Large near colorless, blue, and yellow diamonds broke auction records at Christie’s and Sotheby’s in the first half of 2022.

Both asterism and chatoyancy are observed in a color-change sapphire.

An examination of 45 gems from the coronation crown of Napoleon III, using nondestructive mobile spectroscopic and gemological testing methods.

Discusses the unusual surface characteristics of ekanite from secondary deposits in Sri Lanka.

Uses gamma-ray spectrometry to directly measure internal radioactivity in green nephrite from deposits in Poland, Russia, Canada, and New Zealand.

Offers the first detailed summary of amber from the Vietnamese island of Phu Quoc and a comparison with Baltic, Dominican, and Burmese material.

Reports on diamonds from Guyana’s alluvial deposits, including mining history and practices.

A fascinating diamond crystal inclusion displaying a transparent, ghost-like appearance is identified in a Faint green diamond.

A lab in Bangkok shares study on color stability in yellow sapphire.

Numerous etch channels are observed in a 5.19 ct type IIa natural diamond.

A unique jade cabochon with vivid green bodycolor and pronounced chatoyancy is examined at a lab in Shanghai.

Two impressive diamonds from Arkansas and Colorado are featured in the Great American Diamonds exhibit at the Smithsonian’s National Museum of Natural History.

The historic discovery of a Maine tourmaline source is celebrated through jewelry designs featuring gems unearthed 50 years ago.

GIA’s New York laboratory reports on a 15.10 ct Fancy Vivid blue cut-cornered rectangular step cut named the De Beers Cullinan Blue diamond.

This installment of “Colored Stones Unearthed” explores inclusions in gems—how they form, how they are studied, and what they mean for gemologists and geoscientists.

A glimpse at the rare gems recently on display at the Natural History Museum of Los Angeles County’s Brilliance: The Art and Science of Rare Jewels exhibit.