Very Large Irradiated Yellow Diamond
A very large diamond with a Fancy Vivid yellow color was identified as artificially irradiated.
Diamonds from the Deep: How Old Are Diamonds? Are They Forever?
Age dating diamonds, which have been forming for billions of years, using isotope analyses reveals new information about the deep earth.
For the first time, GIA's laboratory has examined tanzanite color-coated with titanium.
Imitation Rainbow Moonstone Assemblage
Examination of an imitation rainbow moonstone assemblage containing plastic-coated gypsum.
Turquoise with Simulated Matrix
A turquoise bead is found to have an artificial pyrite and resin matrix.
Turquoise from Western Arkansas
A report on turquoise from the only known U.S. deposit outside of the Southwest.
Chart: Inclusions in Natural, Synthetic, and Treated Diamond
Provides a visual guide to the internal features of natural, synthetic, and treated diamonds.
Sapphires from Australia
An overview of Australia's recent significance in the production of blue sapphire.
Chart: Inclusions in Natural, Synthetic, and Treated Ruby
Provides a visual guide to the internal features of natural, synthetic, and treated rubies.
Diamonds from the Deep: How Do Diamonds Form in the Deep Earth?
G&G’s newest section explores how diamonds form in the deep earth.