.

A Unique Double Cat’s-Eye Emerald
The Tokyo lab examined a stunning double cat’s-eye emerald whose chatoyancy was created both by its cut and its inclusions.

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