The authors examine the gemological properties and commercial potential of a new source of amber, discovered in 2020 on the Vietnamese island of Phu Quoc. It is the only known amber locality in ...

The spinel exhibited was reportedly mined in Makoko, a village in the southern part of the country. According to Smith, the early findings from this location were small and very poor in quality, until ...

Many unusually large South Sea cultured pearls have been identified at GIA laboratories in the past (e.g., Fall 2013 Lab Notes, pp. 172–173; Summer 2023 Lab Notes, pp. 216–217). However, a recent ...

At the GJX show, Pillar & Stone (San Francisco, California) offered bright green jade from Guatemala, confirmed to range from jadeite to omphacite, that was highly translucent to nearly transparent.

GIA’s Bangkok laboratory received for identification a set of 35 loose non-nacreous pearls displaying a wide range of bodycolors including white, orange, pink, brown, purple, and black. The pearls ...

In general, 2025 was a strong year for Tucson vendors at the various shows. Like last year, foot traffic was generally low with moments of high activity, while buying remained focused. Vendors who ...

Figure 2. Representative deep-UV fluorescence image of a 2.90 ct CVD diamond from Plasmability, collected using the DiamondView. The image is dominated by red–orange fluorescence from NV 0 centers, a ...

About GIA An independent nonprofit organization, GIA (Gemological Institute of America), established in 1931, is recognized as the world’s foremost authority in gemology. GIA invented the famous 4Cs ...

A remarkable large calcite recently seen at the GJX show displayed a dazzling array of colors resulting from both high dispersion and birefringence (C.S. Hurlbut and C.A. Francis, “ An extraordinary ...

In the jewelry world, innovation continuously drives the industry forward, with jewelry designers often at the forefront of the creative attempt. The author found two bangles exemplifying this ...

You’re in for a delectable treat with our Spring 2025 issue of Gems & Gemology! We cover detecting heated corundum, the rare and remarkable Winston Red diamond, and an extraordinary Renaissance jewel ...

GIAについて 1931年設立の独立非営利組織であるGIA（Gemological Institute of America）は、宝石学における世界有数の権威として認められています。GIAはカラー、クラリティ、カット、カラット ウェイトからなる有名な4Cを考案し、さらに1953年にはダイヤモンドの品質の基準として世界中で認知されて ...