(Press Release) The fall 2016 issue of Gems & Gemology (G&G), GIA’s quarterly professional journal, covers synthetic diamonds grown by the chemical vapor deposition (CVD) process, a reversible color modification of zircon and a rich vein of locality articles. The issue, which is now available in print and online, takes readers on a journey to a new deposit of blue to pinkish blue sapphire in the Russian Far East, a new deposit of the rare gem grandidierite in Madagascar, a peridot source in Vietnam’s Central Highlands and a pearl farm in the waters off the Indonesian island of Lombok.
G&G’s lead story “Observations on CVD-Grown Synthetic Diamonds: A Review” presents a comprehensive summary of the volume and quality of CVD diamonds from their “precommercial” phase prior to 2008, to the range and color of material available today. The authors, GIA’s Dr. James Shigley and Dr. Sally Eaton-Magaña, review the characteristics and key identifying features of CVD synthetic diamonds based on the study of several hundred faceted examples examined by GIA between 2003 and 2016. In the second feature article, GIA researcher Nathan Renfro uses spectroscopy to confirm whether exposure to visible light might restore blue zircons inadvertently altered to unattractive brown through accidental exposure to long-wave ultraviolet radiation from tanning beds or other UV lights.
Next, a team of Russian researchers led by Svetlana Yuryevna Buravleva of the Far East Geological Institute, Far Eastern Branch of the Russian Academy of Sciences in Vladivostok studies the formation and chemical composition of the largely unexamined alluvial sapphires from Russia’s Jewish Autonomous District. In the fourth article, lead author Dr. Delphine Bruyère from the French Geological Survey in Orléans reports on a new occurrence of the rare gem grandidierite in southern Madagascar, which occurs as bluish green to greenish blue crystals measuring up to 15 centimeters in length and is some of the purest grandidierite found to date.
In the issue’s fifth paper, the Hanoi University of Science’s Dr. Nguyen Thi Minh Thuyet and colleagues review the gemological and geochemical characteristics of peridot from Vietnam’s Central Highlands. In the final article, a team of researchers led by GIA’s Nicholas Sturman recover bead-cultured and non-bead-cultured pearls from gold-lipped oysters at a pearl farm in the pristine waters off the Indonesian island of Lombok.
The issue also features G&G’s regular Lab Notes and Gem News International sections, which include informative entries from contributors around the world, as well as the G&G Micro-World column, which features descriptions and photomicrographs of remarkable inclusions.
G&G’s free archive containing every issue from 1934 to present, more in-depth coverage, hundreds of additional photos, and exclusive video footage are available on GIA’s website at www.gia.edu/gems-gemology.