Although the Pinctada margaritifera oyster usually is associated with the black pearls cultured in French Polynesia, it also can produce attractive large yellow cultured pearls, among other colors.

This article presents the first complete gemological characterization of the historic 128.48 ct Brazilian diamond known as the Star of the South.

Liddicoatite, a calcium-rich lithium tourmaline, was recognized as a separate mineral species in 1977, and named in honor of Richard T. Liddicoat.

Buying gems or jewelry can be challenging even when one has access to a fully equipped lab.

On this occasion—the celebration of Richard T. Liddicoat’s 50 years guiding Gems & Gemology—it is fitting to review his enormous impact on the field of gemology.

Jewelry designer Paula Crevoshay showcases the work of some of North America’s leading lapidaries.

For most of the 20th century, the principal source of fine spessartine was the area around the Little Three mine near the town of Ramona in southern California.

Vivid blue, green, and purple-to-violet cuprian elbaites, renowned in the gem trade as “Paraíba” tourmalines, continue to be recovered in small amounts from northeastern Brazil.

The submission of a large (4.54 ct) jeremejevite of an unusual—yellow—color to the AGTA Gemological Testing Center prompted a search of the available gemological literature.

This second major article in a three-dimensional modeling study analyzes fire – the visible extent of light dispersed into spectral colors.

Several gems were recently examined that showed stars with an unnatural appearance or an unusual number of rays.

A comparison study was made between the yellow and white nacre of the gold-lipped Pinctada maxima oyster shell and 65 yellow cultured pearls.

Chinese freshwater cultured pearls (FWCPs) are assuming a growing role at major gem and jewelry fairs, and in the market at large.

Australia’s Argyle mine has set records for volume since its establishment in 1983, and is additionally noted for its rare pink diamonds.

Ammolite is a form of aragonite that is obtained from vivid iridescent fossilized ammonite shells mined in Alberta, Canada.

Gemstone enhancements and their disclosure became the most important gemological issue for the jewelry trade in the 1990s.

The 1990s saw growth in gem exploration, production, and marketing worldwide.

Haüyne is a rare mineral and an extremely rare gemstone.

Two archeological sites that were discovered recently on the island of Antigua appear to have had flourishing lapidary industries.

Since 1996, large quantities of yellow to blue sapphires have been recovered from alluvial deposits derived from basaltic rocks in northern Madagascar.