Application of slight pressure perpendicular to the twinning planes reveals the unusual property of this synthetic gem.

Conspicuous bright brownish red crystals in ruby matrix are the first recorded observations of staurolite in corundum.

Chronicles developments at the Chivor emerald mine in Colombia between 1880 and 1925, based on archival records.

Presents a quantitative means of determining the causes of color in a gem material, using corundum’s six major chromophores as an illustration.

Investigates the chemical, physical, and gemological properties of attractive rhodonite-rich rocks from this Swiss deposit.

Discusses the features of alkali elements and their influence on the color of blue to yellow beryl.

Explores the art form of jade carving in China across five periods from the late Neolithic Age to the present day.

A freely moving diamond crystal completely enclosed in a diamond from Siberia gets its name from the famous Russian nesting dolls.

Diamond inclusions are relatively common guests in diamond crystals.

GIA’s Hong Kong laboratory looks at a new radio-frequency identification (RFID) technology for tracking cultured pearls.

A Japanese television documentary series spotlights the global fascination with gems and jewelry by visiting various physical and cultural sites around the world.

Two fascinating fossilized blister pearl specimens possibly 86 million years old reveal insights into ancient mollusks.

Green nephrite deposits are found at many locations around the globe, with British Columbia, Siberia, and northwestern China as the leading producers.

Mina Stones promotes Nigerian gems including rubellite and sapphire as well as reviving traditional skills and symbols in the creation of original jewelry.

Untreated Russian emeralds, rarely seen in the market, demonstrate a range of color and degree of fineness.

Advanced analytic techniques are critical for separating Ethiopian feldspar from Oregonian and copper-bearing feldspar with undetermined color origin.

A delicate, ethereal necklace depicting a diamond butterfly caught in a gem-studded spider’s web won the third annual Gianmaria Buccellati Foundation student jewelry design contest.

The unusual six-rayed trapiche pattern, identified mainly with Muzo emeralds, has also been discovered in Mogok sapphires and Mong Hsu rubies.

In early February, despite the early phase of the COVID-19 outbreak, the Tucson shows were well attended and sales were brisk.

A rare Burmese star peridot cabochon is characterized by a soft four-rayed asterism and extremely fine acicular inclusions.