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

Characterizes an anorthoclase variety of alkali feldspar found in southeast Vietnam and evaluates its potential for commercial use.

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 ...

An orangy pink morganite specimen from Madagascar contains hundreds of yellow helvine crystals aligned on a single plane.

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 ...

Lab Notes Gems & Gemology, Spring 2024, Vol. 60, No. 1 Pearls from the Placunidae Family (Windowpane Oysters) Joyce Wing Yan Ho, Kwanreun Lawanwong, and Artitaya Homkrajae ...

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, ...

Learn the latest on Madagascar sapphires and demantoid garnets from Wim Vertriest, GIA Manager of Field Gemology.

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.

Explores eclogitic diamonds, which make up a significant portion of the gem diamond market, and what they reveal about Earth’s dynamic processes.

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