Summer 2024 G&G Available Now
August 2, 2024
The Summer issue of Gems & Gemology has a wide range of topics in store, from a GIA update on laboratory-grown diamonds to the characterization of anorthoclase feldspar from southeast Vietnam and cassiterite from China. In addition to the three feature articles and our regular sections, this installment includes the return of the Colored Stones Unearthed column, a new inclusions wall chart, and an in-depth look at painted labradorite artwork.
LABORATORY-GROWN DIAMONDS: AN UPDATE ON IDENTIFICATION AND PRODUCTS EVALUATED AT GIA
Dr. Sally Eaton-Magaña and fellow GIA researchers provide an update on the advancements and major trends in laboratory-grown diamonds observed by GIA since 2007. Following a summary of the two diamond growth processes (HPHT and CVD), the article discusses the methods and strategies for identifying laboratory-grown diamonds using gemological characteristics and advanced testing approaches.
GEMOLOGICAL AND TRACE ELEMENT CHARACTERISTICS OF CASSITERITE FROM YUNLING, CHINA
Dr. Wenqing Huang and coauthors examine gem-quality cassiterite from the Yunling area of southwest China, summarizing its gemological characteristics, internal features, and absorption spectra. Trace element chemistry among the seven color groups is analyzed to distinguish the cassiterite from a Bolivian source.
GEM-QUALITY ANORTHOCLASE FELDSPAR FROM SOUTHEAST VIETNAM
A team led by Le Ngoc Nang reports on an anorthoclase variety of gem-quality feldspar originating from Cenozoic alkali basalt in southeast Vietnam. Their study of yellow, brownish gray, and near-colorless samples evaluates the potential for commercial use.
MICRO-FEATURES OF TOURMALINE
Nathan Renfro, John Koivula, and coauthors add to the G&G series of micro-feature charts with this display of inclusions found in tourmaline, as well as tourmaline inclusions in other hosts. The wall chart, which presents 30 superb photomicrographs, is included in every printed copy of this issue, and a laminated version is available for sale in the GIA store.
LAB NOTES
GIA’s global laboratory staff present their latest findings in the Lab Notes section, including asteriated cloud inclusions in natural diamond, a rare chatoyant hexagonite, and a large multicolored natural blister pearl.
MICRO-WORLD
The Micro-World section, dedicated to the inner world of gemstones, features a square-shaped cloud in diamond, a twelve-rayed double-star phenomenon in ruby, and a group of fingerprint and crystal inclusions that form a unique shape in a Montana sapphire.
COLORED STONES UNEARTHED
The Colored Stones Unearthed column returns in this issue, covering the synthesis of gem materials and the unique growth conditions that can help separate them from natural gems.
GEM NEWS INTERNATIONAL
The GNI section includes various reports from contributors worldwide, such as new emerald production in Western Australia, an abnormally large flux-grown synthetic sapphire, and an inside look at the Clarity Diamond facility in Austin, Texas.
IN THE SPOTLIGHT
Lastly, we highlight the work of artist Valentina Fetisova, who transforms labradorite cabochons into painted scenes from the natural world, using the labradorescence effect to enhance her creations.
Erica Zaidman is associate editor of Gems & Gemology at GIA in Carlsbad, California.
