Examination of a faceted rock crystal backed by a slice of turquoise—an obvious but unusual combination of gem materials.

A summary of the article “A simple approach to separate natural from synthetic ametrine,” by Francine Payette.

Synthesized gem-quality diamonds from the General Electric Company are analyzed for characteristics that distinguish them from natural stones.

This article reports on a detailed gemological examination of this new synthetic cat's-eye alexandrite.

A find of new gem garnets has been made in contact metamorphic deposits in the Republic of Mali, western Africa.

Observations made at GIA on 858 GE-processed diamonds revealed several interesting features that may be diagnostic of this kind of diamond. Specifically, a significant percentage exhibited a slightly hazy appearance, noticeable internal graining, and other unusual internal features.

A natural diamond contains two inclusions resembling a faceted diamond and a rough diamond.

Aragonite and calcite create a captivating iridescent effect in a Pinnidae shell.

A sample of yellow sphene displays a cloud of soap bubble–like inclusions with interference colors.

The author has uncovered many ancient references to the simulation or enhancement of gemstones.

With the withdrawal of Soviet troops from Afghanistan, villagers in the Panjshir Valley are turning their attention to the emerald riches of the nearby Hindu Kush Mountains.

The Anahí mine, Bolivia, has produced large amounts of amethyst, citrine, and amethyst-citrine for the gem market.

The Argyle diamond mine is the only known source of type IaB hydrogen- and nitrogen-rich diamonds colored gray to blue to violet.

Vietnamese aquamarine is notable for its attractive color and well-formed crystals.

Over the past several years, diamond simulants have entered the market that consisted of colorless cubic zirconia reportedly coated with a thin layer (e.g., represented to be 30–50 nm) of nanocrystalline diamond particles embedded in a matrix.

Gem Testing lab in Jaipur, India recently examined a white-brown, translucent to opaque oval cabochon that turned out to be a composite featuring an unusual combination of gem materials.

The most important source of yellow gem elbaite is the Canary mining area in the Lundazi District of eastern Zambia.

An review of the Oregon sunstone seen at the Tucson gem shows.

A look at JTV’s history, current activities, and impact on the industry.