Heat treatment leaves a stunning circular stress fracture in amber.

A tapered baguette-cut diamond exhibits two major color zones.

Provides a visual guide to the internal features of different varieties of beryl.

Reports on the recent production of precious and common opal from a centuries-old locality.

Explores the formation of sedimentary rocks, gems found and formed in sedimentary environments, and the alluvial mining of these gems.

An overview of the Winter 2023 Gems & Gemology content.

Documents the gemological properties, chemical composition, and appearance of petrified tree fern discovered in northeast China.

A comprehensive look at Texas topaz, detailing its gemological and compositional characteristics and providing a basis for using trace element concentrations to identify its origin.

GIA’s Mumbai laboratory analyzes seed pearls decorating an Indian-style headdress.

Investigation of a tubular feature in a natural pearl reveals evidence of parasitic activity.

A crystal inclusion with a stress halo resembles a colorful butterfly in a 1.01 ct diamond.

A large Pinctada radiata natural blister pearl displays a unique reaction under long-wave ultraviolet light.

A rare octahedral gahnospinel crystal is observed in Sri Lankan sapphire.

An overview of the Winter 2023 Gems & Gemology content.

Examines a technique for setting cut garnets on glass objects, invented by Claudius vom Creutz of Nuremberg in the late sixteenth century.

The GIA New York laboratory is now accepting GIA graded diamonds for the same-day confirmation service that was announced on January 9.

The GIA New York laboratory is now accepting GIA graded diamonds for the same-day confirmation service that was announced on January 9.

GIA 正在採取強有力的行動，以回應關於實驗室製造鑽石切割幾乎與 GIA 分級天然鑽石相匹配的欺詐性 GIA 銘文的報告。

GIA is taking strong action in response to reports of fraudulent GIA inscriptions on laboratory-grown diamonds cut to nearly match GIA graded natural diamonds.