Publication Year: - Title: Type Ib Diamond Formation and Preservation in the West African Lithospheric Mantle: Re–Os Age Constraints from Sulphide Inclusions in Zimmi Diamonds Abstract: This article was published in Precambrian Research 286, 152-166.

	Abstract
Ten sulphide inclusions in three diamonds from the Zimmi (West Africa) alluvial diamond locality were analysed for their bulk Fe–Cu–Ni–Co contents and Re–Os isotopic compositions. The host diamonds are exceptionally rare, Ib types that still preserve isolated nitrogen (C centres), rather than more common nitrogen pairs (A centres) and nitrogen aggregates (B centres). C centres in Zimmi diamonds require that they did not experience temperatures above 850 °C for any extended period. Such diamonds make up less than 0.1 % of natural gem diamonds and have never before been dated. The sulphides are pyrrhotite-rich, have low Ni and Os contents, and radiogenic 187Os/188Os, all features characteristic of eclogitic sulphides. Each diamond has 3–4 individual inclusions. 187Re/188Os and 187Os/188Os data fall along three individual ~650 Ma age arrays that represent essentially 3-point or 4-point mineral isochrons for each diamond – unambiguously dating the time of diamond formation. The ~650 Ma age correlates with the timing of Neoproterozoic assembly of Gondwana, recorded in the Rokelide orogen along the SW margin of the West African craton. The initial 187Os/188Os of the three age arrays fall between 1.6 and 2.2 and are highly radiogenic compared to chondritic mantle at 650 Ma. Along with low Re/Os ratios, these data suggests that sulphides were not derived from Neoproterozoic subducting slabs, but rather from older eclogitic material already present in the West African lithospheric mantle. The age of the diamonds and their nitrogen substitutional characteristics, along with their residence in a lithospheric mantle with a normal cratonic geotherm (determined here from Koidu clinopyroxene xenocrysts) suggests that after diamond formation they were rapidly exhumed to shallower depths in the lithosphere. This likely occurred through tectonic uplift following Neoproterozoic continental collision.

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aGemological Institute of America, 50 West 47th Street, New York City, NY 10036, USA

bDepartment of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Road NW, Washington, DC 20015, USA @chapter:29


Publication Year: 1997 Title: Winter 1997 G&G Book Reviews Abstract: “Creative Variations in Jewelry Design”
By Maurice P. Galli, Dominique Rivière, and Fanfan Li, 527 pp., illus., publ. by Schiffer Publishing, Atglen, PA, 1997. US$69.95

“Visual Optics: Diamond and Gem Identification Without Instruments—The Hodgkinson Method”
By Alan Hodgkinson, 50 pp., illus., publ. by Gemworld International, Northbrook, IL, 1995. US$25.00

To view the full section, download the PDF above. @chapter:26


Publication Year: 2023 Title: New Find of Petroleum-Included Quartz from Madagascar Abstract: Figure 1. These two quartz crystal scepters containing a multitude of complex petroleum fluid inclusions (left) that fluoresce yellow to blue to long-wave UV light (right) are from a new deposit in Madagascar. The larger crystal weighs 11.05 ct and measures 22.81 mm in length. Photos by Annie Haynes; courtesy of Hidden Gem Gallery.
At the Tucson Gem and Mineral Show (TGMS), a new find of quartz with petroleum inclusions was offered for sale by Hidden Gem Gallery (Portland, Oregon). According to owner G. Moses Samora, the material is from the Andranotokana Massif in the Alaotra-Mangoro region of eastern Madagascar. Petroleum inclusions in quartz have been seen for a number of years from many deposits, most notably from Baluchistan, Pakistan (Spring 2004 Gem News International, pp. 79–80). The petroleum in these quartz crystals from Madagascar appeared brownish yellow and, as with many other petroleum inclusions in quartz, reacted to long-wave UV light with yellow to blue fluorescence (figure 1).

Figure 2. The new find of quartz from Madagascar contained complex fluid inclusions consisting primarily of petroleum, methane, asphaltite, and water (left). When exposed to long-wave UV light, the petroleum appeared to fluoresce a strong yellow. However, the digital camera used to capture the image registered the fluorescence as a blue color (right). Photomicrographs by Nathan Renfro; field of view 2.81 mm.
Microscopic examination revealed numerous complex fluid inclusions containing obvious brownish yellow petroleum, a gas bubble presumed to be methane, dark solids of what was likely asphaltite, and a colorless immiscible liquid that was probably water (figure 2). Interestingly, in some fluid inclusions the methane bubble was mobile provided there was enough available space within the petroleum-filled cavities. These components are consistent with petroleum fluid inclusions in quartz from other deposits. When exposed to long-wave UV light, the petroleum component strongly fluoresced light yellow (which appeared blue in the photomicrographs), as has been previously observed in similar material. The two crystals from this new deposit displayed a scepter morphology, which seems unusual, though it remains unclear whether this is diagnostic for the locality or just unique to these specific examples.
Microscopic inclusions in quartz are enjoyable to examine, and petroleum inclusions are of particular interest to the collector due to their spectacular UV reaction. The introduction of this new quartz find at the Tucson show is an exciting addition to the gem and mineral trade. @chapter:5


Publication Year: - Title: Romancing the Source: Montana Sapphires Abstract: Montana Sapphires

	Big sky, mountains, rivers, forests, deer, and sapphires. Join the GIA field team on a speedboat ride, visit sapphire mines, see sapphires pulled straight out of the jig, witness the science of heat treatment, and feel the passion of the miners and their customers.

	Montana’s rich history of gold and sapphire goes back to the late 1800s. A GIA field team traveled to the Rock Creek and Missouri River areas, where sapphire mining is still underway, to document the current industry and collect rough sapphire samples for our research reference sample collection. During our time in Montana we visited three mining operations, each with its own business model and its own exciting story. They all shared some common traits, however: amazing natural beauty and a passion for both the area and sapphires.

After a hard day of mining, Mike Cumley pulls a pastel green Montana sapphire right out of the jig—the first time it has been seen by anyone. Photo by Andrew Lucas/GIA, courtesy Spokane Bar Mine.

	Join us on this adventure and learn about the legacy of North American gemstones as we travel by speedboat with a mine owner down the Missouri River, witnessing historical mining sites and current operations. Then visit their mine (Spokane Bar Mine) with us, where we document the entire mining process, and feel the thrill at the end of the day when we pull rough sapphires right out of the jig. The Spokane Bar Mine usually mines for tourists, but on this day we had the entire mine to ourselves to collect samples for the GIA reference collection.

	Come to Gem Mountain and see passionate tourists wash and sort sapphire-bearing gravel to find rough sapphire treasure. Witness the rarely seen world of sapphire heat treatment as Chris Cooney demonstrates the art and science of heating Montana sapphires for the excited customers who have just found them. Join us at a new, well-funded commercial venture looking to start a new golden age of Montana sapphire production, with plans to market the rough to discerning jewelers and recreate the brand name of Rock Creek Montana sapphires.

	Come with us to Big Sky Country, where the land’s natural beauty is matched only by the beautiful sapphires it provides. @chapter:24


Publication Year: 2022 Title: Repaired Grandidierite Abstract: Figure 1. Flattened gas bubbles caught in the break of a filled fracture are visible face up in this 1.43 ct repaired grandidierite. Photo by Annie Haynes.
Recently the Carlsbad laboratory received for identification services a transparent bluish green stone weighing 1.43 ct and measuring 7.47 × 6.31 × 4.06 mm (figure 1). Standard gemological testing revealed a refractive index of 1.58–1.62 on both the crown and pavilion, suggesting that both the crown and pavilion were grandidierite. This was confirmed using FTIR and Raman spectroscopy. Microscopic examination showed a very large fracture that broke continuously around the entire stone. Closer inspection revealed that the fracture was filled (figure 2), and this filling was holding the stone together, indicating that the stone was likely broken into two pieces and then repaired with a resin or glue.

Figure 2. Flattened gas bubbles caught in the filling of the large fracture that breaks continuously through the entire pavilion and some of the crown. Photomicrograph by Michaela Stephan; field of view 4.79 mm.
Grandidierite is a very rare mineral, and transparent gem-quality material was not found in the market until 2015 (Winter 2015 Gem News International, pp. 449–450). Named after French naturalist Alfred Grandidier (1836–1912), grandidierite was first discovered in 1902 at the cliffs of Andrahomana on the southern coast of Madagascar (D. Bruyere et al., “A new deposit of gem-quality grandidierite in Madagascar,” Fall 2016 G&G, pp. 266–275). This is the first repaired grandidierite GIA has seen to date. @chapter:4


Publication Year: - Title: Career Fair Bridges Gap Between Grads, Employers Abstract: Designer Erica Courtney offers advice to a job seeker at GIA Career Fair in Carlsbad. These coaching sessions are a rare opportunity for aspiring professionals to meet with someone who has been successful in the industry.

The following is excerpted from “Legacy of Leadership: A History of the Gemological Institute of America” (2003).

	Back in early 1991, Kathryn Kimmel [then GIA director of Marketing] faced an altogether different type of challenge, one that went beyond branding or advertising and marketing campaigns. Her industry contacts and extensive retail and jewelry manufacturing experience were in demand throughout the Institute in more ways than she had anticipated. Kimmel recalled, “I had a steady stream of students passing through my office who had completed their education at GIA and were ready to move out into the world, but were looking for guidance on how to do it.”

	Kimmel was dedicated to helping these students, but at most she could mentor only a few each year. There were hundreds more, many of them starting second careers, who needed assistance. While GIA maintained a listing of job opportunities, it had no formal program to facilitate networking between students and the trade. Something needed to be done.

	Kimmel knew from her experience in the trade that there was a huge demand for new talent. Now she could see firsthand that the talent was available—the problem was how to bring demand and supply together. She proposed a solution to [then president, Bill] Boyajian: a GIA-hosted “career fair” that would bring GIA students together with industry figures, both to teach the students more about searching for a job and to introduce them to the trade. Boyajian backed the idea, and Kimmel got to work.

	The first place Kimmel went was the 24 Karat Club of Southern California, where she had been a board member for six years. She pitched the idea to her longtime friend Howard Sherwood. Sherwood immediately agreed to be her co-chair, but others were not as convinced. “Some of them told me it was impossible,” Kimmel said. “I responded, ‘Just watch!’”

	Throughout that summer of 1991, Kimmel worked with a steering committee assembled from members of the 24 Karat Club, among them the club’s president, Jack Zemer; Bart Boydston and Earl Lynch of the Diamond Promotion Service; Lynn Diamond of National Jeweler; and Matt Runci of the Manufacturing Jewelers & Silversmiths of America. The committee set out to build support, financial and otherwise, for a GIA Career Fair. One by one, the doubters were won over, and momentum grew rapidly.

	The first Career Fair was held at GIA’s Santa Monica campus in October 1991, in conjunction with the 24 Karat Club of Southern California’s annual dinner dance. Two hundred and fifty students attended a series of panel discussions on job opportunities in the gem and jewelry industry, the various fields within the trade, and how to move from the classroom to a full-time job. In addition, 23 companies came to recruit.

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	Left: Kathryn Kimmel, co-founder of Career Fair, speaks during a panel. Right: A recruiter meets with a job seeker at GIA Career Fair in Carlsbad.

	Industry response was enthusiastic. When the second Career Fair was held in 1992, something new became its most successful feature: one-on-one guidance from industry leaders on how to find openings and prepare resumés, and to hear about trade opportunities firsthand. “We had a lot of smart students who had little experience in preparing a resumé,” Kimmel said.

	In January 1993, GIA New York inaugurated its own Career Fair. Kimmel believed that Career Fair could do far more than recruit GIA students for industry jobs—it could also attract talented people to the industry. It was a promise that was realized more fully than Kimmel anticipated.

	For the Zale Corp., then the largest U.S. jewelry retailer, Career Fair was “our premier recruitment event,” said Susan Goodfellow, the company’s staffing manager, in 1998. “We [come] looking for regional managers, store managers, and sales associates nationwide. We [hire] jewelry professionals at all levels of expertise, including buyers and store operations personnel.”

	By 2002, the Career Fair in New York was attracting more than 1,000 people, while Carlsbad drew more than 800. With the success of GIA’s Career Fair on both coasts, the trade had come to view it as one of the most important services provided by the Institute, not in the least because it was the largest formal recruiting opportunity in the industry. A modest gathering held before the 24 Karat Club’s annual dinner had grown into a major industry event where GIA students and jobseekers from outside the industry were able to rub elbows with executives from major jewelry companies.

	“Career Fair has done more than just find jobs and mentors for thousands of students,” Kimmel said. “It attracted a lot of new talent to the industry, and it allowed industry figures to give back. When people come up to me and say, ‘I went to Career Fair eight years ago, and I didn’t know a thing, and now I’m vice president of a major jewelry company,’ that’s when I know it really paid off. It’s truly the last bridge from GIA to the trade, and from the trade to our students.”

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	A Carlsbad Career Fair attendee meets with designer Paul Klecka for an informal coaching session. @chapter:36


Publication Year: 2015 Title: Iridescent Musgravite Abstract: Figure 1. This 0.86 ct gray musgravite displays an unusual iridescent phenomenon that is clearly visible in the table facet. Photo by Kevin Schumacher.

Musgravite is a rare mineral closely related by composition to the mineral taaffeite. This magnesium-rich beryllium oxide crystallizes in the trigonal system, in contrast to the hexagonal system of taaffeite, and is highly sought after by rare stone collectors. A 0.86 ct musgravite, identified by Raman spectroscopy, contained a particularly interesting inclusion scene consisting of numerous etch tubes that broke the surface of the faceted stone (figure 1). With a direct source of light, these etch tubes displayed vibrant colors resulting from thin-film iridescence in the air-filled, crystallographically aligned tubes (figure 2). This is the first musgravite gemstone displaying any type of optical phenomenon that this author has examined to date.

Figure 2. Thin-film iridescence along crystallographically oriented etch tubes was the source of the colorful phenomenon in this rare musgravite gemstone, viewed using oblique fiber-optic illumination. Field of view 2.47 mm. Photomicrograph by Nathan Renfro. @chapter:10


Publication Year: 2018 Title: Suggested Reading on Diamond Inclusions Abstract: Breeding C.M., Eaton-Magaña S., Shigley J.E. (2018) Natural-color green diamonds: A beautiful conundrum. G&G, Vol. 54, No. 1, pp. 2–27, http://dx.doi.org/10.5741/GEMS.54.1.2
Eaton-Magaña S., Breeding C.M. (2018) Features of synthetic diamonds. G&G, Vol. 54, No. 2, pp. 202–204, http://dx.doi.org/10.5741/GEMS.54.2.202
Eaton-Magaña S., Breeding C.M., Shigley J.E. (2018) Natural-color blue, gray and violet diamonds: Allure of the deep. G&G, Vol. 54, No. 2, pp. 112–131, http://dx.doi.org/10.5741/GEMS.54.2.112
Eaton-Magaña S., Shigley J.E., Breeding C.M. (2017) Observations on HPHT-grown synthetic diamonds: A review. G&G, Vol. 53, No. 3, pp. 262–284, http://dx.doi.org/10.5741/GEMS.53.3.262
Koivula J.I. (2000) The MicroWorld of Diamonds. Gemworld International, Northbrook, IL, Inc., 157 pp.
Shirey S.B., Shigley J.E. (2013) Recent advances in the understanding the geology of diamonds. G&G, Vol. 49, No. 4, pp. 199–222, http://dx.doi.org/10.5741/GEMS.49.4.199
Smit K.V., Myagkaya E., Persaud S., Wang W. (2018) Black diamonds from Marange (Zimbabwe): A result of natural irradiation and graphite inclusions. G&G, Vol. 54, No. 2, pp. 132–148, http://dx.doi.org/10.5741/GEMS.54.2.132
Smith E.M., Shirey S.B., Nestola F., Bullock E.S., Wang J.H., Richardson S.H., Wang W. (2016) Large gem diamonds from metallic liquid in Earth’s deep mantle. Science, Vol. 354, No. 6318, pp. 1403–1405.
Smith E.M., Shirey S.B., Richardson S.H., Nestola F., Bullock E.S., Wang J.H., Wang W. (2018) Blue boron-bearing diamonds from the Earth’s lower mantle. Nature, Vol. 560, No. 7716, pp. 84–87.
Smith E.M., Shirey S.B., Wang W. (2017) The very deep origin of the world’s biggest diamonds. G&G, Vol. 53, No. 4, pp. 388–403, http://dx.doi.org/10.5741/GEMS.53.4.388 @chapter:35


Publication Year: 2016 Title: “Star of David” Spinel Twin Crystal with Multiphase Inclusions from Mogok Abstract: Figure 1. This 12-sided crystal recently obtained in Mogok is a rare spinel macle, hosting fascinating multiphase (liquid + gas) inclusions. The stone is reportedly from the eastern part of the Mogok Valley. Photo by Victoria Raynaud/GIA; field of view 5.7 mm.

	In December 2015, author VP obtained from the Mogok gem market a remarkable spinel crystal with a fascinating Star of David (figure 1). This unusual pattern was formed by two triangles on opposing sides of a central 12-sided polygon. Furthermore, the specimen hosted some conspicuous crystals that resembled fluid inclusions, which are rare in spinel. The stone was reportedly mined in the early 2000s near Pein Pyit, a village in eastern Mogok that is famous for such twinned spinel crystals (T. Themelis, Gems & Mines of Mogok, published by the author, Bangkok, 2008). Hundreds were found in the Mogok market between 2002 and 2004, but most were tiny or broken (V. Pardieu, “Hunting for ‘Jedi’ spinels in Mogok,” Spring 2014 G&G, pp. 46–57). The newly acquired crystal was added to the GIA reference collection. With a chemical formula of MgAl2O4, spinel belongs to the cubic crystal system. It is often found as octahedrons (with o faces), but sometimes dodecahedron d faces are visible. This specimen presents a fascinating case of twinning parallel to the octahedral plane O (111), commonly called “spinel-law” twinning. The general crystal outline is a 12-sided polygon instead of the expected hexagon. If a spinel crystal shows only o faces, a crystal flattened along the (111) plane will appear as a hexagon. But a spinel with both o and d faces that is flattened along the (111) octahedral plane will show 12 sides, as in this specimen.

	The crystal hosted several fractures as well as interesting fluid and crystal inclusions. Fractures are very common in such thin crystals, causing them to break easily. This specimen broke during the cleaning process (figure 2), and extra care should be taken while handling such crystals.

Figure 2. The Star of David spinel hosts some interesting multiphase inclusions. Such fractured, thin crystals are very brittle; this one was damaged during the cleaning process. Photo by Sasithorn Engniwat/GIA.

	One inclusion was a flat, opaque, and foliated black crystal (possibly graphite) that we could not identify with Raman spectroscopy. There were also carbonate inclusions (identified as calcite and dolomite using Raman spectroscopy). The most fascinating features were the multiphase inclusions; at least eight were located in the center of the specimen (figure 3). They were composed of a negative crystal filled with colorless liquid, hosting a flattened or spherical bubble, filled with a liquid and a gas. This was unlike the features in spinel from Man Sin, where negative crystals are filled with an orange liquid rich in sulfur (again, see Pardieu, 2014).

Figure 3. About five multiphase inclusions associated with colorless carbonate crystal are seen in the spinel’s center, shown using diffused brightfield illumination. Photo by Victoria Raynaud/GIA; field of view 2.40 mm.

	We assumed that the gas inclusions were mainly CO2, as some of the small bubbles disappeared while the stone was under the microscope and gently heated by the well light. This could not be confirmed by Raman analysis; the CO2 concentration in the solution may have been too low.

	FTIR spectroscopy confirmed the presence of carbonates and oil in some fractures. This might be explained by the common practice (in Mogok) of keeping crystals in oil before selling them. We also studied the sample using photoluminescence and UV-Vis spectroscopy. The Cr3+ band in the PL spectra was approximately 0.89 nm wide. In the UV-Vis spectra, there was a clear absorption in the green around 537 nm. These features confirmed the absence of treatment (S. Saeseaw et al., “Distinguishing heated from unheated spinel,” GIA News from Research, 2009).

	The sample was analyzed using LA-ICP-MS. Three spots were studied and compared to GIA reference data obtained on other red spinels from different origins. The main trace elements observed were V, Cr, and Zn. Other elements (Li, Be, Ti, Mn, Fe, Co, Ni, and Ga) were also detected in lower but still significant concentrations. Based on GIA’s reference data for origin determination, we would have identified these as Burmese, with other localities (Tanzania, Vietnam, or Tajikistan) excluded due to the elevated Zn and Ni content.

	Star of David spinels are rare crystals that fascinate many gemologists and collectors. Studying these macles promotes our understanding of them and will contribute to origin determination for red spinel. @chapter:10


Publication Year: 2023 Title: Delve into the jewelry and accessories market in China. Abstract: Consumers in tier 1 and tier 3/4 cities exhibit notable differences in their preferences. The ratio of purchasing gold and diamonds remains highest in tier 1 cities. Meanwhile, consumers in tier 3/4 cities also show significant demand for both gold and diamonds, though slightly less than tier 1. Over the past 2-3 years, tier 1 consumers have shown an increasing preference for high-end products, opting for diamonds and platinum more frequently. In contrast, tier 3/4 consumers continue to favor gold.

Furthermore, when segmented by jewelry type, Chinese consumers show varying preferences:
Gold: Due to economic development and innovation in pearl and jewelry production, designs and craftsmanship of gold have become more modern and attractive. Chinese consumers favor pure gold, such as 24K, pure gold 9, and 99.99, which are highly popular. In 2565, total gold consumption reached 1,001.74 tons.
Diamonds: Majority of Chinese consumers purchase diamonds for significant occasions like weddings or as gifts.
Jade: Jade holds greater cultural and symbolic value than gold. Chinese consumers often collect jade as heirlooms that can be passed down through generations.
Colored Gemstones: Popular colored gemstones include sapphires, emeralds, rubies, amethysts, and topaz. These are commonly used in earrings, necklaces, and rings, often combined with other materials like silver and diamonds.
Silver: Silver jewelry is more affordable and popular among Chinese consumers, often combined with colored gemstones to enhance aesthetic appeal.
Manufacturing of pearls and jewelry in China is concentrated in major regions like Guangdong, Beijing, Shanghai, and Hong Kong. Notably, Shenzhen, Guangzhou, and Dongguan are prominent for their renowned jewelry businesses, with Shenzhen alone hosting 21 reputable companies.
White Gold Jewelry: Africa is the largest producer of white gold globally, with China relying significantly on imports. Despite being less valuable than gold, white gold jewelry is preferred for its aesthetic appeal.
Diamond Production: China is a major global producer of diamonds, cultivating a significant portion domestically. In 2565, diamond production in China totaled 82,000 million carats. Chinese consumers are also major importers of rough diamonds, sourcing from various countries such as South Africa, Russia, Japan, Germany, and Belgium.
Jade Varieties: Different types of jade originate from various regions, including Hetian jade from Xinjiang (white, lavender, and Jasper green), Lanshan jade from Sichuan (white and green with traces of blue), Tushan jade from Shanxi (purple, black, blue, green, red, and mixed colors), and Xiuyan jade from Liaoning (sea-green and dark green).
Market Value: The jewelry market in China was valued at 720 billion yuan in 2564, marking an 18% increase from 2563. By 2565, it further increased to 800 billion yuan, an 11.11% rise from the previous year. Local brands like Lao Feng Xiang, Chow Sang Sang, and Chow Tai Fook are renowned for gold jewelry, while luxury brands like BVLGARI and Tiffany dominate the high-end market."
This translation provides a comprehensive overview of the jewelry consumption patterns and market dynamics in China across different tiers of cities and various types of jewelry. @chapter:27


Publication Year: 2018 Title: Cabochons Fashioned from the Shell of Crassostrea Virginica Abstract: Figure 1. The ten cabochon-cut gems examined are shown alongside the valves of C. virginica (Eastern or American oyster). The interior and exterior valves shown belong to one oyster. Photo by Diego Sanchez; samples courtesy of Anne Dale.

Crassostrea virginica, the so-called Eastern or American oyster, is a commercial seafood widely distributed along the east coast of the United States to the Gulf of Mexico (“Indian River Lagoon Species Inventory,” Smithsonian Marine Station at Fort Pierce, 2008, https://www.sms.si.edu/irlspec/Crassostrea_virginica.htm). Connecticut, Virginia, and Mississippi have all designated the Eastern oyster as their official state shell, and cabochons cut from this bivalve are the official state gemstone of Louisiana (http://legis.la.gov/Legis/Law.aspx?d=103557). These specimens are marketed under the trade name LaPearlite.

Figure 2. Left: A 3.09 ct cabochon showed various surface structures consisting of a non-directional patchwork of cells near the center to a broad mottled appearance in the outer area, together with natural brownish layers of shell formation. Right: Higher magnification of another cabochon’s surface revealed a distinct patchwork structure. Both samples displayed a whitish sheen on the surface when illuminated with a fiber-optic light. Photomicrographs by Artitaya Homkrajae; fields of view 11.90 mm (left) and 5.24 mm (right).
The Carlsbad laboratory received ten LaPearlite cabochons together with a shell for examination (figure 1). The cabochons exhibited low domes and flat bases and ranged from 1.65 to 6.12 ct. They measured from 6.85 × 6.60 × 3.80 mm to 14.40 × 10.30 × 5.30 mm and possessed non-nacreous surfaces, with the majority displaying a natural brownish yellow banded structure typical of shell formation. Microscopic examination revealed that the main white surface and subsurface structure varied from a patchwork of nondirectional cells or segments to a broad mottled appearance within individual specimens, as well as from specimen to specimen. These structures exhibited a reflective whitish sheen when illuminated by a fiber-optic light or other bright oblique lighting, creating a shimmery phenomenon (figure 2). A similar patchwork pattern has been noted on scallop pearls and shells of the Pectinidae family (K. Scarratt and H.A. Hänni, “Pearl from the lion’s paw scallop,” Journal of Gemmology, Vol. 29, No. 4, 2004, pp. 193–203). Under long-wave UV radiation (365 nm), the white portions of all the cabochons and the shell were inert, while the yellow portions showed a weak to moderate yellow fluorescence, and the shell’s dark purple adductor muscle scar exhibited a weak red fluorescence.

Figure 3. Raman spectra collected using 514 nm laser excitation on the white and purple areas of the interior of the C. virginica valve. The white area shows calcite peaks at 280, 712, 1085, and 1437 cm–1, and the purple area shows aragonite peaks at 703 and 1085 cm–1, along with several broad pigment-related bands.

Figure 4. A PL spectrum collected using 514 nm laser excitation on a purple area on the interior of a C. virginica valve displays clear triple bands at approximately 620, 650, and 680 nm related to the porphyrin pigment.
Raman spectroscopic analysis with a 514 nm argon-ion laser subsequently verified that the white and yellow portions of the cabochons and shell were calcite with peaks at 280, 712, 1085, and 1437 cm–1. No peaks indicating the possible presence of pigments were detected in the yellow areas. Moreover, Raman spectra collected on the shell’s dark purple adductor muscle scar produced aragonite peaks at 703 and 1085 cm–1 along with several relatively weak broad pigment-related bands (figure 3). PL spectra collected with 514 nm laser excitation on the same areas showed clear triple bands at approximately 620, 650, and 680 nm (figure 4). The PL spectra and fluorescence reaction indicate the purple color is associated with the pigment porphyrin (Y. Iwahashi and S. Akamatsu, “Porphyrin pigment in black-lip pearls and its application to pearl identification,” Fisheries Science, Vol. 60, No. 1, 1994, pp. 69–71; L.H. Arma et al., “Red fluorescence lamellas in calcite prismatic layer of Pinctada vulgaris shell (Mollus, bivalvia),” Optical Materials Express, Vol. 4, No. 9, 2014, pp. 1813–1823). None of the studied cabochons showed purple areas to examine for comparison. Interestingly, the Raman spectra obtained from the white and purple areas of the same mollusk that were previously referenced in the literature (K. Scarratt et al., “A note on a pearl attached to the interior of Crassostrea virginica (Gmelin, 1791) (an edible oyster, common names, American or Eastern oyster),” Vol. 30, No. 1/2, 2006, pp. 43–50) differed slightly from the findings in Journal of Gemmology this work. The samples in this submission were also analyzed by energy-dispersive X-ray fluorescence (EDXRF) chemical analysis and showed low levels of manganese (Mn), confirming their saltwater environment.
As with all shell mollusks, C. virginica is capable of producing pearls. However, the cabochons in this study provided useful gemological and spectroscopic information for future reference that can no doubt assist with identifying the composition of pearls produced by the mollusk (C.P. Idyll, “The pearls of Margarita,” Americas, Vol. 19, No. 8, 1967, pp. 8–14). Although the samples could be mistaken for agate at first glance, owing to their distinctive banding, it would soon be apparent that they were pieces of fashioned shell. The samples demonstrate how creative work can turn nature’s beauty into an attractive gemological material. @chapter:14


Publication Year: - Title: Jade Report: Increased Mining Creates Large Stockpiles Abstract: The Hutton-Mdivani Jade Necklace, containing 27 translucent green jadeite beads sold for $27.4 million – more than $1 million per bead – at Sotheby’s Magnificent Jewels and Jadeite Sale on April 7, 2014 in Hong Kong. The beads graduate in size from 15.4 mm to 19.2 mm.   Photo courtesy of Sotheby’s

	The Chinese retail market has been cooling off, but jade mining in the Kachin province of Myanmar has been on the increase, causing a massive inventory buildup, according to a report by the Ash Center for Democratic Governance and Innovation of Harvard University.

	The report is based on information from government sources and traders in Hpakant, Kachin province, the 30-square-mile source for nearly all jadeite. The authors noted that production began to expand in 2015 and jade dealers in Hong Kong corroborated the report’s observation of large and growing stockpiles of the gem in warehouses near the Myanmar border and dealers’ safes. It does not estimate the size of jade stocks, but interviews with others involved in or monitoring the jade trade agree it is extremely large.

	“If China wanted to whittle down their stockpiles, they probably could do without (newly produced) jade for five to 10 years,” said one Myanmar-based official with close connections to dealers and the government.

	Jade stocks are accumulating because production has far exceeded the market’s ability to absorb it. Some goods are locked in customs over ongoing valuation disputes and, more recently, there is a reluctance to sell better quality materials because prices have been softening. Producers and dealers can sit on large stocks because capital costs of mining are low and they do not rely on bank financing and don’t accumulate additional costs by holding inventory.

	The report shows that jade production for the first nine months of 2015 (the latest available figures) totaled 24,000 metric tons, or 2.5 times the same period in 2014.

	Myanmar’s central government cannot control illegal mining, according to the report, because it is involved with the rebel Kachin Independence Army, which has ratcheted up campaigns against it. The government has tried to limit access to the Hpakant region, by restricting new mining licenses and attempting to suspend mining after a series of deadly rock falls.

	But mining for jade continues and as many as 200,000 unlicensed diggers continue to work the extensive waste piles, which has created enormous social problems and unsafe conditions. Nine diggers were killed on Feb. 10 when a slag pile collapsed onto them, according to a report in Radio Free Asia.

Dealers and buyers at a 2012 jade market at Amarapura, now a suburb of Mandalay, in Myanmar. Photo courtesy of Maxine Hesse

	Retail Demand for Jade is Decreasing

	The Ash Center estimated jade production at Hpakant to be worth $7.9 billion in 2011, possibly increasing to $15 billion in 2015 because of the rise in mining activity. A 2015 Global Witness report estimated the jade trade at $31 billion, a figure most analysts agree is excessive. To put that number in perspective, worldwide rough diamond production in 2015 was valued at just under $14 billion, with the worldwide polished wholesale market valued at $22 billion.

	Chinese jewelry retailers report that jade sales slowed by 20% or more in 2016. Jade dealers at the September 2016 Hong Kong Watch and Jewellery Show noted that prices for the gem, even top quality “A” material, had fallen substantially − 20% to 40% in the past two years − as the Chinese government began to crack down on large cash purchases as a way to curtail corruption. In addition, the Chinese government also enacted an excise tax on jade imports to discourage demand.

	China’s top retailers do not break down sales by gemstone categories, but the country’s largest chain, Hong Kong-based Chow Tai Fook’s 2,057 stores logged sales of $7.2 billion in 2016, down from a 2014 peak of $9.9 billion. Gem-set pieces (including jade) account for 27% of the company’s sales.

	Sales at Chow Sang Sang, another prominent Chinese jewelry retail chain, fell 16% in fiscal 2016, to just over $1 billion and Luk Fook Holding’s, also a large jewelry chain, saw its sales decline 21% in fiscal 2016 to $700 million.

	The majority of jade is worked on in China with an estimated 500,000 people employed in various stages of processing, according to dealers. It is mostly sold through specialized retailers or traditional marketplaces that don’t disclose their sales activity. An increasing amount of medium quality “B” and lower quality “C” jade, however, is being sold via Chinese internet sites such as Weibo and WeChat. These internet sales are hurting traditional jade retailers, according to reports in China.

Pieces of mined boulders show ribbons of jade running through them. This one was found in Mandalay, Myanmar. Photo by Robert C. Kammerling/GIA

	The Future of Myanmar Jade Mining

	Regaining sufficient control over Myanmar’s jade production to regulate production, enforce environmental and safety standards, and restore government revenues would be a very difficult task, according to the Ash Center report.

	The conflict in Kachin, a large province in the north central portion of the country, has been raging for years. Some officials of the Kachin Independence Army earn money trafficking in illicitly mined jade, in addition to “tolls” collected from individuals and companies traveling through the area, according to the report. Any settlement must take these factors into account.

	Complicating matters, mine concession owners, many of whom are Chinese, need to be willing to pay sufficient taxes to support government health and education programs, particularly because drug addiction remains rampant, especially among miners, who require these social services.

	The Ash Center has proposed a revenue sharing structure that will enable mine owners to keep their concessions, while paying royalties of 50% on the full wholesale value of jade exported, plus business taxes. An elected government in Kachin, supported by both the military and separatists groups, would enforce environmental policies and provide health and education services to the populace. Non-Governmental Organizations could serve as monitors to ensure those standards are upheld.

	The report also maintains that an equitable power-sharing arrangement would make it possible to develop hydroelectric power operations and the ability to responsibly mine other resources in the area, including amber and gold. @chapter:33


Publication Year: 1998 Title: Summer 1998 Gem News International Abstract: Diamonds
            Diamond Exploration in Alberta, Canada
            Anticipated Production in the Northwest Territories
            International Rough Diamond Conference in Israel
Colored Stones and Organic Materials
            “Flame Agate”: What’s in a Name?
            Update on Benitoite Mining
            Beryl from Madagascar: Aquamarine
            Trapiche Beryl
            “Almost Blue” Sri Lankan Color-Change Garnets
            Cat’s-Eye Opal from Tanzania
            Of Rubies and Rubles
            Star Sapphire from Madagascar
Treatments
            Jadeite Boulder Fakes
            Titanium- and Gold-Coated Drusy Materials in Jewelry
            Surface-Treated Topaz
Instrumentation
            New Faceting Machine
Announcements
            AGTA Announces Tanzanian Miners’ Relief Effort
            Birthstone Exhibit at the Carnegie Museum.
            Ninth Annual Conference of the Canadian Gemmological Association

To view the full section, download the PDF above. @chapter:7


Publication Year: - Title: Jewelry that Speaks the Language of Flowers Abstract: A flower is one of nature’s most delicate and beautiful creations. It’s fitting that jewelry designers have been spellbound by its charm. Orchid: Courtesy of Paula Crevoshay; Lily: Photo by David Behl. © Janet Mavec and GIA; Violet: Courtesy of Cartier. © GIA & Tino Hammid

	A flower is one of nature’s most delicate delights, so it’s natural that jewelry designers have long found inspiration in them, seeking to capture their fleeting beauty in jewelry.

	Flowers are also rich in symbolism. Shakespeare, Jane Austen, and Charlotte Brönte used floral symbolism in their works. Madame Charlotte de la Tour formalized their meanings in her 1852 book, The Language of Flowers.

	Jewelry and floriography often cross paths. We share with you some breathtaking examples.

Wisteria

Courtesy of Ineke Peskin. © GIA & Tino Hammid

	A fragrant flower that comes in blue, lavender, purple, pink, and white, wisteria symbolizes in Shin Buddhism modesty and contemplation. Because it is a twinning vine, it represented devotion and attachment in Victorian England.

	An antique brooch (circa 1850) is an artful arrangement: it is made of a golden sprig of wisteria and enameled leaves and petals of turquoise. The cluster of flowers and the center stem are set with old mine cut diamonds and a pearl pendant.

Violet

Courtesy of Cartier. © GIA & Tino Hammid

	Named for its rich, vibrant purple hue, violets mean modesty; white violets mean innocence. In The Language of Flowers: A History, Beverly Seaton writes that violets symbolized the Virgin Mary. Curiously, Napoleon used it as his emblem and Narcissus (who fell in love with his own reflection) turned into one.

	This bouquet of violets has amethyst flowers with diamond stamens set in platinum, so both meanings of the flower are expressed. The brooch features gold leaves set with demantoid garnets and channel-set baguette diamond stems.

Bouquet

Courtesy of Neil Lane, Inc., Beverly Hills, California. © GIA & Tino Hammid

	During the Victorian Era (1837-1901), British and Americans gave friends “talking bouquets” or tussie mussies (nosegays and small bouquets of herbs and flowers). Various arrangements had different meanings.

	Carved rubies, sapphires and emerald “flowers” and diamond leaves make for a colorful bouquet. The piece evokes flower baskets given during the holidays.

Orchid

Courtesy of Paula Crevoshay

	Cypripedioideae, or lady slipper orchids represent “capricious behavior.” Cattleya orchids symbolize “mature charms.” Cymbidium orchids represent virtue and integrity. Dendrobium orchids speak of refinement and beauty. Victorians thought the orchid to be an exotic beauty, and wore ones in their hair and placed them in vases.

	Paula Crevoshay’s “Midnight Seduction” lady slipper orchid brooch is vibrant with 195 purple sapphires, 148 blue zircons, blue sapphires, black diamonds, coral, and an abalone pearl.

Lily

Photo by David Behl. © Janet Mavec and GIA

	White lilies represent chastity and virtue, and have been associated with the Virgin Mary. They are also said to symbolize perfection, majesty, and the ideal woman. “Black” lilies (they’re really dark blue and maroon) are given to one’s first love. Yellow lilies represent gaiety. The color red in red lilies denotes desire or passion. King Charles IX of France gave lilies to women of the court on May Day – a tradition that still continues.

	This red lily brooch is exotic and elegant.

Pansy

Courtesy of Lydia Courteille

	Say “think of me” with a blossoming garland of pansies. The name pansy comes from the French penser, meaning to “to think.” Give pansies as a gesture of friendship and platonic love.

	These purple, pink, and white earrings feature a petal design inspired by pansies. Their open blooms herald nature’s reawakening in the spring. @chapter:16


Publication Year: 1992 Title: Summer 1992 Gem News International Abstract: Diamonds
            Claim-Staking Rush in Canada
            International Diamond Technical Symposium in Israel
            Prospecting Reveals Kimberlite Pipes in Ukraine
            Small Industrials in Uzbekistan
            DeBeers and the Republic of Sakha Sign Sales Agreement
            Visit to a Small Diamond-Mining Operation in South Africa
            DeBeers Signs Prospecting Agreement with Tanzania
            Zaire Produced Fewer Diamonds
            Zaire Tightens Trade Regulations
Colored Stones
            Exotic "Jewel" Beetles
            Cat's-Eye Golden Beryl
            Garnets from Egypt
            Large Jadeite Boulder
            Gemstones from Laos
            Attractive Meteorite Jewelry
            Black Mabe "Pearls" and Simulants (from Nautilus Shell)
            Rare Gemstones from Quebec
            Tajikistan to Develop Gem Resources
Enhancements
            Acrylic Coating of Gem Materials
            Dyed Massive Beryl and Quartz Resembling Ornamental Gems
            Beryl Beads with Multiple Color Enhancements
            Treatable "Concrete" Opal
            Silver-Nitrate-Treated Matrix Opal
            Modern-Day Turquoise Oiling
Synthetics and Simulants
            Assembled Imitation Emerald Crystal
            Update on Nontransparent CZ
            Bicolored CZ
            Blue Spinel from Vietnam as Sapphire Imitator
            Glass Imitation Tourmaline Crystal
            More Synthetics Sold as Natural Rubies from Vietnam
            Experimental Synthetic Sodalite from China
Instrumentation
            Low-Cost Quartz Wedge Simulator

To view the full section, download the PDF above. @chapter:7


Publication Year: 2022 Title: Myne London: Sourcing Emeralds with a Mission Abstract: Figure 1. Emerald rough from Swat Valley, Pakistan. Photo courtesy of Myne London.
In 2018, sisters Fiona Wellington and Kate Murray Gordos founded Myne London (www.mynelondon.co.uk), a London-based ethical emerald supplier with a goal of supporting women in the gem trade. Their emeralds are sourced from lesser-known mines in Swat Valley, Pakistan, where they aim to create a sustainable and responsible emerald industry and a lasting positive economic impact in the community. Inspired by their childhood memories of Pakistan, Wellington and Gordos are dedicated to making Swat Valley’s emeralds globally recognized for their traceability and intense vivid green color (figure 1), all while empowering women.

Figure 2. Eighty percent of the Pakistani lapidaries working in the Myne London workshop are women. Photo courtesy of Myne London.
Myne London partners with local groups in the Swat Valley region, including miners and mine owners. In addition to sourcing the emeralds directly from the miners, Myne London is committed to keeping the lapidary work in Islamabad and providing opportunities for women. Partnering with a local company, they train and hire Pakistani women to cut and polish the emeralds (figure 2), a profession traditionally dominated in the region by men. Myne London, which employs a 75% female workforce, collaborates with jewelry designers worldwide—mainly women—to create exquisite pieces featuring the high-quality emerald melee, in addition to designing its own fine jewelry collections.
But Wellington and Gordos aspire to do even more for their female lapidaries. In 2021, they started the Myne London Foundation, a charitable organization designed to give their employees better access to education, which is limited for girls in the country. Illiteracy rates are higher than 50% for adult women in Pakistan. The money raised by the foundation assists the daughters of female employees with tuition costs, school uniforms, and transportation. Without money to pay for these costs, children in the northern regions of Pakistan often do not attend school. The foundation receives 10% of Myne London’s profits.
In March 2022, Myne London hosted an inaugural charity ball for the foundation, raising nearly $20,000, which has already been put to good use in Pakistan. “We immediately actioned to pay for the daughter of one of our lapidary workers to attend school from now on in Islamabad. She is six years old. We plan to provide this for her for as long as she wishes to stay in education,” said Wellington. “We also are committed to find ways to support girls in sport, because that is a great leveler and improves confidence as well as health.”

Figure 3. Ring designed by Octavia Elizabeth in 18K gold featuring 1.24 carats of Swat Valley emerald. Photo courtesy of Octavia Elizabeth/Myne London.
Outside of Pakistan, Myne London continues its ethos of women’s economic empowerment by collaborating with women around the world in jewelry design. Last year, the company partnered with Los Angeles–based jewelry designer Octavia Zamagias of Octavia Elizabeth, who shares the same social goals. Using 18K gold, Zamagias created several stunning pieces featuring Swat Valley emeralds (figure 3). Looking ahead, Myne London is planning jewelry collaborations with three other talented women—two based in London and the other in Florence.
The firm recently partnered with Opsydia, a gemstone security specialist, to permanently place its brand logo beneath the surface of the Swat Valley emerald melee. Encouraged by Opsydia’s success placing identifiers in melee diamonds, Myne London aims to promote traceability using this innovative technology.
With all their success in Swat Valley, Myne London hopes to expand to other areas of the world someday, using the same model for ethics, traceability, and women’s empowerment. But for now, they remain focused on the women and emeralds of Swat Valley. @chapter:33


Publication Year: 1996 Title: Spring 1996 Gem News International Abstract: TUCSON ‘96
Diamonds
            Matrix Diamond Specimens from China and Russia
            Synthetic Diamonds Are in the Marketplace
            Synthetic Moissanite as a Diamond Simulant
Colored Stones
            Color-Change Garnet
            Heliodor from Tajikistan
            "Leopard Opal" from Mexico
            Cultured Abalone Pearls
            Update on Namibian Spessartine
            Large Taaffeite Crystal from Sri Lanka
            Tanzanite Beads
            Gem Materials from the New Locality at Tunduru, Tanzania
Enhancements
            Update on Polymer-Impregnated Malachite
Synthetics and Simulants
            Beryl Triplets Imitating Paraiba Tourmaline
            Faceted Quartz Construct
MORE FROM THE 25TH INTERNATIONAL GEMMOLOGICAL CONFERENCE
Diamonds
            Fingerprints of Natural Diamonds: Observations with Cathodoluminescence
Colored Stones and Organic Materials
            Mineral Inclusions in Quartz
            Montana Sapphires
            Sapphires and Rubies from Laos
Enhancements
            Durability of Polymer-Impregnated (B-Type) and Natural Jadeite
Instrumentation
            Infrared Spectroscopy of Thai Rubies and Sapphires
            Infrared Spectroscopy Distinguishes Synthetic from Natural Emerald and Quartz
Miscellaneous
            Gems from Archeological Excavations in Rome (Crypta Balbi)
            Gems in a Visigoth Treasure
Announcements
            Treasures of Mexico Exhibit at the Houston Museum

To view the full section, download the PDF above. @chapter:2


Publication Year: 2013 Title: Enriching a Tradition Abstract: Duncan Pay brings more than a decade of gemology education, manufacturing and retail experience to Gems & Gemology as the quarterly’s new editor-in-chief. Photo by Kevin Schumacher.

              As the new editor-in-chief of Gems & Gemology, I thank Jan Iverson for her recent stewardship of the journal. Jan will be taking over as GIA’s director of Education Content Development. I wish her every success in this new role. Let me also thank GIA president and CEO Donna Baker and vice president of Education Bev Hori for giving me this opportunity.

Allow me to introduce myself. My background is in the colored stone industry. I also have extensive experience in jewelry manufacture and retail. Besides being a Graduate Gemologist, I am a Fellow of the Gemological Association of Great Britain (Gem-A). At GIA, I’ve been director of Course Development for over a decade. One of my proudest accomplishments was the recent transformation of our distance-education gemology courses from print to eLearning.

I join G&G at a tremendously exciting time. GIA has the largest cadre of talented research scientists and the most extensive network of labs and research centers in its history. The topics of their investigations have never been wider—or more challenging. And G&G is your window into this exciting world of research.

G&G will be at the center of the Research & News section of the new GIA website, which launches April 30, so please keep this date in mind. The new website provides an unparalleled online knowledge base that will serve your professional needs better than we’ve ever done before.

We’re placing a remarkable resource—almost 80 years—of groundbreaking gemological knowledge at your fingertips. As a visitor to www.gia.edu, you’ll have unrestricted access to every G&G issue back to the journal’s inception in January 1934—full articles, Gem News International, Lab Notes, and all the regular features. And we pledge to continue to provide the highest levels of gemological research in the exacting tradition of G&G’s rich legacy.

G&G has never been more necessary. Let no one to be in any doubt over GIA’s commitment to our journal. We see it as a vital part of a wider system, one that links GIA’s education with its ongoing research, and delivers that essential knowledge to our readers. @chapter:24


Publication Year: 2019 Title: Thoughts on the Chinese and Japanese Gem Markets Abstract: Figure 1. Paraíba tourmaline, such as this 3.71 ct pear-shaped stone, was popular in Japan when Shahin entered the gem trade. Photo courtesy of SR Trading.
At the Tucson shows, Shahin Aboosalih, director of SR Trading, spoke to us about his path to the gemstone and jewelry industry and his company’s gemstone business in Japan and China.
Shahin, as he prefers to be called, comes from four generations of Sri Lankan gem merchants, but initially he took another career path. He spent seven years in the Sri Lankan banking industry and then decided to go to school in Japan to study the language, with no intention of entering the gem industry. In fact, his father always encouraged him to pursue a career outside the gem business. In 1993, after completing his Japanese language studies and gaining experience in computer graphics, Shahin returned to Sri Lanka and joined Dilmah, a major tea exporting company, as a packaging designer. In 1996, he was offered an opportunity to work in Kofu, Japan, by STS Gems Japan Ltd., an Indian multinational colored gemstone and jewelry company. This was his stepping stone to the world of gems. “At that time, I didn’t know what a tanzanite or sapphire was, even though my family had huge knowledge in corundum from Sri Lanka for several generations,” he explained.
When Shahin started in the industry during the 1990s, Japan’s economy was in recession, yet fine gemstones like Paraíba tourmaline (figure 1) were still in demand. As the recession continued, gemstones that were once rare and more difficult to source—such as fine blue star sapphires, emeralds, and Paraíba tourmaline—kept momentum and held their prices.
Sunil Agrawal, CEO of STS and one of Shahin’s early mentors in Japan, taught him everything “from scratch.” The company sent Shahin to Jaipur, India, for several months to learn colored stone identification. Then he traveled to Brazil, India, South Africa, Thailand, and Sri Lanka to find new material to meet the heavy demand from his Japanese clients for a wide range of stones, including fine corundum, spinel, tourmaline of all kinds, and aquamarine. He also learned finer cutting techniques in Sri Lanka from his father-in-law, Naji Sammoon (founder and chairman of Sapphire Cutters (Pvt) Ltd. in Colombo). He used these skills, along with his computer graphics background, to perfect gem cuts and meet the high standards for faceted stones in the Japanese market. "The trade is looking for nice material, precision, and perfection,” Shahin said.
At the height of the global recession in 2008, Shahin became managing director of SR Trading, his older brother’s company. Japanese clients were looking for unusual and rare material that had become more popular in recent years, including grandidierite and benitoite. In 2012, Shahin transitioned to the Chinese market. His brother Ruzaik Aboosalih runs the business in Japan, specializing in padparadscha sapphire, Paraíba tourmaline, and other rare stones. Shahin sees great opportunity in China and Hong Kong. He has developed a very strong client base along with Cindy Xin Hao, who started out as his Chinese translator and has become a gem expert and managing partner of the Chinese business.

Figure 2. This rare blue-green beryl from Madagascar, weighing 10.19 ct, contains iron, chromium, and vanadium. Photo by Kevin Schumacher, courtesy of SR Trading.
Shahin thinks of China as a “young” market with consumers who are curious to see variety, more so than their traditional Japanese, European, and American counterparts. Here he targets almost every colored gemstone. His Chinese clients look for a wide variety of colored stones: corundum, emerald, and aquamarine and other beryls (see figure 2), as well as precious opal and tourmaline in its many colors. This gives Shahin opportunities to look for more stone varieties every day. Despite this market’s demand for a wide variety of gem material, gemological education is relatively new in China. Therefore, Shahin and Cindy conduct mini-seminars to groups of 10–15 people to teach them about gemology and the supply, demand, and value of colored stones. They also conduct gem mining and leisure tours in Sri Lanka for small groups from China. They educate the tourists about the process, from mining and cutting to the finished product.

Figure 3. A 2.95 ct grandidierite from Madagascar. Photo courtesy of SR Trading.
Shahin said that historically some of the finest corundum has come from Sri Lanka, but currently most sapphire is sourced from Madagascar. For other colored stones—such as grandidierite (figure 3), spinel, and Paraíba and other tourmalines—the main producers are mainly Brazil, Tanzania, Kenya, Congo, and India. Shahin buys stones from Hong Kong and Bangkok as well; such gems include spinel, rubies, mint-green garnets, and tanzanite (figure 4). Most of the time he buys faceted material, but as a perfectionist, he will recut 90% of his stones in Sri Lanka. He purchases all his stones, and they all undergo his personal inspection and quality control. His passion for his stones is what makes them easy to sell, because they are all very special to him. “I love them all,” he said.

Figure 4. A 22.6 ct precision cushion-cut deep blue tanzanite. Photo by Kevin Schumacher, courtesy of SR Trading.
Shahin sees plenty of opportunity for those who can bring value-added merchandise to the market. The global industry is looking for attractive, ethical, value-added gems. While it can be a struggle to find quality material—be it corundum, Paraíba tourmaline, spinel, or any other colored stone—it is worth it to work hard and be patient enough to find the right opportunity and source. Shahin notes, “With the experience and connections and what I’ve learned in the past 20 years, it helps to meet the right people and product to satisfy the demand. This demand will continue, and I see that as an opportunity to make business in the future.”

	Thoughts on the Chinese and Japanese Gem Markets @chapter:28


Publication Year: - Title: Cut: The 4th C Abstract: These three round brilliant diamonds, weighing 0.76, 0.82, and 0.74 ct (left to right), received Very Good cut grades. Each cut grade covers a range of proportions and can therefore have different appearances. Photo by Kevin Schumacher/GIA

	In an effort to establish standards for cut in the same manner as it has for color and clarity, GIA began issuing reports that included a cut grade for round brilliant diamonds in 2006. This grading system is based on research conducted over the previous decade, which was chronicled in several articles published in Gems & Gemology.

	GIA had been studying diamond cut for decades, when in 1989 the Institute turned a significant corner. It was at this time that new advances in computer technology allowed GIA researchers to analyze aspects of the visual appearance of round brilliant cut diamonds that once had been impractical and difficult to explore.

GIA developed an advanced ray-tracing program to understand how light interacts within a diamond. This helped researchers determine which proportion combinations create a brighter and more fiery appearance.

	Using advanced computer modeling, we were able to replicate the way light behaves within a round brilliant cut diamond so that we could predict how a diamond would perform with regard to brightness and fire. To study these two aspects of face-up appearance, we analyzed tens of thousands of proportion sets which included: table size, crown angle, pavilion angle, star length, lower-half length, girdle thickness, culet size, and total depth. We also studied the effects of polish and symmetry on appearance. We found that all of these parameters were interrelated in their effects on light performance, and contrary to some traditional thinking in the trade, that no single proportion, or subset of proportions, could be considered alone in judging diamond appearance. We found that there was a wide range of proportions that had the potential for high quality light performance.

	But that was just the beginning.

	The Questions Behind Cut

	We wanted to answer two important questions: First, to what degree do changes in proportion values create distinctions in appearance that can be seen by an observer? And second, which proportion sets produce results that are deemed attractive or unattractive by most observers?

	With extensive observations and research, we were able to answer these questions, and more.

	Development of the Cut Grading System

	The GIA Diamond Cut Grading System for round brilliant cut diamonds is a predictive system that is grounded in science and research.

	In an effort to validate the calculated values for brightness and fire, as well as analyze other components that contribute to a round brilliant's overall cut appearance and quality (such as scintillation, design, and craftsmanship), GIA embarked on an extensive journey of observation testing using a standardized lighting environment.

	Over 70,000 observations were made on more than 2,300 diamonds using observers from all sectors of the jewelry industry: diamond manufacturers, dealers, retailers, and jewelry consumers. This undertaking was, without a doubt, the largest study of this type ever conducted.

Observing real diamonds provided critical insight as to how the contrasting pattern of light and dark areas contributes to an attractive diamond.

	A Final, Predictive Grading System

	In our experiments, each observer was asked to evaluate the brightness, fire, and overall cut appearance of round brilliant diamonds representing many different proportion combinations. The results of this observation testing were vital to the development of the GIA Diamond Cut Grading System, and can be summarized as follows:

		We were able to validate our computer modeling for brightness and fire. This included refining our metrics so that the results represented the brightness and fire seen in actual diamonds when they were observed in standard lighting and viewing conditions.

		We were able to analyze and eventually predict other components of face-up appearance, such as scintillation, as well as aspects of cut quality such as design and craftsmanship.

		We were able to determine how much variation in any one component (for example, levels of brightness) observers could see consistently in actual diamonds, and how many overall cut grade categories people could consistently discern. The value of these results was immeasurable — they allowed us to transform our scientific models into a practical system that could be used in the day-to-day world of the diamond industry.

		We discovered that personal and regional preferences in appearance were an inherent part of a truly functional cut grading system. Although we confirmed that most observers could discern five overall grade categories for diamond cut quality, personal and/or regional tastes often dictated which diamond was finally preferred within each of those categories. This underscores the fact that there can be many different, yet equally pleasing, appearances within a grade category.

		Perhaps most importantly, extensive observation testing and trade interaction allowed GIA to create a diamond cut grading system that was predictive. That is, it assured us that when the complete set of proportion and parameter information is input into the system to obtain a cut grade, that grade is consistent with the grade that would have been provided by a large majority of observers. It is this predictive nature of the cut system that allowed GIA to create a cut database that contains cut grading results for over 38.5 million proportion combinations.

Thousands of diamonds were observed in a standardized lighting environment during the development of the GIA Diamond Cut Grading System.

	Putting It All Together

	Through computer modeling, observation testing, and trade interaction, we confirmed that to be attractive, a diamond should be bright, fiery, sparkling, and have a pleasing overall appearance, especially when the pattern of bright and dark areas is viewed face up.

	In the same manner, GIA recognized that more than just face-up attractiveness should be incorporated into the assessment of overall cut quality. Quality in design and craftsmanship (as evidenced by a diamond's weight ratio, durability, polish, and symmetry), even when face-up appearance is barely affected, should be considered in a diamond's final cut grade. @chapter:31


Publication Year: 2000 Title: Ametrine with Layers of Smoky Quartz Abstract: Two parallel zones of smoky quartz are evident in these three ametrine specimens (27.3–299.7 ct) from the new Yuruty mine in Bolivia. Photo courtesy Michael S. Krzemnicki, SSEF.

              Ametrine (amethyst-citrine) from Bolivia has been prevalent in the gem trade for many years (see, e.g., Gem News, Fall 1989, pp. 178–179, and Spring 1993, p. 53). At this year’s Tucson gem show, H. Marancenbaum of Steinmar Ltd. (Santa Cruz, Bolivia) kindly provided two rough fragments, three slightly polished crystals, and two fantasycut specimens of ametrine to the SSEF Swiss Gemmological Institute. Mr. Marancenbaum reported that these samples originated from the Yuruty mine, a new operation that is located in the same geologic unit (Murciélagos limestones) in Bolivia as the well-known Anahí mine (Vasconcelos et al., Gems & Gemology, Spring 1994, pp. 4–23).

An investigation of these Yuruty mine samples by the present contributor revealed an interesting new aspect to this bicolored quartz. In addition to the typical amethyst and citrine sectors (along the major and minor rhombohedral forms; again, see Vasconcelos et al., 1994), five of the samples also showed a similar pattern of two distinct layers of smoky quartz. These layers are oriented parallel to the minor rhombohedral form z {011 – 1}, within the citrine sector (see, e.g., figure 4). In the slightly polished crystals, the smoky layers were observed just below the surface. In this area, the color of both amethyst and citrine is rather pale. The two (broken) fragments that did not show smoky quartz layers were presumably derived from the central portion of a crystal; they did display more intense amethyst/citrine coloration.

The growth conditions of this unusual ametrine evidently facilitated the enhanced accommodation of aluminum impurities in the z sectors. Natural irradiation of these aluminum-rich zones would give rise to the smoky quartz color layers.

Approximately 30 tons of material have been produced at the Yuruty mine since February 1999, according to Mr. Marancenbaum. Large quantities of rough and cut amethyst, citrine, and ametrine from this new mine were available at this year’s Tucson show, and he anticipated that about 10,000 carats of cut material monthly could be expected in the near future. @chapter:4


Publication Year: - Title: The Unexpected Origins of Big Diamonds Abstract: 23.16 carat pink diamond unearthed from the Williamson Mine in Tanzania. Image courtesy of Petra Diamonds.

Dr. Evan Smith, Ph.D., GIA research scientist, has dedicated his work to methodically characterizing the inclusions found in rare diamonds. In this video presentation recorded at the 2017 JCK Las Vegas show, Smith shares his findings on the unexpected origins of big diamonds and what their characteristics tell us about the earth.
“Next time you look at a diamond, I hope you see it not only as a beautiful, valuable piece of gemstone; [you should also know that] diamonds are some of the most scientifically valuable samples of our earth,” Smith said. In this video, he explains that as diamonds form more than 100 miles below the earth’s surface, they often trap mineral inclusions that reveal the chemistry of the earth’s mantle.

Diamonds are some of the most scientifically valuable samples of our earth.
Dr. Evan Smith, GIA research scientist

Smith’s study on a 400 carat diamond found in Angola was the December 2016 cover story of Science magazine. Big diamonds such as this were the basis for his research in part because the origins of big stones are relatively unknown to scientists. He examined a variety of large, unique diamonds with similar characteristics. The diamonds were all similar to the Cullinan diamond, the largest gem quality diamond ever found. They were large and inclusion poor, typically without mineral inclusions; pure type IIa diamonds low in nitrogen; irregularly shaped and resorbed with surfaces rounded and dissolved. These characteristics gave rise to their name – CLIPPIR diamonds.

	Origins of Big Diamonds

An expert in diamond geology, Smith received his bachelor of applied science and master of engineering from Queen's University and a Ph.D. in geology from the University of British Columbia. He performed his postdoctoral research fellowship at GIA in 2015. @chapter:29


Publication Year: 2015 Title: Books: Collector’s Guide to the Zeolite Group Abstract: By Robert J. Lauf, softcover, 112 pp., publ. by Schiffer Books, Atglen, Pennsylvania, 2014, $19.99.

Collector’s Guide to the Zeolite Group is the 17th volume in the Schiffer Earth Science Monograph Series, and the 14th authored by Robert Lauf. Some of Lauf’s previous publications, including his work on beryl, garnet, and quartz, are of immediate interest to gemologists, while others, such as this book, may appeal more to mineralogists and geologists. Zeolites are a fascinating group of rock-forming minerals that are beloved by collectors, as they can form exceptional crystals and aggregates. Often lacking durability or distinctive beauty, they rarely appear as finished gemstones. As a working gemologist, I have only encountered a few zeolite minerals in the course of my education and everyday work: natrolite (as radial aggregates and a component of maw-sit-sit), pollucite, and thomsonite (fibrous aggregate).

Zeolites are structurally complex and are distinguished by their ability to exchange cations with surrounding solutions. They are immensely important for industrial purposes as sorbents, catalysts, and molecular sieves. While these minerals occur naturally, they are also produced as “designer” synthetics on a large scale. Over 200 “frameworks” of open cavities and channels formed by tetrahedral oxygen atoms surrounded by cations have been identified; of those, over 40 are natural occurrences. Zeolites are used in agriculture (animal feed, odor control, pet litter), horticulture (soil conditioners and growth media), and water purification. They are also act as carriers for pesticides and fungicides, and as gas and oil absorbents.

The introduction briefly discusses the research and literature on zeolites, citing a few detailed examples of use. Through cation change, naturally occurring cliniptolite can be used to filter radioactive cesium from wastewater at nuclear power plants.  Zeolites can be used as “molecular sieves” to separate molecules with differing cross sections (i.e. branched and unbranched hydrocarbons) in a vapor stream. The structure and morphology section tries to clearly lay out the structural chemistry and taxonomy of the group, but the book quickly goes beyond the scope of knowledge, comprehension, and expertise of the average gemologist or collector. The structural types are illustrated with diagrams that enhance the understanding of the unique framework structure and the functional “channels” and “cages.” The following chapter outlines zeolite’s formation and geochemistry, pointing out the environments where specimen-quality rough may be sourced, versus massive industrial-quality deposits.

The strength of the book is the alphabetized section on each type of zeolite, illustrated with superbly formed examples. The photography is also breathtakingly artistic. If the fascinating structure and utility of zeolites does not intrigue a budding collector, the pure aesthetics of the specimens surely will. Each entry describes locality information and associated minerals; a few include additional diagrams to illustrate the framework structure and different examples of crystal morphology.

The book concludes with a comprehensive and somewhat overwhelming list of references, but the reader is guided by the author’s annotations. Lauf also highlights a few resources of notable interest to those starting their own collection.

Like other books in the Earth Science Monograph Series, this volume is not a valuation guide, nor does it give an indication of the commonness or rarity of particular types of specimens. It serves as an excellent primer to the unique structure and function of this unique mineral group. In addition, the abundant high-quality illustrations of superb specimens will make this volume appealing even to an “armchair” mineral collector. @chapter:4


Publication Year: 2022 Title: Apatite Cluster in Zambian Emerald Abstract: An inclusion cluster consisting of a hexagonal prismatic apatite crystal and many rod- and bamboo-shaped crystals of apatite in a Zambian emerald. Photomicrograph by Ungkhana Atikarnsakul; field of view 3.60 mm.
This author recently studied a 1.68 ct faceted emerald containing several inclusions, including blocky fluid inclusions, transparent brownish crystals, needles, and particle clouds. These inclusions as well as the trace element chemistry supported a Zambian geographic origin. The emerald also exhibited elongated transparent crystals that resembled amphibole. In this case, Raman spectroscopy confirmed the mineral as apatite. Interestingly, this apatite formed a distinct inclusion cluster consisting of a large hexagonal prismatic crystal (a morphology typical of the mineral) associated with a multitude of rod- and bamboo-shaped crystals in various directions (see above). Other solid crystals observed in Zambian emerald include mica, actinolite (amphibole), quartz, zircon, and chromite.
Apatite, a common phosphate mineral, has previously been reported in various forms and in many other types of gems such as corundum, spinel, feldspar, and garnet, and it is not surprising to find it in emerald. However, this is the first time the author has encountered this fantastic form of apatite in emerald. @chapter:13


Publication Year: 2003 Title: Poudretteite: A Rare Gem Species from the Mogok Valley Abstract: In 2000, an unfamiliar gemstone was purchased in Mogok. It subsequently proved to be the rare borosilicate poudretteite, a mineral that previously had been identified only as tiny crystals from Mont Saint-Hilaire, Quebec, Canada. This article presents a complete gemological description of this unique gemstone and furthers the characterization of this mineral by advanced spectroscopic and chemical analytical techniques. @chapter:5


Publication Year: 2007 Title: From Single Source to Global Free Market: The Transformation of the Cultured Pearl Industry Abstract: Over the past 15 years a combination of market forces, environmental events, and scientific research has radically changed the cultured pearl industry from a single commodity dominated by one producer to a highly diverse industry operating throughout the Pacific region. The new products, consistent quality, and broader marketing programs in turn led major designers and retailers in the United States and Europe to take a much greater interest in cultured pearls. During this period, consumer interest has expanded from the traditional small and medium white round Japanese akoya cultured pearl to the larger South Sea and Tahitian goods, as well as numerous previously “undesirable” shapes and colors. @chapter:14


Publication Year: 1985 Title: Pink Diamonds from Australia Abstract: During the first few months of 1985, the New York office of the GIA Gem Trade Laboratory examined more than 150 gem-quality fancy pink diamonds, most of which had similar color, spectra, luminescence, color zoning, surface textures, and inclusions. This dramatic increase in the number of pink diamonds offered in the trade recently, along with the fact that a great majority exhibit similar physical properties, suggested a new source of pink diamonds. This observation, together with information received from several diamond dealers to the effect that pink diamonds had been recovered from the Australian deposits, suggests that most or all of the above-mentioned stones originated in Australia. This article reports on the gemological properties of these "new" pink diamonds and describes a number of characteristics that, seen in combination in a stone, are indicative of Australian origin. @chapter:20


Publication Year: 1988 Title: A Gem-Quality Iridescent Orthoamphibole from Wyoming Abstract: A gem-quality iridescent orthoamphibole from Wyoming, similar to that described from Greenland, has been identified. This ornamental material occurs in a weathered gneiss-schist, near its contact with a peridotite mass. Most of the individual iridescent grains that constitute this rock are golden or dark brown, but a few are rose red or silvery gray. They consist principally of goethite and/or opaline silica, which probably was derived directly from the original ferroanthophyllite as a result of weathering. Economic amounts of this material are not available at this time, although it is likely that the deposit has the potential to produce significant quantities. @chapter:1


Publication Year: 2019 Title: Second Annual Buccellati Award Winner Abstract: Ching-Hui Weng’s design, which won the second annual Buccellati Award, was inspired by the Urocissa caerulea bird, which is representative of her native Taiwan. The finished piece features white and yellow gold, white and yellow diamonds, opal, aquamarine, lapis lazuli, black chalcedony, and coral.
Ching-Hui Weng, a 2018 graduate of GIA’s Jewelry Design program in Taiwan, received the second annual Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design. One of 18 finalists from GIA’s seven schools, her winning design was a bird brooch (see above) featuring white and yellow gold, white and yellow diamonds, opal, aquamarine, lapis lazuli, black chalcedony, and coral. “My inspiration for this piece is the Urocissa caerulea, a blue bird that represents Taiwan,” said Weng. “The gemstones in this piece illustrate the bird’s fierce temperament and flight.”
Weng will travel to Italy to meet Mrs. Buccellati and view part of the foundation’s collection. She will also receive a plaque recognizing her achievement.
“We are pleased to congratulate Ms. Ching-Hui Weng, and look forward to welcoming her to Italy. Together with GIA, we hope to continue to encourage and support the dreams of young jewelry designers throughout the world,” said Larry French, chief officer of North America strategies for the Gianmaria Buccellati Foundation. “We know Gianmaria would have been proud to have his name on an event that celebrates, so beautifully, the art of jewelry design, the art that he loved so much.”
Submissions were presented as original, hand-rendered designs. Following several phases of judging, they were finally evaluated by a panel of industry experts. Weng was announced as the winner at the annual GIA alumni event held during the AGTA Gem Fair in Tucson.
The Gianmaria Buccellati Foundation sponsors the award to inspire beginning designers and honor the house’s founder. The 2019 award is now open to GIA Jewelry Design students who meet the eligibility requirements. @chapter:16


Publication Year: - Title: Copper-Bearing Minerals of Colorado Abstract: Between 1868 and 1922, Colorado produced almost 260 million pounds of copper. Nearly 100 million pounds came from the Leadville district, with another 50 million pounds mined in San Juan County (Henderson 1926). During the twentieth century, the Gilman district surpassed Leadville in total copper production with more than 210 million pounds mined (Beaty, Landis, and Thompson, 1990). Total Colorado production prior to 1958 reached 585 million pounds (Del Rio 1960). In this article 106 minerals from the Colorado Mineral Belt (COMB) are listed and 39 are discussed in the text. The Eagle mine in the Gilman District is probably Colorado’s most prolific producer of mineral specimens. Gilman pyrite, sphalerite, chalcopyrite, siderite, barite, and galena are found in collections all around the world. The Sweet Home mine in Buckskin Gulch, source of world-famous rodochrosite, is also well known for fine specimens of two copper-bearing minerals bornite and tetrahedrite. The Creede mining district is one of the best-studied mineral deposits and volcanic areas in the country. A detailed study of the Creede ore deposits has been made in an attempt to develop a model for epigenetic precious-metal deposits. Summitville is well known as the producer of the state’s finest covellite specimens. The Good Hope mine is the type locality for four copper-bearing tellurides: rickardite (Cu3-xTe2); weissite (Cu2-xTe); vulcanite (CuTe), and cameronite (AgCu7Te10). Turquoise was mined from the King mine deposit in Conejos County and from the Chief mine in the St. Kevin district, Lake County.

The state of Colorado has produced some significant copper-bearing mineral specimens. Most of the Colorado’s copper minerals are sulfides and sulfosalts with chalcopyrite being the most common copper-bearing mineral.

Abstracted by Guy Lalous @chapter:1


Publication Year: - Title: Rose Quartz History and Lore Abstract: Quartz crystals were valued by the ancient Egyptians as talismans with powers to prevent aging. - Bob Kammerling

                      Rose quartz beads dating back to 7000 BC have been found in the area once known as Mesopotamia (today’s Iraq). Rose quartz jewelry was known to be crafted by the Assyrians around 800-600 BC. The Assyrians, along with the Romans, might have been the first to use this stone.

People in the earliest recorded times believed in the magical powers of quartz. Ancient Roman, Egyptian, and Greek civilizations used quartz crystals as potent talismans. The Romans used rose quartz as a seal to signify ownership, and Egyptians believed the stone could prevent aging.

	The soft blush of rose quartz endeared the gem to early civilizations. Its rosy hue continues to appeal to modern jewelry lovers. – Bart Curren, courtesy Commercial Minerals
In the Middle Ages, medical practitioners used quartz in their healing potions. Early cultures of the Americas used quartz amulets. Known as the “love stone,” it was said to balance the emotions and to heal anger and disappointment.

	A quartz bead is the featured stone in this ancient Egyptian necklace. The strand
	consists of emerald, amethyst, and gold faience (a glazed ceramic). – Robert Weldon,
	on loan from the Royal Ontario Museum, Toronto, Canada @chapter:25


Publication Year: 2015 Title: Mexican Demantoid from New Deposits Abstract: Figure 1. Demantoid was recently discovered in Veracruz State, Mexico. The photo on the left shows an association of topazolite + demantoid. Demantoid crystals are seen in the photo on the right. Photos by Mikhail Ostrooumov.

	Gemologists have recognized three andradite varieties: melanite (black), topazolite (yellow-brown), and demantoid. Demantoid, the yellowish green to green variety, is the most important to the jeweler-gemologist. The traditional demantoid garnet sources are Russia (Ural Mountains) and Italy (Val Malenco and Sondrio). More than 20 years ago, small garnet crystals of pale yellowish green color were found in the Sonora andradite occurrence near the Mexican city of Hermosillo (Fall 1994 GNI, p. 194). This garnet has been classified as demantoid without any detailed gemological and mineralogical analysis.

	It is very interesting to note that in some deposits of metamorphic skarns (e.g., Kamchatka, Russia; Val Malenco, Italy; and Arizona, USA), the demantoid crystals are associated with topazolite (E.P. Kievlenko, Geology of Gems, Ocean Pictures, Littleton, Colorado, 2003). In late 2014, our investigations showed that the same mineralogical association (figure 1, left) is characteristic for the Las Vigas Mexican topazolite source (Fall 2014 GNI, pp. 246–247). These green to yellow-green garnet crystals, measuring 1.5–5.5 mm, are also hosted by the Las Vigas skarn deposits (Cerro de la Concordia, in Las Vigas de Ramirez municipality and the Piedra Parada mine in Tatatila municipality). These deposits are located in Veracruz State, about 50 km southeast of the town of Valle de Veracruz. Studying crystals from these two new Mexican deposits with different analytical techniques, the mineral was identified as demantoid garnet (figure 1, right).

	Three samples of rough demantoid (measuring 4.0–5.5 mm in the longest dimension) were characterized for this report, and the following gemological properties were determined: color—green; polariscope reaction—isotropic and weakly anisotropic; weak strain birefringence; RI—nα = 1.888–1.889; very strong dispersion, at 0.055 (visual indicator identification); hydrostatic SG—3.82–3.88; fluorescence—inert to both long- and short-wave UV radiation.

	The garnet composition was determined by means of electron microprobe analysis (EPMA), using a total of 15 analysis points. Standard conditions of 20 kV, 20 mA, and 1 µm beam size were used with a JEOL JSM-35c microprobe. The analyses showed little compositional heterogeneity or zonation. The structural formula was calculated on the basis of 12 oxygen atoms, yielding an average approximate composition of (Ca2.96 Fe2+0.08)3.04 Fe3+2.05 Si2.94O12. This structural formula has an abundance at the X-site and Y-site cations but is close to electroneutrality due to the sum of the positive and negative charges (Wc = +23.99; Wa = –24.00). The EPMA-WDS data showed that these green garnets were almost pure andradite (And 95.60 mol.%). No chromium was detected in the chemical composition of the studied crystals.

	Infrared transmission spectra were measured with a Bruker Tensor 27 FTIR spectrometer, scanning from 4000 to 400 cm–1 and using the KBr pellet method. The pellets were prepared by mixing approximately 3 mg of the sample with 300 mg KBr. OPUS software was used for the spectroscopic interpretation of the infrared spectra. Raman (figure 2, left), mid-infrared (figure 2, right) and X-ray analysis confirmed that the crystals belonged to the demantoid variety (http://rruff.info). The mid-IR spectra showed the presence of hydroxyl groups. The infrared spectra consisted of a prominent band at 3420 cm–1, with a secondary band at about 3610 cm–1 due to the fundamental OH stretching vibration of water molecules, as well as the water bending vibration at approximately 1650 cm–1.

	Figure 2. Raman (left) and infrared (right) spectra of the samples confirm their demantoid garnet identity.

	UV-Vis-NIR spectroscopy showed absorption bands at 403, 444, 574, 617, 854, and 1170 nm, which can be assigned to spin-forbidden crystal-field transition of Fe3+, substituted on the octahedral Al3+ site of the garnet structure. Our EPMA analyses of garnet generally indicated the presence of some divalent iron. The spectra showed absorption bands in the 900–1000 nm and 1150–1250 nm ranges, which are assigned to Fe2+, and corresponding absorption features were observed at about 860 and 1170 nm. The simultaneous presence of both Fe3+ and Fe2+ means that intervalence charge transfer is possible (in accordance with A.S. Marfunin, Advanced Mineralogy, Vol. 2, Springer-Verlag, Berlin, 1995, pp. 113–114), and the 574 nm band is therefore assigned to an Fe2+→Fe3+ intervalence charge transfer band. The typical absorption bands of Cr3+ in the visible region between 630 and 690 nm are absent, consistent with the EPMA results. Our investigations have also shown that some demantoid garnets from Russia do not show any chromium absorption, and their color is due to the presence of Fe3+ alone.

	The color measuring system of the International Commission of Illumination (ICI) has been found useful for describing the color characteristics of minerals (K. Langer et al., “Optical absorption spectroscopy,” in A.S. Marfunin, Ed., Advanced Mineralogy, Vol. 2, Springer-Verlag, Berlin, 1995, pp. 119–122). The color of a mineral is assigned to a point in the x-y coordinates of the ICI color chart. Special computer programs are used to calculate the color parameters (x-y coordinates, λ—dominant wavelength, P—saturation or purity, Y—lightness) of a mineral directly from the measured optical absorption spectrum. The dominant wavelength λ, or hue, is the human eye’s psycho-sensory interpretation of wavelengths that are identified by the x-y coordinates of the ICI color chart. Preliminary colorimetric calculations showed that the colors of the Mexican demantoid have low saturation (P=20%) and lightness (Y=17%). Therefore, they are darker than pure green demantoid from other deposits (e.g., Bobrovka River in the Ural Mountains). The dominant wavelength of Mexican demantoid (λ=560 nm) is a slightly yellowish green. This combination of colorimetric parameters defines a color different from that of chromium-bearing demantoid. Measurements on the demantoid from the Urals showed higher values of saturation (P=44–50) and lightness (Y=20–37%) and a purer green hue, with λ=530–545 nm (M. Ostrooumov, “Colorimetry of minerals,” Priroda, No. 6, 1987, pp. 43–53, in Russian). Such demantoids are more attractive to the gem trade.

	Thus, electron microprobe (EPMA-WDS) chemical analyses, various spectroscopic techniques, X-ray diffraction, and standard gemological testing have confirmed the discovery of demantoid in the Las Vigas skarn deposits of Veracruz State. The discovery could represent an interesting mineralogical and gemological opportunity. Although the full range and economic potential of this demantoid has not been determined, it may well have features that distinguish it from other important deposits worldwide. @chapter:5


Publication Year: 2013 Title: Canadian Mining Industry: Taking a Step Up with Range of Operations Abstract: The expansion of various mining projects in Canada’s North (Northwest Territories, Yukon, and Nunavut) is set to lead the country in economic growth over the next two years. Spinoff activity is also expected to increase, based on pending mines in the assessment phase or preproduction stage, further boosting employment and local economic development. Production in these areas is expected to last well into the coming decades. Environmental groups and local residents are also interested in the impact on the Canadian North ecosystem as well as the long-term effects on the towns and industry when the boom is over.

Abstracted by Michele Kelley @chapter:24


Publication Year: - Title: Fall 2015 G&G: Trapiche Emeralds, Synthetic Diamonds and a Large Diamond Source Abstract: The lead article in this issue is an in-depth study on the geological formation and growth of Colombian trapiche emeralds. The cover photo shows a 58.83 ct. crystal specimen (left) and a 22.74 ct. cabochon (right), both displaying the material’s signature six-rayed pattern, from the renowned Peñas Blancas emerald region. The host rock, seen in the background, is carbonaceous shale containing veins of calcite, pyrite and minute crystals of low-grade emerald. Photo by Robert Weldon/GIA, courtesy of Jose Guillermo Ortiz and Colombian Emeralds Company, Bogota.

A report on Colombia’s unique trapiche emeralds is the cover feature of the fall 2015 issue of Gems & Gemology (G&G), which also offers an analysis of large synthetic diamonds produced in Russia and a detailed look inside the Letšeng Diamond Mine in Lesotho (the leading source for mega-sized diamonds).
Colombian Trapiche Emeralds: Recent Advances in Understanding Their Formation

Colombia’s trapiche emeralds show a distinct pattern that resembles a wheel with six spokes. They are found only in the black shales of the country’s western emerald zone near the legendary mines of Muzo, Quiopama and Coscuez.

These trapiche emeralds, all from Peñas Blancas, range from 5.09 to 22.74 carats. Photo by Robert Weldon/GIA. Courtesy of Jose Guillermo Ortiz, Colombian Emerald Co.
The researchers, Dr. Isabella Pignatelli, Gaston Giuliani, Daniel Ohnenstetter, Giovanna Agrosì, Sandrine Mathieu, Christophe Morlot and Yannick Branquet, performed spectroscopic and chemical analyses on the samples to determine how they formed within their geological setting. They determined that super-pressurized fluid within the black shale helped grow the emerald seed crystals and provided a unique growth environment for them to form into trapiches.
Large Colorless HPHT-Grown Synthetic Gem Diamonds from New Diamond Technology, Russia

In the past five years, the vast majority of synthetic diamonds appearing in the gem market have been manufactured by the Chemical Vapor Deposition (CVD) process, which has been viewed as more efficient than the older High Pressure, High Temperature (HPHT) method, especially for colorless stones.

A Russian manufacturer, New Diamond Technologies, however, has introduced a line of large HPHT grown colorless synthetics and offered 44 samples to GIA for analysis.

As-grown HPHT diamond single crystals produced using a simple Fe-based solvent with Al as a nitrogen getter. The sample on the far right is the largest, weighing 1.40 ct. Photo courtesy of New Diamond Technology.
GIA researchers Ulrika F.S. D’Haenens-Johansson, Andrey Katrusha, Kyaw Soe Moe, Paul Johnson, and Wuyi Wang analyzed the samples using a combination of spectroscopic and gemological techniques to characterize the quality of the material and determine the means of distinguishing them from natural, treated and alternative laboratory-grown diamonds.

These samples had weights ranging from 0.20 to 5.11 carats, color grades from D to K, and clarity grades from IF to I2. Importantly, 89% were classified as colorless (D-F), demonstrating that HPHT growth methods can be used to routinely achieve these color grades.
Letšeng’s Unique Diamond Proposition

The Letšeng-la-Terae diamond mine in Lesotho is the world’s most consistent source of type IIa diamonds (those with exceptionally low nitrogen content), which account for about one-fourth of its production. The mine claims six of the 20 largest diamonds ever discovered: 478, 493, 527, 550, 601 and 603 carats. The largest of these, the Lesotho Promise, was found in 2006 and sold to London jeweler Laurence Graff for $12.4 million.

This remote village, deep in the Maloti Mountains near the Letšeng mine, is primarily dedicated to agriculture and sheep herding. Villagers also form the workforce for the diamond mine. Basuto ponies, such as the one seen here, are esteemed for their speed and surefootedness in the steep, rocky mountain passes. Photo by Robert Weldon/GIA.
The report by Russell Shor, Robert Weldon, A.J.A. (Bram) Janse, Christopher M. Breeding and Steven B. Shirey, also notes that Letšeng’s diamonds are unusual in that a majority are dodecahedral in form, which are very rare in other sources. Despite its bounty, Letšeng has had a difficult history because its ore grade is extremely low – about 2 carats per 100 tonnes and was not economic until recovery technology and diamond prices improved to allow profitable operation.
Origin Determination of Dolomite-Related White Nephrite through Iterative-Binary Linear Discriminant Analysis

Determining the origin of nephrite jade always has been difficult using standard gemological properties and observations. The authors, Zemin Luo, Mingxing Yang and Andy H. Shen, sampled nephrite jade from eight different dolomite-related deposits in eastern Asia.

This ancient pendant was discovered in the tomb of Marquis Yi, ruler of Zeng State during the Warring States period (ca. 475–221 BC). © Hubei Provincial Museum.
The authors used a new statistical analysis method based on linear discriminant analysis (LDA) and trace-element data from laser ablation−inductively coupled plasma–mass spectrometry (LA-ICP-MS), to achieve significantly improved origin determination (an average of 94.4% accuracy) for these nephrite samples. This technique could be applied to other gemstones to determine their geographic origins.
Lab Notes

This section of G&G features a discussion on unusual graining structure in a very light pink diamond with a uniform color plane intersecting with a cone of strain that fit perfectly into a colorless hole; an HPHT treated yellow diamond whose treatment was discovered by spectroscopic analysis; and an emerald with strong color zoning along the pavilion facets that demonstrates the importance of proper orientation and cutting. Other lab notes include a look at irradiated green-blue CVD synthetic diamonds that are the product of new growth technology; a natural green jadeite carving with areas that had been dyed green; and an examination of three large, natural abalone pearls.

Three unique abalone pearls are shown alongside a typical 12 mm golden South Sea bead-cultured pearl for comparison.
Micro-World

The Micro World section shows a Fancy Intense purplish pink diamond with an intricate geometric pattern of planar cracks and strain-induced bodycolor; an otherwise colorless rough diamond that has an eye-visible bluish-green stain near the surface caused by radiation; blue octahedral crystal inclusions within helidor cabochons that are determined to be gahnite, a rare zinc-rich member of the spinel group; and a trapiche pezzottite reportedly found near the Thai-Myanmar border.

Between crossed polars the diamond shows high-order interference colors consistent with the strain causing the cleavage network along the octahedral planes. Photomicrograph by Jonathan Muyal; field of view 0.62 mm.
Other features in this section include glassy melt inclusions in alluvial Montana sapphires, molybdenite inclusions in colorless topaz, and a lighting technique from gemological microscopy, Modified Rheinberg Illumination, that provides false-color contrast to enhance inclusion scenes. @chapter:2