The latest Issue of 2024 of The Journal of Gemmology (Volume 39, No. 4), published by Gem-A in collaboration with SSEF, features a series of studies focused on specific aspects of gemmology. Among the topics covered are gemstone characterization, the analysis of non-nacreous pearls, and the examination of inclusions in sapphires.
The article “Tourmaline from the Governador Valadares and Araçuaí Mining Regions, Minas Gerais, Brazil” describes the analysis of 83 tourmaline samples from the mining regions of Governador Valadares and Araçuaí, in the state of Minas Gerais (Brazil). The authors — Dietmar Schwarz, Lynn Li, Yifang Chen, Zhengyu Zhou, Yenruedee Lhongsomboon, and Constantino (Dino) Psomopoulos — illustrate the gemmological characteristics of the samples, including observations of inclusions such as albite, lepidolite/muscovite, and condrodite, while providing an overview of the chromatic variation observed among the analyzed samples.
The article “Surface Features and Internal Structures of Non-nacreous Pearls from Pinctada maxima” by Jayesh Surve, Abeer Al-Alawi, and Chunhui Zhou, analyzes the surface characteristics and growth structures of non-nacreous pearls, presumably obtained from the mollusk Pinctada maxima. The study helps clarify certain aspects related to the classification and identification of this rare type of pearl in jewelry.
The article “Nano-inclusions Associated with Beryllium in Untreated Blue Sapphires from Diego Suarez, Madagascar” by Kentaro Emori, Seika Oto, Yohei Igami, Jun Uzuhashi, Tadakatsu Ohkubo, Hiroshi Kitawaki, and Akira Miyake examines the presence of beryl associated with specific inclusions in untreated blue sapphires from Diego Suarez (Antsiranana, Madagascar). The study distinguishes two types of inclusions and analyzes their implications for stone identification.
In addition to the main articles, this issue includes short in-depht such as Namibian blue chalcedony, Ethiopian emeralds, spinels, specific cases of diamonds, and an update on the DiaTrue Coda, a tool for the separation of natural and synthetic diamonds.
Issue no. 4, Vol. 39, is available on the website of The Journal of Gemmology. The first issue of 2025 (no. 5, Vol. 39), is also available.
