About the Cover... This issue features a chart of tourmaline inclusions. Shown on the cover is a 20 × 16 cm carving by Patrick Dreher and Daniella Becker containing rubellite strawberries and green tourmaline leaves. Jürgen Christmann completed the quartz vase, and Eckhard Cullmann was the goldsmith. The rubellites are from the Himalaya mine in San Diego County, California, and the green tourmalines are Brazilian. Photo by Robert Weldon; courtesy of Pala International.

Happy Anniversary: Summer Reading: GIA’s Gems & Gemology Summer Issue – G&G at 90!

It is Gems & Gemology’s (G&G) 90th year, and the Summer 2024 issue features an update on lab grown (synthetic) diamonds, micro features in tourmalines, cassiterite from China, and feldspars from Vietnam, along with all of the noteworthy Gem Notes.

Since its inception in January 1934, G&G has been dedicated to providing the jewelry trade with accurate and up-to-date information about gemstones. This summer issue is no exception, bringing you the latest advancements in gemological research, with a focus on scientific techniques and instrumentation that are transforming the field.

Feature articles include:

Laboratory-Grown Diamonds: An Update on Identification and Products Evaluated at GIA
Sally Eaton-Magaña, Matthew F. Hardman, and Shoko Odake
Reviews the latest advancements and trends in laboratory-grown diamonds observed by GIA since 2007, highlighting significant developments in identification techniques.

Figure 1. This 10.02 ct E-color, VS1-clarity emerald-cut diamond is an example of the great strides made in HPHT growth technology in the past two decades, as laboratory-grown diamonds have become an important sector of the gem diamond market. Photo by Johnny Leung. The as-grown CVD diamond plate (1.24 ct, 8.41 × 8.60 × 1.26 mm) was manufactured by GIA at its New Jersey research facility. Photo by Adrian Chan.

Gemological and Trace Element Characteristics of Cassiterite from Yunling, China
Wenqing Huang, Jungui Zhou, Ting Shui, Junyi Pan, Fanwei Meng, Rui Zuo, Shuxin Dong, and Suqiao Cao
Examines gem-quality cassiterite from southwest China, providing an in-depth analysis of its trace element chemistry to distinguish it from Bolivian cassiterite.

Figure 10. Internal features of Yunling cassiterite: an elongated tourmaline crystal in sample C-G8 (A) and clusters of tourmaline inclusions in samples C-G17 (B) and C-G16 (C and D). Photomicrographs by Wenqing Huang; fields of view 1.23 mm (A–C) and 0.6 mm (D).

Gem-Quality Anorthoclase Feldspar from Southeast Vietnam
Le Ngoc Nang, Pham Minh Tien, Pham Minh, and Pham Trung Hieu
Characterizes an anorthoclase variety of alkali feldspar from southeast Vietnam, evaluating its potential for commercial use in the gem market.

Figure 3. Nodules of anorthoclase were discovered in massive basalt by the lead author in sizes up to 22 cm (A), 6 cm in vesicular basalt (B), and 4 cm as fragments in alluvial deposits (C). Photos by Pham Minh Tien.

Micro-Features of Tourmaline
Nathan Renfro, Tyler Smith, John I. Koivula, Shane F. McClure, and James E. Shigley
A comprehensive visual guide to the internal features of tourmaline, showcasing the diversity and complexity of this popular gemstone.

A slice of elbaite tourmaline from Brazil shows complex color zoning when viewed perpendicular to the c-axis of the crystal. Field of view 13.43 mm.

G&G’s regular features include:

Tap here to read GIA’s Summer 2024 Issue of Gems & Gemology!

And tap here to download your own digital copy!

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