“Diffusion Ruby” Proves to be Synthetic Ruby Overgrowth on Natural Corundum
A relatively new production of red corundum, reportedly from Bangkok, has been offered for sale in recent years.
Characterization and Grading of Natural-Color Pink Diamonds
Known for their great beauty and rarity, pink diamonds have long been sought after by jewelers, collectors, and consumers.
Identification of Yellow Cultured Pearls from the Black-Lipped Oyster Pinctada Margaritifera
Although the Pinctada margaritifera oyster usually is associated with the black pearls cultured in French Polynesia, it also can produce attractive large yellow cultured pearls, among other colors.
Star of the South: A Historic 128 Ct Diamond
This article presents the first complete gemological characterization of the historic 128.48 ct Brazilian diamond known as the Star of the South.
Liddicoatite Tourmaline from Anjanabonoina, Madagascar
Portable Instruments and Tips on Practical Gemology in the Field

The Ultimate Gemologist:A Tribute to Richard T. Liddicoat
On this occasion—the celebration of Richard T. Liddicoat’s 50 years guiding Gems & Gemology—it is fitting to review his enormous impact on the field of gemology.
“Voices of the Earth”: Transcending the Traditional in Lapidary Arts
Jewelry designer Paula Crevoshay showcases the work of some of North America’s leading lapidaries.
Spessartine Garnet from Ramona, San Diego County, California
For most of the 20th century, the principal source of fine spessartine was the area around the Little Three mine near the town of Ramona in southern California.
An Update on “Paraíba” Tourmaline from Brazil
Vivid blue, green, and purple-to-violet cuprian elbaites, renowned in the gem trade as “Paraíba” tourmalines, continue to be recovered in small amounts from northeastern Brazil.
Jeremejevite: A Gemological Update
Modeling the Appearance of the Round Brilliant Cut Diamond: An Analysis of Fire, and More about Brilliance
This second major article in a three-dimensional modeling study analyzes fire – the visible extent of light dispersed into spectral colors.
A New Method for Imitating Asterism
Several gems were recently examined that showed stars with an unnatural appearance or an unusual number of rays.
Spectral Reflectance and Fluorescence Characteristics of Natural-Color and Heat-Treated “Golden” South Sea Cultured Pearls
A comparison study was made between the yellow and white nacre of the gold-lipped Pinctada maxima oyster shell and 65 yellow cultured pearls.
The Current Status of Chinese Freshwater Cultured Pearls
Chinese freshwater cultured pearls (FWCPs) are assuming a growing role at major gem and jewelry fairs, and in the market at large.
澳大利亚阿盖尔钻石矿床的发现与开采 (英语)
Australia’s Argyle mine has set records for volume since its establishment in 1983, and is additionally noted for its rare pink diamonds.
Ammolite: Iridescent Fossilized Ammonite from Southern Alberta, Canada
Gemstone Enhancements and Detection in the 1990s
Gemstone enhancements and their disclosure became the most important gemological issue for the jewelry trade in the 1990s.
Gem Localities of the 1990s
Gem-Quality Haüyne from the Eifel District, Germany
Haüyne is a rare mineral and an extremely rare gemstone.

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