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

An overview of the Winter 2021 Gems & Gemology content.

Contributes to the mining history of Austria’s Habachtal region, which is believed to be one of the earliest emerald deposits.

加利福尼亚州卡尔斯巴德 – 12 月 16 日（星期四） – 作为宝石学研究、教育以及以科学为基础的宝石鉴定与分级服务领导者，GIA（美国宝石研究院）目前正在大力发展其卓越的服务体系和员工队伍，致力于向全球主要品牌和零售商提供创新产品。

加利福尼亚州卡尔斯巴德 – 2021 年 12 月 2 日 – 给人们的生活带来喜悦的钻石以及 GIA 的钻石分级专家报告所激发的信心是 GIA 十多年来首次全球消费者营销活动的核心。

加利福尼亚州卡尔斯巴德 – 2021 年 12 月 2 日 – 给人们的生活带来喜悦的钻石以及 GIA 的钻石分级专家报告所激发的信心是 GIA 十多年来首次全球消费者营销活动的核心。

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.

Careful comparison of two GIA reports reveals a fraudulent inscription on a laboratory-produced diamond presented as a natural.

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.

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.

Reports on the geology, background, and current state of mining and production at Iran’s largest turquoise mine.

Figure 1. The vivid colors seen in fine gem-quality spinel are derived from the mixing between multiple different chromophores in a range of ratios and concentrations, as in this fine 13.52 ct violetish purple spinel. Courtesy of the Dr. Edward J. Gübelin Collection. Photo by Robert Weldon/GIA.

A selection of 74 non-bead cultured and 12 bead cultured pearls grown in cultured pearl sacs and harvested directly from operated mollusks were collected and their internal structures examined using real-time microradiography and X-ray computed microtomography analyses.