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

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.

Unique natural etch pattern and dissolution cavities are observed in a large aquamarine crystal.

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

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.

An overview of the Summer 2022 Gems & Gemology content.

The first report of a topaz inclusion in rare red beryl from Utah.

An extremely convincing imitation of emerald is examined in Beijing.

Photochromic zircon shows significant color change from medium light greenish blue to very dark yellowish green.

A unique twinned crystal inclusion resembles a boomerang in a rough topaz.

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.

Rare optical phenomenon observed in four star quartz cabochons from Brazil.

GIA, the leader in gemological research, education and science-based gem identification and grading services, is expanding its gem origin services to provide retailers and consumers with the diamond source information they demand.

GIA welcomes Johanna Levy as the Institute’s first vice president of environmental, social and governance (ESG) programs.

GIA, the leader in gemological research, education and science-based gem identification and grading services, is expanding its gem origin services to provide retailers and consumers with the diamond source information they demand.

A 3.03 ct stone submitted to GIA’s Bangkok laboratory was identified as a ruby from Mozambique with no indication of heating.

A very light blue hexagonal apatite inclusion is observed in natural smoky quartz.