Careful comparison of two GIA reports reveals a fraudulent inscription on a laboratory-produced diamond presented as a natural.

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

A group of large, high-quality CVD material demonstrates the continued challenge of identifying laboratory-grown gems.

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

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

Several shells received at the Hong Kong laboratory were identified as fossils replaced by emerald crystals.

A fixed star indicating manufactured asterism helps to identify an imitation star sapphire.

Accidental laser damage likely caused unusual internal spiral markings in a 2.44 ct CVD-grown diamond.