The Carlsbad lab received a rhodochrosite cabochon featuring rhomboid-shaped fluid inclusions, causing a four-rayed star.

Unique diamond- and emerald-lensed spectacles from the Mughal Empire were tested in GIA’s New York laboratory.

The first installment of this column discusses the formation of colored stones from the crust-mantle transition and below.

Researchers examine six specimens of banded turquoise, obtained through long-term cooperation of local miners in Zhushan County.

A gemological analysis of blue Burmese sapphires from Mogok, based on a series of field expeditions over the last decade.

The Carlsbad lab recently encountered a 2.42 ct green diamond showing signs of radiation treatment by the use of radioactive salts.

The Bangkok lab recently encountered a single round crystal of chondrodite in red spinel, a possible indicator of Burmese origin.

An overview of the Winter 2021 Gems & Gemology content.

GIA’s New York laboratory reports a new record size for CVD laboratory-grown diamond.

CARLSBAD, Calif. – Dec. 2, 2021 – The joy diamonds bring to people’s lives and the confidence inspired by a diamond grading report from the experts at GIA are at the center of GIA’s first new global consumer marketing campaign in more than a decade.

CARLSBAD, Calif. – Dec. 2, 2021 – The joy diamonds bring to people’s lives and the confidence inspired by a diamond grading report from the experts at GIA are at the center of GIA’s first new global consumer marketing campaign in more than a decade.

CARLSBAD, Calif. – Nov. 17, 2021 – The GIA Board of Governors held their first in-person meeting in two years, Nov. 5 – 8, in Carlsbad, California.

Distinguished research fellow Dr. James Shigley receives the Robert M. Shipley Award for his contribution to the science of gemology.

Although spinel is rarely treated, there have been some heated spinels available in the trade.

Recently, a 23.67 ct pear cabochon aquamarine with light greenish blue color and poor clarity was sent to the Taiwan Union Lab of Gem Research (TULAB) for identification.

A study on heat with pressure treatment of blue sapphires reveals FTIR patterns associated with different iron concentrations.

A colorless topaz from Nigeria hosts the only known example of willemite as an inclusion in topaz.

The Tokyo lab examined a stunning double cat’s-eye emerald whose chatoyancy was created both by its cut and its inclusions.

A group of large, high-quality CVD material demonstrates the continued challenge of identifying laboratory-grown gems.

Creative faceting highlights an octahedral-shaped cloud inclusion in a 2.01 ct diamond octahedron.