Cat's-Eye Demantoid and Brown Andradite with Horsetail Inclusions
The examination of two unusual garnets results in identifications issued for the first time in GIA's colored stone report records.
DNA Techniques Applied to the Identification of Pinctada Fucata Pearls from Uwajima, Ehime Prefecture, Japan
Shows how genetic material extracted from small amounts of pearl powder can be a useful indicator of this akoya cultured pearl species.
Natural-Color Green Diamonds: A Beautiful Conundrum
Characterizes diamonds with exceptionally rare natural green color, based on GIA’s extensive database of samples.
Unusual Orange Pyrope-Spessartine-Grossular Garnet
A garnet proves to have a much higher grossular component than initially expected.
Very Small Akoya Cultured Pearls
A selection of very small akoya cultured specimens demonstrates the challenges gemologists face when determining pearl origin.
HPHT-Processed Diamond Fraudulently Represented as Untreated
An HPHT-treated round brilliant diamond with an inscription that presents as a GIA report number is found to be inconsistent with the institute's report, previously issued for an untreated diamond.
Atypical “Beading” in the Production of Cultured Pearls from Australian Pinctada Maxima
In 2011, the authors began to see cases of low-quality natural pearls being used as unconventional “beads” for cultured nacre growth.
Akoya Cultured Pearl Farming in Eastern Australia
Characterizes the akoya cultured pearls produced on the eastern shoreline of Australia using native Pinctada imbricata fucata mollusks.
Inclusions in Natural, Synthetic, and Treated Ruby
Provides a visual guide to the internal features of natural, synthetic, and treated rubies.
Real-Time Microradiography of Pearls: A Comparison Between Detectors
Compares the image quality provided by real-time microradiographic imaging (RTX) units fitted with two different detectors: an image intensifier (II) and a flat panel detector (FPD).