CVD Synthetic Diamond Over 5 Carats Identified by GIA
Results from GIA’s recent testing of a 5.19 ct CVD synthetic diamond, the largest it has examined to date.
Aquamarine from a New Primary Deposit in Mexico
Examination of aquamarine samples from a new primary deposit in San Luis Potosí, northern Mexico.
Reversible Color Modification of Blue Zircon by Long-Wave Ultraviolet Radiation
Determines whether blue zircon, inadvertently altered to brown by exposure to long-wave UV radiation, can be restored to its original color through the use of incandescent light.
Natural-Color Blue, Gray, and Violet Diamonds: Allure of the Deep
Summarizes data collected on more than 15,000 natural blue/gray/violet diamonds examined by GIA during the last decade and examines the mechanisms that produce this color range.
Gemological Characterization of Sapphires from Yogo Gulch, Montana
A look at the mining and distinguishing characteristics of this naturally vibrant blue sapphire.
Features of Synthetic Diamonds
Presents a visual guide to the growth processes and major gemological spectroscopic features of synthetic diamonds.
A New Deposit of Gem-Quality Grandidierite in Madagascar
Reviews the properties of exceptionally pure grandidierite from a new source.
Natural Blister from Entombment of a Pearlfish Within a Pinctada Maxima Shell
A blister in a P. maxima shell, formed when the mollusk's nacre covered a trapped pearlfish, preserves the fish in stunning detail.
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.
Five CVD Synthetic Diamonds Greater Than Three Carats
The GIA lab examines five gem-quality CVD-grown diamonds in sizes that reflect the improving technology of the synthetic gemstone industry.