Fall 2022 G&G Available Now
November 11, 2022
Get ready to uncover a wide range of topics in the Fall issue, from the challenges of determining the geographic origin of diamond to the use of gem materials as pigments in works of art. In addition to the four feature articles and our quarterly sections, we see the return of Diamond Reflections and the 2022 Gems & Gemology Challenge results.
METHODS AND CHALLENGES OF ESTABLISHING THE GEOGRAPHIC ORIGIN OF DIAMONDS
Diamond origin is a trending topic among consumers and the trade, as consumers seek to know the origin and the impact of purchased goods. The mounting push toward global sustainability has prompted direct efforts to use measurable characteristics to compare diamonds from different localities. The lead article by Evan Smith and coauthors discusses the recent methods and challenges associated with determining the geographic origin of diamonds and concludes that retaining origin information from the time of mining is the only definitive means of establishing provenance.
SAPPHIRE BENEATH THE RICH BLACK SOIL OF MULING, NORTHEASTERN CHINA
Yimiao Liu and Ren Lu characterize the gemological properties, chemical composition, and provenance-related features of sapphire found in Muling, northeastern China, comparing them against samples from other well-known corundum sources worldwide. Their research provides preliminary data to aid in the origin determination of this underexplored sapphire resource.
GEMS ON CANVAS: PIGMENTS HISTORICALLY SOURCED FROM GEM MATERIALS
Pigments derived from gem materials have been utilized for centuries, from ancient cave drawings to classical and modern works of art. These artistic creations reveal the evolution of the human experience and the progression of anthropological and chemical studies. In this article, Britni LeCroy examines the correlation between the evolution of gem pigment technology and historical art movements.
COLOR MECHANISM AND SPECTROSCOPIC THERMAL VARIATION OF PINK SPINEL REPORTEDLY FROM KUH-I-LAL, TAJIKISTAN
A team led by Yicen Liu uses spectroscopy and chemical analysis to study the color mechanism of pink spinel reportedly from the Kuh-i-Lal deposit in Tajikistan. When heated to a series of temperatures, the spinel samples showed that a combination of spectroscopic thermal variation characteristics causes their pink color.
GIA’s global laboratory staff present their latest findings in the Lab Notes section, including an exceptionally rare 1.21 ct Fancy orangy red diamond, a star sapphire from the legendary Kashmir deposit, and a synthetic moissanite carved to resemble a natural rough diamond.
The Micro-World section, dedicated to the inner world of gemstones, features an unusual bright purple fluid in rock crystal quartz, a partially exposed orange rutile crystal in a color-change diamond, and an eye-catching cluster of zircon needles in a stellate formation in Paraíba tourmaline.
Diamond Reflections returns to examine the fluid droplets trapped within diamond during growth in the earth’s mantle. These liquids reflect the various natural processes that occur during diamond formation and provide scientists with a window into the great depths of our planet.
GEM NEWS INTERNATIONAL
Finally, GNI contributors report on saltwater cultured pearls containing non-traditional “box bead” nuclei fashioned from shell, a type of quartz featuring multiple color zones with oriented inclusions, an update on the current state of Mozambique’s ruby mines, and the first-ever Turquoise United conference.
Brooke Goedert is associate editor of Gems & Gemology at GIA in Carlsbad, California.