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

ABSTRACT Pizzo Tremogge in Val Malenco, Italy, is a source of gem-quality serpentine. Samples from this mountain locality were investigated by standard gemological and petrological methods, Raman ...

CARLSBAD, Calif. – June 2, 2025 – Beginning later this year, GIA (the Gemological Institute of America) will start using descriptive terms to characterize the quality of laboratory-grown diamonds and ...

Diamonds have a long history as a premier gemstone—a natural consequence of their beauty, rarity, and superlative physical properties such as extreme hardness. Diamonds that are mined for use as ...

Provides a visual guide to the internal features of tourmaline as well as tourmaline inclusions in other gem hosts.

The micro-world of gems lies at the very core of gemology. Information gathered from observations through the microscope serves as the very foundation for many conclusions drawn on a specimen, ...

A wide range of Guatemalan jadeite jade in blue, green, and lavender hues was offered at the 22nd Street show in Tucson.

An Arkansas lapidarist shares his work with wavellite and explains his stabilization process.

The quality and size of this 4.04 ct CVD-grown diamond ring demonstrate the advancing technology in laboratory-grown diamonds.

Prismatic blue and colorless dumortierite inclusions in rock crystal quartz are examined for the first time in the Carlsbad lab.

GIA researchers report on a new nickel-diffusion treatment used to modify color in spinel and present criteria for identification.

This installment of “Colored Stones Unearthed” explores inclusions in gems—how they form, how they are studied, and what they mean for gemologists and geoscientists.