The GIA laboratory in Ramat Gan, Israel, will end operations by the end of 2024 due to changes in the global diamond industry that resulted in significant declines in submissions from local clients ...

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 ...

On January 24th 2024, Wim Vertriest, GIA Manager of Field Gemology, gave GIA’s first student lecture of the year at the GIA World Headquarters in Carlsbad, California. In this lecture, Wim explored ...

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

Presents a method for accurately predicting the color of a gem material when viewed in any direction as long as the polarized spectra and the viewing angle relative to the c-axis are known.

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

Analyzes a group of 23 freshwater “Edison” pearls (a trade name referring to near-round freshwater cultured pearls, usually shell bead cultured) using various gemological and advanced instrumental ...

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.

New York laboratory receives resubmission of HPHT-treated diamond that changed from a dark yellowish brown to a deep yellow-orange during treatment.

2021年Gianmaria Buccellati財団 最優秀ジュエリーデザイン賞を受賞したデザイン。カリフォルニア州カールスバッドでGIAジュエリー デザイン コースを修了したMeghan Simmonsによる作品。このスケッチでは、ゴールドやダイヤモンド ...

A web-like fingerprint creates a maze-like pattern in this spinel from Vietnam, observed with darkfield and diffuse fiber-optic illumination. Photomicrograph by E. Billie Hughes; field of view 5 mm.