A Synthetic Diamond Overgrowth on a Natural Diamond
Analysis of a diamond graded Fancy blue revealed a CVD synthetic overgrowth on natural diamond.
Partially Hollow Tridacna Blister Pearls with Shells Attached
Blister pearls attached to shells are seen in both the Bangkok and New York laboratories.
Dyed Yellow Beaded Freshwater Cultured Pearls Imitating South Sea Cultured Pearls
A yellow cultured pearl necklace is compared to the work of a producer specializing in freshwater pearls of all colors.
Sapphires from Northern Ethiopia
A new source of sapphires is found in the Tigray region of Ethiopia.
Christmas Tree–Shaped Internal Feature In Diamond
A laser manufacturing remnant in a Fancy yellow diamond creates a unique specimen.
Quarterly Crystal: Molybdenite Phantoms in Quartz
Raman analysis identifies unusual inclusions in quartz.
Atypical Bead-Cultured Pearls with Unusual Nacre Growth
Bead-cultured pearls with growth patterns within the drill holes are seen in the New York lab.
CVD Synthetic Diamond Mimicking Natural Stone
A round brilliant specimen, submitted for update service, is found to be a CVD synthetic diamond with post-growth annealing.
Diamond with Concentric Inclusions
A fancy-color diamond shows inclusions that outline growth layers.
HPHT Synthetic Diamond Melee Found In Mounted Jewelry
An HPHT synthetic diamond is found among the melee in a ring.
Tri-Color-Change Holmium-Doped Synthetic CZ
A synthetic cubic zirconia shows a surprising color change combination under different light sources.
“Sango Pearl” from Japan
A study of a pink Japanese akoya cultured pearl yields information about the material’s color origin.
Sapphires with Unusual Radial “Eye” Structure
Sapphires exhibiting radial structures are examined.
Melee Diamond Parcel Containing Nearly One-Third CVD Synthetics
GIA Melee Analysis Service reports a significant number of CVD synthetic diamonds in a parcel.
Summer 2017 G&G: Russian Diamonds and PL Mapping of Synthetic Diamonds, Plus Sapphire Inclusions Chart
A summary of the Summer 2017 issue of Gems & Gemology.
GIA发现覆合钻石
Analysis of a diamond graded Fancy blue revealed a CVD synthetic overgrowth on natural diamond.
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