GIA ensures accurate gemological measurements across its global laboratories through rigorous metrology practices, including systematic instrument calibration, validation from traceable standards, and ...

Field Report Gems & Gemology, Winter 2016, Vol. 52, No. 4 Update on Gemstone Mining in Northern Mozambique Wim Vertriest and Vincent Pardieu ...

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 ...

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 ...

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, ...

GIA Match iD™を使用しても銘刻を簡単に見つけることができない場合は、高倍率の顕微鏡でもう一度見てみることをお勧めします。顕微鏡の反射光を使用すると、銘刻が漂白されているかどうかを簡単に確認できることがあり ...

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.

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

A chemical and spectroscopic comparison of two purple gem spinel samples, one of them the first reported example of a spinel with a saturated purple color caused predominantly by chromium and cobalt.