GIA has announced the release of the Fall 2023 Gems & Gemology (G&G) issue. G&G Fall looks at timely topics and contains new global gemological discoveries. The issue investigates the chromophores responsible for the color in yellow sapphire, explains which colors and optical effects are caused by metallic copper inclusions in Oregon sunstone, examines dissolution features of heliodor and green beryl from a Ukrainian pegmatite field, and reports on the geological setting and gemological features of violet-blue gem cordierite from new deposits found in British Columbia.
This and every issue of G&G since 1934 are available at no cost on GIA’s website at GIA.edu/gems-gemology.
Fall 2023 Gems & Gemology feature articles include:
- Yellow Sapphire: Natural, Heat-Treated, Beryllium-Diffused, and Synthetic
John L. Emmett, Ungkhana Atikarnsakul, Jennifer Stone-Sundberg, and Supharart Sangsawong
Investigates the various chromophores responsible for color in four types of yellow sapphire.
- Special Colors and Optical Effects of Oregon Sunstone: Absorption, Scattering, Pleochroism, and Color Zoning
Shiyun Jin, Aaron C. Palke, Nathan D. Renfro, and Ziyin Sun
Details the colors and optical effects caused by metallic copper inclusions in this gem-quality feldspar.
- Etch Pits in Heliodor and Green Beryl from the Volyn Pegmatites, Northwest Ukraine: A Diagnostic Feature
Gerhard Franz, Oleksii A. Vyshnevskyi, Volodymyr M. Khomenko, Peter Lyckberg, and Ulrich Gernert
Examines dissolution features of heliodor and green beryl from a Ukrainian pegmatite field and offers criteria to distinguish them from samples found in other localities.
- Iolite from the Thor-Odin Dome, British Columbia, Canada: Geology, Chemical Composition, Inclusions, and Cause of Chatoyancy
Philippe M. Belley
Reports on the geological setting and gemological properties of violet-blue gem cordierite from new deposits located in British Columbia.
G&G’s regular features include:
- Lab Notes detail recent submissions to GIA’s laboratories, including a 4.04 ct ring fashioned from a single-crystal CVD diamond.
- Micro-World highlights fascinating internal feature observations such as zigzag-patterned fingerprints in blue sapphire.
- Diamond Reflections focuses on diamonds formed within eclogitic mantle host rocks.
- Gem News International includes brief studies of Burmese chameleon amber, Guatemalan omphacite jade, and other gem materials. This feature also covers the recent Turquoise United conference and the Chicago Responsible Jewelry Conference.
Join the conversations on GIA’s Gems & Gemology Facebook group with an online community of more than 35,000 members: facebook.com/groups/giagemsgemology. Additional research articles are available at GIA.edu/gia-news-research.