An A-maze-ing Fingerprint in Spinel
A maze-like pattern is observed in spinel from Vietnam.
Red spinel from Vietnam features iridescent needles resembling a futuristic skyline.
Gray “Spinel Sisters”
Two rare gray spinel stones stand out at the AGTA show for their exceptional size, quality, and color.
Purple Gem Spinel from Vietnam and Afghanistan: Comparison of Trace Element Chemistry, Cause of Color, and Inclusions
A chemical and spectroscopic comparison of two purple gem spinel samples, one of them the first reported example of a spinel with a saturated purple color caused predominantly by chromium and cobalt.
Micro-Features of Spinel
Provides a visual guide to the internal features of natural, synthetic, and treated spinel, as well as inclusions of spinel in other gemstones.
Field Gemology: Building a Research Collection and Understanding the Development of Gem Deposits
With more than 90 field expeditions on six continents since 2008, GIA has accumulated over 22,000 colored stone reference samples. This extensive collection of colored stones with known origins supports GIA’s research on geographic origin determination.
2019 in Review: Diamond Trade Begins Recovery, Jewelry Retail Blooms Late, Extraordinary Auction Sales
2019: A year of ups and downs in the gem and jewelry industry, including diamonds, retail, auction sales and laboratory-grown diamonds.
Gemstones in the Era of the Taj Mahal and the Mughals
A look at the gem ornamentation of this landmark, as well as the jewels of the Mughal dynasty.
Wollastonite in Devitrified Glass Imitating Horsetail Inclusions in Demantoid Garnet
A yellowish green specimen with horsetail-like inclusions is found to be glass rather than demantoid garnet.
Star Spinel with Four and Six Rays
A cabochon displaying asterism is found to be an untreated spinel with two different stars.