Seek the World’s Most Vivid Blue Spinel with GIA Field Gemologists
Join GIA’s field gemologists as they seek Vietnam’s exotic sky-blue spinel.
CVD Layer Grown on Natural Diamond
A composite of synthetically grown and natural diamond was recently identified by the Carlsbad laboratory.
The Largest Diamond Ever Discovered in North America
GIA examines a 552.7 ct diamond from the Diavik mine in Canada.
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.