Examination of a gigantic South Sea bead cultured pearl reveals an intriguing internal structure.

Investigates the correlations between peak positions in the 3309 cm–1 series with trace element concentrations for ruby, metamorphic and basalt-related blue sapphire, and laboratory-grown sapphire.

A highly saturated purplish pink to red pezzottaite from a new deposit in Madagascar is encountered in Tucson and tested by GIA researchers.

Archival research and gemological characterization reveal the geographic origin of two emeralds set in a pendant linked to Catherine de’ Medici, Queen of France from 1547 to 1559.

Presents the first scientific and historical study conducted on the 2.33 ct Winston Red, the fifth-largest known Fancy red diamond in existence.

A look at the most popular phenomenal gems exhibited at the 2025 Tucson gem shows.

A black opal cabochon set in a ring displays vivid orange play-of-color.

A summary of the findings at the 2025 Tucson gem shows.

Uniquely saturated examples of the collector stone were on display at GJX.

Beginning later this year, GIA will start using descriptive terms to characterize the quality of laboratory-grown diamonds

Beginning later this year, GIA will start using descriptive terms to characterize the quality of laboratory-grown diamonds.

Learn about the principles, mechanisms, and characteristics of luminescence that create the impressive and memorable glow of gemstones.