The Spring 2026 issue of G&G is packed with new content. Along with our regular sections, we highlight natural green diamonds, the interiors of South Sea “Keshi” pearls, and a seventeenth-century Armenian gem trader in our feature articles.
A CLASSIFICATION SCHEME OF NATURAL RADIATION STAIN MORPHOLOGY AND TEXTURE ON DIAMOND
Taryn Linzmeyer and fellow researchers contribute a much-needed study of natural green diamonds to the gemological literature. They provide a visual catalog of radiation stain morphology and textural characteristics of 84 naturally irradiated diamonds, classifying these fascinating features by color, opacity, shape, and surface texture.
DIVERSE RANGE OF ORGANIC-RICH CORES IN SOUTH SEA NON-BEAD CULTURED “KESHI” PEARLS
Nishka Vaz and coauthors present a paper on the non-bead cultured pearls the trade calls South Sea “keshi,” which can be hard to distinguish from natural pearls. To help provide separation criteria, the authors examined the structure of 43 pearls with organic-rich concentric cores using real-time X-ray microradiography, computed microtomography, and energy-dispersive X-ray fluorescence chemical analysis.
RECORDS FROM A LUXURIOUS PAST: GEM INVENTORY OF A SEVENTEENTH-CENTURY ARMENIAN MERCHANT
Dr. Sona Tajiryan provides insight into the extensive gem collection of prominent seventeenth-century Armenian gem merchant Gregorio di Girach-Mirman using a previously unexamined probate document. The study underscores the value of historical documents, which illuminate transcontinental trading routes, merchandising strategies, and practices of early modern gem traders.
LAB NOTES
GIA’s global laboratory staff present their latest findings in the Lab Notes section, including a natural rough diamond treated to a vibrant purple color, a rough Ethiopian opal bearing a striking resemblance to a chocolate bar, and a rare transparent red-brown staurolite.
MICRO-WORLD
Micro-World reveals wonders inside gems: goethite sprays in apatite, play-of-color on the surface of a pen pearl, a “mystery bubble” in spinel, a remarkable pristine moldavite from the Czech Republic, and more.
GEM NEWS INTERNATIONAL
Worldwide Gem News International contributors share new chrysoprase production from Western Australia, a multinational jewelry retailer’s initiative to provide meals to children in need, and a CVD-grown diamond artfully shaped to imitate a rough natural gem.
IN THE SPOTLIGHT
In the Spotlight explores a fabulous exhibit of Cartier jewels at the Palazzo Nuovo of the Capitoline Museums in Rome.
The Spring 2026 issue of G&G is packed with new content. Along with our regular sections, we highlight natural green diamonds, the interiors of South Sea “Keshi” pearls, and a seventeenth-century Armenian gem trader in our feature articles.
A CLASSIFICATION SCHEME OF NATURAL RADIATION STAIN MORPHOLOGY AND TEXTURE ON DIAMOND
Taryn Linzmeyer and fellow researchers contribute a much-needed study of natural green diamonds to the gemological literature. They provide a visual catalog of radiation stain morphology and textural characteristics of 84 naturally irradiated diamonds, classifying these fascinating features by color, opacity, shape, and surface texture.
DIVERSE RANGE OF ORGANIC-RICH CORES IN SOUTH SEA NON-BEAD CULTURED “KESHI” PEARLS
Nishka Vaz and coauthors present a paper on the non-bead cultured pearls the trade calls South Sea “keshi,” which can be hard to distinguish from natural pearls. To help provide separation criteria, the authors examined the structure of 43 pearls with organic-rich concentric cores using real-time X-ray microradiography, computed microtomography, and energy-dispersive X-ray fluorescence chemical analysis.
RECORDS FROM A LUXURIOUS PAST: GEM INVENTORY OF A SEVENTEENTH-CENTURY ARMENIAN MERCHANT
Dr. Sona Tajiryan provides insight into the extensive gem collection of prominent seventeenth-century Armenian gem merchant Gregorio di Girach-Mirman using a previously unexamined probate document. The study underscores the value of historical documents, which illuminate transcontinental trading routes, merchandising strategies, and practices of early modern gem traders.
LAB NOTES
GIA’s global laboratory staff present their latest findings in the Lab Notes section, including a natural rough diamond treated to a vibrant purple color, a rough Ethiopian opal bearing a striking resemblance to a chocolate bar, and a rare transparent red-brown staurolite.
MICRO-WORLD
Micro-World reveals wonders inside gems: goethite sprays in apatite, play-of-color on the surface of a pen pearl, a “mystery bubble” in spinel, a remarkable pristine moldavite from the Czech Republic, and more.
GEM NEWS INTERNATIONAL
Worldwide Gem News International contributors share new chrysoprase production from Western Australia, a multinational jewelry retailer’s initiative to provide meals to children in need, and a CVD-grown diamond artfully shaped to imitate a rough natural gem.
IN THE SPOTLIGHT
In the Spotlight explores a fabulous exhibit of Cartier jewels at the Palazzo Nuovo of the Capitoline Museums in Rome.
