Publish Year: - Title: De Beers Reduces RoughPrices – Too Little? Abstract: De Beers lowered the prices of rough diamonds at its May sight, but the debate over how much to cut continues: Some say more reductions are needed, while others claim they would compromise the values of their inventories. Courtesy of De Beers

                      De Beers apparently heard its clients and reduced the prices and quantities of rough diamonds it offered at the May 4-8 sight. The price cut was an average of 3%, concentrated mainly in the better qualities, while the cost of goods destined for the U.S. mass market remained relatively unchanged.

The May sight totaled about $450 million, according to reports – way down from the $690 million of the March sight (there was no April sight) when clients walked away from an estimated 30-40% of their allocations because they were not profitable to cut and financing was expensive and difficult to come by. The refusal rate of the May sight, the first of the new 30-month term, was reportedly below 10%.

Diamond manufacturers had mixed views on the sight. Some believe the adjustment from De Beers was inadequate, noting that polished prices declined much more than 3% since the beginning of the year. The squeeze remains because polished prices have slipped much more than that since January. Others point out that lowering rough prices too much will compromise the value of existing rough inventories, further reducing sightholders’ available credit.

Alrosa reportedly will lower prices by a similar amount at its next sale in late May.

Diamonds Treatments Keep Evolving

In 1999 GIA embarked on a crash research program to detect natural diamonds that had been treated by the high pressure, high temperature (HPHT) to improve their color after they were introduced into the marketplace. On May 12, GIA informed the trade that approximately 500 colorless to near-colorless diamonds submitted to its Ramat Gan grading laboratory had potentially been subjected to an undisclosed temporary treatment. The Institute notified the appropriate trade bodies, terminated client agreements with several diamond firms that had submitted the stones in question, and posted the report numbers of the potentially treated stones.

The World Federation of Diamond Bourses and other trade organizations can impose sanctions, including fines and expulsion from member diamond bourses, on dealers who intentionally attempt to sell treated or synthetic diamonds without disclosure.

More Diamond News

Blue Nile, the leading online diamond seller, reported that its first quarter diamond sales fell short of its goal, coming in just 2.6% higher than the comparable period last year. The company had been reporting double-digit growth for much of its 15-year existence. A sharp decline in high ticket sales, especially those over $50,000, was responsible for the sales short fall, the company said. Blue Nile reported that its engagement ring business − its mainstay − was flat for the quarter, but that fashion jewelry and international sales did see an upturn.

Auctions

More price records fell again with Sotheby’s May 12 Geneva Magnificent Jewelry auction, which totaled more than $160.9 million, the highest total ever achieved for a jewelry sale. The highlight was the 25.59 carat (ct.) “Sunrise Ruby” by Cartier that drew a winning bid of $30.38 million – nearly $1.2 million per carat and nearly twice its pre-sale estimate. The Burmese ruby was unheated and commanded the highest price for a ruby ever achieved at auction.

Other notable sales at the May 12 Sotheby’s auction included:

		An 8.72 ct. GIA-graded Fancy Vivid pink diamond believed to have belonged to Princess Mathilde, the niece of Napoleon Bonaparte, which old for just over $16 million; about $1.8 million per carat.

		A natural pearl strand containing 78 pearls and a 4.39 ct. marquise shape diamond that went for just under $7 million.

		A 30.23 ct. Kashmir sapphire set by Cartier with 42.35 carats of diamonds, which drew a top bid of $6.1 million.

The following day, also in Geneva, Christies’ sale realized $97 million. The top lot was a 5.18 ct. GIA-graded Fancy Vivid pink diamond that sold for $10.7 million, or just over $2 million per carat. In addition, a 35.09 ct. cushion shape Kashmir sapphire sold for $7.35 million, or $209,689 per carat, a record price for a gem from that region.

An Asian buyer purchased a 55.52 ct. GIA-graded D IF pear shape diamond for $9 million, $162,000 per carat, while a single strand of 19th century natural pearl necklace sold to a dealer for $3.9 million. The pearls ranged from 7.8 mm to 11 mm.

Sotheby’s April 21 auction in New York was highlighted by the sale of a 100.2 ct. GIA-graded Type IIa D IF cut-cornered rectangular shape diamond that sold for $22 million ($220,000 per carat), square in the middle of its pre-sale estimate. This was a strong price in light of the pressures on top gems and other luxury items this year. In addition, a Type IIa 22.3 ct. marquise shape D IF diamond sold for $3.3 million (about $150,000 per carat). @topic:7


Publish Year: - Title: GIA Tests Extraterrestrial Gemstones for Down-to-Earth Elements Abstract: This gold pendant is mounted with polished extraterrestrial peridot over mother-of-pearl. Photo by GIA/Robert Weldon.

                      While scientists speculate about diamond planets hurtling through the galaxy, at least one extraterrestrial gemstone is already among us.

Peridot, an olive-green gem also found here on Earth, has been recovered from meteorites on occasion, and even faceted into gemstones, though specimens are so rare that you’re unlikely to find them in a jeweler’s showcase. But researchers at GIA (Gemological Institute of America) assembled 26 extraterrestrial samples to discover the differences between them and their earthly counterparts. The findings are reported in GIA’s Gems & Gemology’s Fall 2011 issue.

Peridot is the gem version of a mineral called olivine, an iron and magnesium silicate -- (i.e. containing silicon). Olivine is part of the makeup of our solar system neighbors, including some metallic meteorites that occasionally fall on our home planet. While such peridot-bearing meteorites are rare enough, the intense heat from their journey to Earth and their explosive impact on contact with terra firma ensure that few specimens survive intact. That’s why peridot pieces from outer space are nearly always quite small.

Peridot from Earth’s own deposits was one of the first gemstones treasured by mankind. The ancient Egyptians called it “the gem of the sun” after discovering a deposit in what’s now known as St. John’s Island in the Red Sea. Today, sources include the United States (Arizona, Texas and Hawaii), China, Myanmar and Pakistan, which produces many of the largest, finest specimens. Peridot’s attractive color and relatively modest price have made it popular with jewelry designers around the world.

GIA researchers Dr. Andy Shen, John Koivula and Dr. James Shigley assembled specimens from several terrestrial locales and compared them with 26 samples taken from the Esquel meteorite, the most notable peridot-bearing extraterrestrial object.

Discovered in Argentina about 50 years ago, this massive meteorite contained numerous peridot crystals. An American collector purchased most of the Esquel in 1992 and divided it into a number of sections for sale. Three of the Esquel samples examined by GIA were faceted gemstones, while the others were part of polished slabs.

Using a laser beam and sophisticated mass spectrometry that can detect tiny amounts of elements within gemstones, the GIA team discovered significant differences between earthly and extraterrestrial peridot. Their tests found different levels of lithium, vanadium, nickel, manganese, cobalt and zinc between the two, allowing researchers and ultimately gem buyers to confidently distinguish between peridot of different worlds.

	A section of the translucent Esquel meteorite reveals a kaleidoscope of peridot crystals from outer space. Courtesy of Robert A. Haag; photo by GIA/Robert Weldon.

	This richly colored 1.12 carat extraterrestrial peridot was extracted from the massive Esquel meteorite, a polished section of which rests behind it. Courtesy of Robert A. Haag; photo by GIA/Robert Weldon. @topic:2


Publish Year: 2009 Title: The French Blue and the Hope: New Data from the Discovery of a Historical Lead Cast Abstract: A lead cast of the French Blue diamond, a mythic item in the French Crown Jewels, was recently found in the mineral collection of the Muséum National d’Histoire Naturelle (MNHN) in Paris. The details of this diamond—stolen in 1792 during the French Revolution—have up to now been known only from a drawing of an insignia of the Golden Fleece belonging to King Louis XV that was published in 1889 and, more recently, from an unpublished rendering dated as early as 1749. Computer modeling of the French Blue from a laser scan of the lead cast revealed details of the cut that could not be inferred from these drawings. Models of both the lead cast and the Hope diamond confirm that the latter could have been recut from the French Blue. The additional discovery of the catalog entry associated with the lead cast at the MNHN suggests that Henry Philip Hope may have owned the French Blue diamond after its 1792 theft and before it was recut. @topic:10


Publish Year: - Title: John King Abstract: Diamond grading is both a science and an art, requiring attention to detail and recognition of the uniqueness of each stone. Perhaps this is why John King, GIA’s chief quality officer since 2008 and an acclaimed artist in his own right, has achieved worldwide recognition for his trailblazing work in the field of colored diamonds.

After obtaining a BFA at Wayne State University and an MFA at Hunter College, King began his career at the Institute as a diamond grader, earning his GG in 1979. His academic focus on color theory, color naming, and order systems influenced his later work as a laboratory project officer on grading some of the world’s most famous colored diamonds, including the legendary Hope at the Smithsonian Institution (1988) and the Centenary, the largest D-color Flawless or Internally Flawless diamond seen at the time of its grading (1994). He was named GIA’s Staff Member of the Year in 1993, one year prior to becoming the lab’s project officer.

During the 1990s, King’s eye for color and grading expertise led to his work in refining and revising the terminology used for colored diamond grading reports issued by GIA. His work led to the publication of several groundbreaking articles on colored diamond characteristics and grading factors, including those pertaining specifically to blue, pink, and yellow material. Of his many published articles, nine have received G&G’s Most Valuable Article award. He also served as editor of G&G in Review: Colored Diamonds (2006), a compilation of the journal’s most notable articles on the  topic. Additionally, King has acted as an ambassador on GIA’s behalf, lecturing extensively on topics relating to colored diamonds, laboratory grading, and gemological research.

Outside of his work at the Institute, King is a widely respected artist, working in various mediums. For nearly three decades, he has shown his work at exhibitions held around the world, including at the Library of Congress, the Brooklyn Museum, and the Vicenza Art Fair (Italy), making clear that his eye for beauty translates outside of the gemological laboratory. King has been awarded both the NEA Fellowship Grant and the Pollock-Krasner Foundation grant for his artistic endeavors. His experience in both the lab setting and the art studio has helped pave the way to a greater understanding and wider appreciation for colored diamonds. @topic:10


Publish Year: 2014 Title: A Fitting Conclusion to Our 80th Anniversary Abstract: Welcome to the final issue of G&G’s 80th anniversary! Topics we’ve covered thus far include the Chinese and Sri Lankan gem and jewelry industries, beneficiation through Botswana’s diamond industry, three-phase inclusions in emerald, HPHT synthetic diamonds, Myanmar’s remarkable “Jedi” spinel, and pleochroism in colored gems.

In this Winter 2014 issue, three of our four articles focus on aspects of diamond. I was privileged to see the subject of one these papers up close: the Blue Moon diamond, prior to its exhibition at the Natural History Museum of Los Angeles County. This spectacular gem was recovered from the Cullinan mine—formerly a De Beers operation—in early 2014. As such, it’s a piece of the story told in our first two articles, which respectively survey recent changes in rough diamond distribution with the growth of the auction system and review the Argyle mine’s exclusive pink diamond tenders, held annually since 1985.

Our lead article, by GIA senior industry analyst Russell Shor, discusses the sweeping changes brought to rough diamond pricing and supply through the adoption of tenders and live auctions by leading producers. He explains that current opinion is divided: Some advocate auctions as a more accurate reflection of rough diamond market values, while others fear they encourage volatility of prices and speculation.

Our second paper, by the GIA laboratory’s John King, Dr. Jim Shigley, and Claudia Jannucci, is a very timely one. The fall of 2014 marked the 30th edition of Argyle’s pink diamond tenders, the invitation-only auctions of the mine’s most prized gems. This paper offers an insightful review of each auction to date. Over the years, GIA has been in the fortunate position to grade these premium pink to red diamonds, and this article also presents a concise survey of the color, carat weight, and cutting style of the gems offered.

Next, Dr. Eloïse Gaillou of the Paris School of Mines, Dr. Jeffrey Post of the Smithsonian Institution, and their coauthors present a rare gemological study of the 12.03 ct Blue Moon diamond. Prior to its fashioning, this Fancy Vivid blue, internally flawless diamond set a record price for a rough gem, bringing US$25.6 million in early 2014.

In our final article, Dr. Le Thi-Thu Huong from the Hanoi University of Science and her coauthors deliver a preliminary study—contrasting FTIR and Raman spectrometry—on the topic of separating natural and synthetic emeralds using vibrational spectroscopy.

In addition to these four feature articles, you’ll find our regular Lab Notes and Gem News International sections. We’ve gathered a variety of GNI contributions in the winter issue, including entries on the first non-nacreous beaded cultured pearl described so far, a new Ethiopian black opal deposit, a beryl and topaz doublet set in fine jewelry, and demantoid garnet from a new deposit in Pakistan’s Baluchistan province. This last entry is coauthored by one of GIA’s new postdoctoral research associates, Dr. Aaron Palke. We’re also delighted to publish a letter from distinguished gemologist Dr. Karl Schmetzer offering comment on the summer edition’s emerald inclusion article.

As another year begins, we hope you find this issue a fitting conclusion to our 80th anniversary! @topic:12


Publish Year: 1997 Title: Summer 1997 G&G Book Reviews Abstract: “Cameos in Context The Benjamin Zucker Lectures, 1990”
Edited by Martin Henig and Michael Vickers, 102 pp., illus., publ. by The
Ashmolean Museum, Oxford, England, and Derek J. Content, Inc., Houlton, Maine, 1993, £27.50 (about US$46.00)

“Gemstones of North America, Volume III”
By John Sinkankas, 527 pp., illus., publ. by Geoscience Press, Tucson, AZ, 1997. US$65.00

“Diamond Exploration Techniques Emphasising Indicator Mineral Geochemistry and Canadian Examples”
By C. E. Fipke, J. J. Gurney, and R. O. Moore, 86 pp., illus., Geological Survey of Canada Bulletin No. 423, Ottawa, Ontario, Canada, 1995, Can$24.85

“An Overview of Production of Specific U.S. Gemstones”
By Gordon Austin, 41 pp., illus., Special Publication 14-95, U.S. Department of the Interior, U.S. Bureau of Mines, 1995, US$5.50

“Gemmologia Europa V—European Gemmologists on Rubies and Sapphires”
Edited by Margherita Superchi, 141 pp., illus, publ. by CISGEM, Milan, Italy, 1996, 35,000 lira (about US$20.00)

To view the full section, download the PDF above. @topic:8


Publish Year: 1994 Title: Fall 1994 G&G Book Reviews Abstract: “Diamonds”
By Fred Ward, 64 pp., illus., publ. by Gem Book Publishers, Bethesda, MD, 1993. US$14.95

“Streeter of Bond Street: A Victorian Jeweller”
By Patrick Streeter, 174 pp., illus., publ. by Matching Press, Harlow, England, 1993. US$30.00

“Beads of the World”
By Peter Francis, Jr., 142 pp., illus., publ. by Schiffer Publishing, Ltd., Atglen, PA, 1994. US$19.95

To view the full section, download the PDF above. @topic:6


Publish Year: 1993 Title: Winter 1993 G&G Book Reviews Abstract: “Gemology, an Annotated Bibliography”
By John Sinkankas, 2 vols., 1200 pp., illus., publ. by Scarecrow Press, Metuchen, NJ, and London, 1993. US$179.50, regular edition, $250.00, limited edition

“Opal Adventures”
By Paul Downing, 234 pp., illus., publ. by Majestic Gems & Carvings, Tallahassee, FL, 1990. US$19.95

“Diamond Mine”
By Peter Read, 188 pp., publ. by Book Guild, Sussex, England, 1992. US$24.95

“Practical Uses of Diamond”
By Andrzej Bukon' and Andzej Szyman'ski, translated by Jerzy Tomaszczyk, 248 pp., illus., available from and publ. by Ellis Horwood and Polish Scientific Publishers PWN, West Sussex,
England, 1993.

“Mineraux Passion (Mineral Passion [in French])”
By Pierre and Nelly Bariand, 223 pp., illus., publ. by Bordas, Paris, France, 1992.

To view the full section, download the PDF above. @topic:8


Publish Year: 1981 Title: Cubic Zirconia: An Update Abstract: Soon after it was first marketed in 1976, colorless cubic zirconia became the dominant diamond imitation, with current production of approximately 60 million carats per year. Although cubic zirconia was discovered as a natural mineral in 1937, crystals usable for faceting were first produced in 1969 and it was not until a practical skull-melting technique was developed in the USSR in 1972 that commercial production became feasible. This article reviews the skull-melting technique used to produce cubic zirconia and examines the current status of this diamond simulant with regard to quality, production, and market. The patent situation is discussed, as well as prospects for new diamond imitations and the recent surge of interest in colored cubic zirconia. Also included is an Appendix summarizing the technical and gemological data for cubic zirconia and its distinguishing characteristics. @topic:10


Publish Year: - Title: Summer 2010 G&G Book Reviews Abstract: “American Luxury: Jewels from the House of Tiffany”
Edited by Jeannine Falino and Yvonne J. Markowitz, 207 pp., illus., publ. by Antique Collectors Club [www.antique-acc.com], Woodbridge, Suffolk, UK, 2009. US$65.00

“Gemstones”
By Karen Hurrell and Mary L. Johnson, 319 pp., illus., publ. by Metro Books [www.barnesandnoble.com], New York, 2008. US$12.98

“Diamonds: The Quest from Solid Rock to the Magic of Diamonds”
By Christine Gordon, 430 pp., illus., publ. by Tectum Publishers, Antwerp, 2008. US$135

“Schiffer Earth Science Monographs”
Publ. by Schiffer Publishing [www.schifferbooks.com], Atglen, PA, 2008–2009. US$19.90 each

“Minéraux Remarquables”
By Jean-Claude Boulliar with photography by Orso Martinelli, 252 pp., illus., publ. by Plage [plage2@wanaadoo.fr], Paris, 2009, €69 [in French and English]

To view the full section, download the PDF above. @topic:6


Publish Year: - Title: Banks Move to Curb Rough Speculation Abstract: Rough diamond crystal. Photo courtesy of De Beers.

	The leading diamond banks have moved to dampen speculative rough buying in their latest round of credit cutbacks. Banks will only finance 70% of client rough purchases, instead of fully funding them.

	The banks believe rough prices have soared far beyond those of comparable polished diamonds, making diamond cutting unprofitable and creating a liquidity crisis throughout the industry.  At the same time, they have further reduced lending across the board by another 10%, lowering it to 65-70% of  client receivables.

	Banks, which had supported the diamond industry through the economic crisis of 2008-9, say credit reductions are necessary to bring rough prices and manufacturing activities more in line with  market forces. By some estimates, manufacturing significantly exceeded demand for some sizes and qualities, sometimes resulting in large, unbalanced inventories.

	The credit reductions have hit most diamond manufacturers, but they do applaud measures to reduce the growing gap between rough and polished prices. The International Diamond Manufacturers Association issued a call on Oct 10 to diamond mining companies asking them “to face reality” and rein-in the out-of-control speculative rough buying.

	The banks’ action puts De Beers and other diamond producers in the middle because, while manufacturers have been buying very cautiously, some rough dealers have been paying the higher prices, which has kept prices high.

	De Beers’ sightholders, for example, have been leaving 10-15% of their allocations on the table for much of this year. De Beers executives have reportedly stated that a client’s “purchase history” will be reviewed in their applications for the next sight term that begins in 2015. De Beers and other producers have not significantly lowered rough prices despite the stagnant state of polished prices.  Additionally, De Beers’ executives, according to press reports, have told clients who complain about high rough prices that other clients would be happy to pay their prices for rough.

	Russia’s Alrosa and Rio Tinto also have been reluctant to lower prices, particularly as the former is in the midst of an initial public offering and the latter is funding an extremely costly retooling of its Argyle mine. Tender sale prices have also held up, but some analysts believe speculative dealers have been leading the bidding.

	Whether the banks’ actions help bring rough prices more in line with the polished market will become apparent by year’s end.

SYNTHETIC DIAMONDS: Recent reports of undisclosed synthetic diamonds mixed into parcels of natural diamonds have rattled the industry. Several manufacturers of natural diamonds in Surat have allegedly begun to grow CVD synthetics; press reports indicate that synthetics from existing producers have been showing up in parcels.

	GIA has seen no significant increase in the number of synthetics submitted to its laboratory for grading. According to the press reports, most of the undisclosed activity appears to be concentrated in the melee and small stones that generally are not submitted to gemological labs for grading. @topic:7


Publish Year: - Title: Botswana: Making Beneficiation Work Abstract: SAFDICO specializes in large, precision-cuts. Managing director Rutang Moses (right) confers with her factory manager and a diamond polisher.

		Rutang Moses, director of the South African Diamond Corporation’s (SAFDICO) Botswana diamond manufacturing operation, unwraps a five-carat round brilliant diamond from its gem paper and rocks it in the light so the fire can play.

		“We do precision cuts here,” she says. “It’s taken us awhile to build the expertise locally because our company can never compromise its standards. But we have done it ‒ almost all from scratch.” The company has replaced most of its foreign workers with locals, including Moses, who is the first Motswana (native of Botswana) to manage a diamond operation.

		SAFDICO’s diamond manufacturing plant is located in the new Diamond Technology Park, located between the airport and Botswana’s capital Gaborone. ‘High-tech’ is the phrase to describe SAFDICO’s diamond operation: computer-driven rough planners, laser bruters and robotic polishing machines.

		And SAFDICO is only one of more than 20 such technology-driven diamond operations located in and around the Technology Park, which opened in 2010. Today, nearly 3,000 workers in Botswana are cutting and polishing diamonds to export ‒ at close to $800 million in revenue last year and closing in on the $1 billion mark by 2015. Not all of the polishing operations are profitable, but many are and others have made great strides toward that goal.

		Such was not the case more than 20 years ago when De Beers opened the first diamond cutting factory in Botswana. Some executives of the company were skeptical at first. They believed cutting diamonds in Africa was too expensive to compete with India or an emerging China, and that the business was too far removed from world markets to make it viable.

		Nevertheless, the government insisted, noting that it wanted its chief resource – diamonds – to bring more employment and value to the country’s economy.

		Today, that diamond factory, Teemane (which means “diamond” in the local language) is still flourishing, albeit with new owners; 24 other factories are up and running as well. What has made the difference?

		First, technology. The past two decades have brought a technological revolution in diamond cutting with the machines described above that have halved processing time and increased both quality of make and yield from the rough. As a result, manufacturers say the profit threshold for manufacturing in Botswana has fallen from 1 carat in 2000 to 0.40 carats today for companies that invested in the new technology.

		This technology does not come cheap. A large diamond manufacturing operation can cost $7 - $10 million to start up and get running. Then there are the costs of training local technicians to operate, calibrate and maintain the extremely sophisticated equipment.

		Second, is because they’ve had to. Botswana is the world’s largest diamond producer by value (about $4 billion last year. The government also owns a 15% stake in De Beers. Seven years ago, as part of a new partnership agreement, the government required De Beers to move most of its sorting and rough sales operations to Gaborone,  the country’s capital, and to set aside a percentage of rough diamonds for local manufacturing.

		In the beginning, some firms set up minimalist operations to conform to the letter of the law, if not its spirit, but most found that with the government adopting reasonable regulations on employment, taxes and currency exchange, it was possible to turn a profit. In addition, officials from the government’s diamond office regularly visit diamond operations to check on their progress in developing high-tech diamond operations.

		The manager of one plant that employs 300 workers noted that after four years of operation, there’s still room for improvement, but it’s profitable and capable of producing very high-quality cuts and room to become more efficient.

		“Mostly we produce half-caraters and above here, because that’s where the profit is,” he said. “Sometimes, if we don’t always have suitable goods, we will work on 20- and 30-pointers to keep workers occupied, but we try not to do this too often.”

		Most of the diamond cutting operations are clustered around the new Diamond Technology Park. The largest is run by Eurostar – one of the first to open in Gaborone, in 2004 – employing 520 workers, 490 of them local, trained by Chinese technicians from the company’s facility in that country.

		The company has demonstrated its commitment to Botswana by building Africa’s largest diamond processing facility, which has room to double its capacity, said Eric Van Pul, the manager. All new workers go through six months of training; they then work side-by-side with an experienced colleague to ensure quality standards.

		Now, the facility can produce precision cuts or any shape and size with quality on a par with any of the company’s Indian facilities.

		While a number of companies are claiming success, challenges remain. There is little diamond manufacturing and technical expertise or experience “on the ground,” so foreign workers  need to come in and train people from scratch.

		And Botswana, with its relatively high costs structure – it costs an average of about $60 per carat to manufacture diamonds there, compared to $15 to $20 in India, and $25 to $25 in China – will probably not grow into a major cutting center. The diamond manufacturers doing business there believe, however, that producing for niche markets – higher quality branded diamonds, for example – is sustainable over the long term.

		They are optimistic that the government’s local rough diamond sales, operating from the Diamond Technology Park under the banner of Okavango Diamond Company, will enable them to further expand their operations.

		Okavango began selling rough this month by tender auction and will eventually offer some three million carats yearly, about 10% of its current production, in a series of monthly sales.

		The park has room for growth and manufacturers there are optimistic that they will need that extra space after the government, trading as Okavango Diamond Tenders, begins selling rough.

		“These sales,” Rutang Moses said, “could enable Botswana to become both a marketplace and polishing center for diamonds.”

	A Chinese technician works with a local trainee on the use of rough diamond planning machines. These high tech units scan the rough inside and out and the most economical way of cutting the stone.

Eurostar’s Botswana operation, employing more than 500 workers, is Africa’s largest diamond manufacturing plant. @topic:11


Publish Year: - Title: Demand Improves After Slow Autumn, But Challenges Remain Abstract: Demand for diamonds and gemstones in the United States appears to be picking up – spottily – after last fall’s doldrums. The U.S. Department of Commerce reported that jewelry sales increased by 14.7% in January compared to January 2012. Even more encouraging was the fact that jewelry prices were, on average, about 3% lower. The U.S. economy has been buoyed by a surging stock market, a growing (if slowly) employment market and reviving housing market.

In Asia, business at the recent Hong Kong Watch and Jewellery Show exceeded expectations, especially for diamond demand. Though there is slow growth in demand in China, demand for diamonds in Japan is improving and many retailers in both countries have been short on inventory.

Chow Tai Fook, Asia’s largest retailer, reported same-store sales decline of 3% by volume, 2% by revenue for the first two months of the year, noting that sales in Hong Kong and Macau were rising strongly, but those in Mainland China continued to soften.

Diamond producers from across the spectrum will welcome any improvement in the market. All told, 2012 was a challenging year: rough prices declined an average of 12% from 2011 and the diamond market was beset by high inventories, a credit squeeze and slow growth in demand from key consumer markets.

Although prices for rough and polished appear to have stabilized, the dilemma for diamond mining companies is how to manage the industry goal of reducing credit and inventories, and still improve revenues.

Several mining companies reported losses for 2012; others, including Rio Tinto, De Beers and Alrosa, are in the middle of very costly redevelopment projects. De Beers’ rough diamond sales plunged 16% last year, while its mine production also declined significantly.

BHP Billiton, which just sold its stake in Canada’s Ekati mine, reported that its diamond revenues declined 44% as Ekati’s production fell by more than one-third. Rio Tinto’s sales remained relatively flat, but underground operations at Argyle pushed the diamond division into a $43 million loss for 2012.

The leading producer of colored stones, Gemfields plc, is gearing up for a better year after reporting that its revenue fell 39 % to $27.7 million for the six months ending Dec. 31, 2012 compared to the same period in 2011. The company noted that it had conducted only one emerald auction during in that period, selling a total of 930,000 carats for $29.71 per carat. The company, which operates the Kagem Mine in Zambia, announced that it will hold more auctions this year as it gears up a new marketing program featuring film star Mila Kunis. @topic:7


Publish Year: 2013 Title: China Market: The New Frontier Abstract: China, the world’s second-largest jewelry consumer after the United States, is also the second-largest jewelry manufacturing center after India. There is enormous potential for diamond jewelry in China, where the government has supported the industry through major policy decisions: reducing the VAT (value-added tax) on diamonds, abolishing import duties, and setting up the Shanghai Diamonds Exchange for trading in rough and polished diamonds. The government has signed multibillion dollar resources-for-infrastructure deals with various African governments, securing its supply of rough diamonds. These efforts have drawn a huge flow of capital investment from diamond companies in Tel Aviv and Antwerp. Skilled diamond craftspeople have been brought in from Surat, India, to train Chinese workers.

Overall, China has cheaper labor costs than India, and its workforce provides better finishing of jewelry. Much of the work in Chinese jewelry factories is automated, and the level of technology and infrastructure is higher than in India. India produces every size and type of rough, while China mostly manufactures sawables. While India holds the advantage in manufacturing, China is a major consumer of polished diamonds. China is also better at jewelry manufacturing. But there is no original Chinese brand of international jewelry, and country needs better communication with the outside world.

Abstracted by Guy Lalous @topic:7


Publish Year: - Title: Spring 2024 G&G Available Now Abstract: To celebrate Gems & Gemology ’s 90th anniversary, our spring issue kicks off this milestone year with a variety of discoveries. With three feature articles, the latest installment of Diamond Reflections, our recap of the 2024 Tucson shows, the annual G&G Challenge quiz, and an inside look at an extraordinary platinum and garnet necklace, there’s something for everyone inside.
Mineralogy and Geochemistry of Turquoise from Tianhu East, Xinjiang, China
A team led by Ling Liu reports on turquoise from the Tianhu East deposit in northern China. The authors cover the area’s geology and the results of their studied samples, identifying a geographic origin indicator to distinguish Tianhu East turquoise from other Chinese sources.
“Ice Jade” from Guatemala
A translucent variety of jadeite jade from Guatemala has become popular in the Chinese market in recent years. Zhaoying Huang and coauthors share their study characterizing the pale green material known as “ice jade” from the Morales mine.
Nanoscale Techniques for Characterizing Gemstone Coatings: A Case Study on Synthetic Moissanite
Tsung-Jen Wu and fellow researchers study coated synthetic moissanite, using it as a basis for analyzing colored coatings on a variety of polished gemstones. The authors characterize the colored coatings and offer methods for identifying techniques used in the coating process.
Lab Notes
GIA’s global laboratory staff present their latest findings in the Lab Notes section, including a large CVD-grown diamond resubmitted after HPHT treatment, an iridescent imitation pearl resembling a pen pearl, and the first submission of a rare titanoholtite.
Micro-World
The Micro-World section, dedicated to the inner world of gemstones, features a striking cluster of trigons in diamond, pink and red epidote crystals in quartz, an exceptional iris effect in Brazilian watermelon tourmaline, and more.
Diamond Reflections
The Diamond Reflections column returns in this issue to investigate the journey of superdeep diamonds to the earth’s surface.
Gem News International
The Gem News International section starts with our coverage of the 2024 Tucson gem shows, compiling interesting finds, handcrafted designs, popular trends, and more from the shows. The GNI section continues with regular content, including a report on new beryl and emerald specimens from Newfoundland and updates on rubies from both Liberia and Mozambique.
In the Spotlight
Lastly, we spotlight an incredible collaboration from Mary van der Aa and Todd Wacks: “Garanatus: From Rough to Cut.” This AGTA Spectrum Award–winning platinum necklace features 28 of the world’s rarest garnets, totaling more than 77 carats.
Gems & Gemology Challenge
The spring issue also offers the 2024 Gems & Gemology Challenge quiz. Score 75% or better and you’ll receive a certificate of completion; earn a perfect score and your name will be listed in the Fall 2024 issue. Entries for the Challenge must be submitted online by September 1, 2024. @topic:2


Publish Year: 2024 Title: Phenomenal Emeralds from Chitral, Pakistan Abstract: Cat’s-eye emerald (11.31 ct) and star emerald (4.99 ct) from Chitral, Pakistan. Photo by Lhapsin Nillapat; courtesy of Mohammed Ayub (Pretty Little Gem Co, Ltd, Bangkok).
In November 2023, GIA researchers had the chance to study a parcel of emeralds reportedly from Chitral in Pakistan. All of the stones matched previously documented characteristics of emeralds from Chitral (C.S. Hanser et al., “Comparison of emeralds from the Chitral District, Pakistan, with other Pakistani and Afghan emeralds,” Journal of Gemmology, Vol. 38, No. 6, 2023, pp. 582–599).
Among the stones were two cabochons that showed unusual phenomena: chatoyancy and asterism (see above). Both had a refractive index of 1.57 (spot reading) and a yellowish green to green color, which identified them as emerald.
Cat’s-eye emeralds are found in a number of locations, most notably Brazil and Colombia. The effect is caused by large concentrations of fine parallel tubes. Proper orientation of these linear features during cutting can result in a sharp, centered cat’s-eye when the tubes reflect light.
Star emeralds are even rarer, with most originating from Brazil and Madagascar. The effect is usually caused by very small thin films that reflect light. The proper orientation of the cabochon dome with respect to tiny platelets can result in a six-rayed star that moves across the curved surface of the stone. In this emerald, some of the platelets that create the lower left arm are highlighted by iridescent reflective colors.
To our knowledge, these are the first phenomenal emeralds from Chitral, and they offer prime examples of lesser-known phenomenal emeralds. @topic:3


Publish Year: 2024 Title: Thirty Years Later: “The Royal Tapestry” Revisited Abstract: Emmanuel and Daniel Piat (right) examine “The Royal Tapestry” together for the first time at the Alfie Norville Gem & Mineral Museum. Photo by Robert Weldon.
Three generations of the Piat family gathered at the University of Arizona Alfie Norville Gem & Mineral Museum in Tucson on February 1 to see “The Royal Tapestry” (see Spring 2022 GNI, pp. 110–111) for the first time. The tapestry (see above) was created by French master jewelry house Cristofol Paris more than thirty years ago, with Maison Piat (Paris) procuring the gemstones and facilitating their cutting. Prior to the gathering, Daniel Piat was the only family member who had seen the completed tapestry.
The tapestry contains almost 27,000 emeralds, diamonds, rubies, and blue and yellow sapphires as well as 37.5 lbs of 18K gold. Its 122 × 71 cm (42 × 24 in.) dimensions, the same as those of an Islamic prayer rug, were specified by the royal family in the Middle East who privately commissioned it. More than 25 cutters matched the stone sizes within one-tenth of a millimeter. Cristofol Paris artisans spent more than 16,000 hours crafting the tapestry. Manufacturing a work of jewels that moved and flowed like a carpet or woven cloth required a form of prong setting, new at the time, that involved fewer “shared” prongs. Throughout the process, in a time before the advent of mobile phones and digital images, materials were shipped back and forth between Paris, Bangkok, Jaipur, and the Jura region of France.
The tapestry remained with the unnamed royal family until the early 2000s, when it was sold to a private collector. Prior to its exhibition in Tucson, it had been exhibited only in Hong Kong and London for one day each.
At the Alfie Norville Museum reception, board member Shelly Sergent touched on the origin of the tapestry concept and the process of transporting it from Zurich to Tucson. Daniel Piat shared the story of the tapestry’s creation, describing the challenges presented by the design and the immense amount of work and detailed craftsmanship it required. Eric Piat noted the difficulty of sourcing the gems in a strict range of colors. Daniel said that after more than thirty years, all of the gems are still perfectly seated in more than 106,000 prongs and 26,649 seats, calling it “an engineering feat never duplicated in the jewelry world today.” @topic:6


Publish Year: 2024 Title: Precious Opal from Pedro II, Brazil Abstract: Figure 1. Pedro II is the most important opal source in Brazil. The town is located in the northeast of the state of Piauí, and opal deposits are distributed in an area about 20 km in diameter around the township. The current opal mine is an open-pit operation. Photo courtesy of Prime Gems.
Prime Gems, Inc. (New York City) offered a small quantity of precious opal from Brazil at this year’s GJX show. As an opal source, Brazil has been underrepresented for the past four decades since a “golden age” from the 1960s to mid-1970s. The inventory of Brazilian opal from Prime Gems helped inform attendees of the fine quality available from this part of the world.
Multiple states in Brazil have opal occurrences, but the most important reserves are in the Pedro II municipality, located in the northeastern state of Piauí (figure 1). According to the local artisanal miners, the first precious opals were found near the end of the 1930s. During its peak in the 1960s and 1970s, more than 30 mining operations were active. However, by the early 1980s, over two-thirds of the mines were abandoned. Currently, opal mining in this area is still small-scale and mostly manual.

Figure 2. Opal rough from Pedro II shows that opal can occur in veins in the host sedimentary rocks (left) or as thin layers attached to intrusive dikes (right). The sedimentary rocks have a light color, while the dikes are darker. Photos by Tao Hsu (left) and Robert Weldon (right); courtesy of Prime Gems.
The opals in this region are found in both primary and alluvial deposits. In the primary deposits, opal occurs in veins in the host sandstones (figure 2, left). This occurrence is similar to Australian opal deposits in that both are of a sedimentary nature. The vendor displayed an interesting rough opal attached to a piece of intrusive igneous rock, creating a “salt and pepper” appearance (figure 2, right). According to the vendor, diabase dikes intruded into the sedimentary rocks in this area. Diabase is of basaltic composition, and its main constituent minerals are plagioclase feldspar and pyroxene, which are of lighter and darker colors, respectively. This rough piece shows that opal also develops at the contact between the dike and the host sedimentary rocks.
At the region’s alluvial deposits, miners wash and manually extract opal. This is hard work but feasible for those who cannot afford mechanical equipment. Most of the miners alternate between opal mining during the dry summer and farming in the rainy season.

Figure 3. High-quality opal from Brazil shows extremely vivid play-of-color. Some are of transparent light gray to white bodycolor such as this 132.3 ct freeform (left), while others have darker bodycolor (right). Photos by Robert Weldon; courtesy of Prime Gems.
Prime Gems offered Brazilian opal with transparent light gray to white bodycolor from Pedro II, similar in appearance to white opal from Australia (figure 3, left). The play-of-color was especially charming in less transparent pieces that showed colors of the whole spectrum, with bluish and greenish colors most commonly displayed. Red play-of-color is rarer and more sought after, with a higher price tag. Some pieces with darker bodycolor resembled Australian black opal (figure 3, right).
Finished products available at the show included loose opal as cabochons, freeform polished singles or pairs, doublets, and some mosaic pieces. The top-quality materials displayed a vibrant whole-spectrum play-of-color. Opal that was of good quality but too thin for freeform single pieces was used to make doublets, with the thin opal layer glued to a dark base. To support local communities, mine operators allow the local people to use very small pieces of opal from mine waste to create mosaics for sale. The supplemental income from the sales of the mosaics can reach as much as $30 per day.
The miners informed the author that Brazilian opals are sometimes sold as Australian in the marketplace. Brazilians are proud of the quality of their opal, and opal from Pedro II is one of the two products from the state of Piauí that bear the Geographical Indication certificate. The Brazilian government grants this GI label to products or services that are characteristic of a region. The aim is to ensure that Brazilian opal is properly represented and can generate revenue to further support mining and the local communities. @topic:13


Publish Year: 2024 Title: Tucson 2024 Overview Abstract: Figure 1. A display case showing popular colors and materials seen this year in Tucson. Photo by Jennifer Stone-Sundberg; courtesy of Arizona Color Stones & Minerals.
Overall, 2024 was a good year at the various Tucson shows. Foot traffic throughout the venues was noticeably slow at times, but less window-shopping and more serious buying of particularly higher-end items made up for the lack of bustling crowds. Most vendors interviewed reported strong sales and many returning buyers, noting that sales have continued to grow post-pandemic.
The American Gem Trade Association reported a small uptick in buyer attendance (+1%) and a 3% growth in vendors at the AGTA GemFair. In fact, they only had one empty booth in both the designer showroom and the gem hall. Vendors in both venues indicated that the show floor felt slower but that visitors were there to buy, often with shopping lists. AGTA’s added security measures that included ID checks were well received by both buyers and exhibitors.
GIA’s Show Service Laboratory reported a solid AGTA show, with ruby, emerald, and sapphire making up the majority of the intake. Both the service lab and vendors noted movement of high-end, unusual, and rare stones, a common theme every year in Tucson.

Figure 2. Vintage turquoise rough from the Sleeping Beauty mine in Arizona. Photo by Jennifer Stone-Sundberg; courtesy of Arizona Color Stones & Minerals.

Figure 3. A 30.26 ct blue cushion-cut cuprian tourmaline from Mozambique. Photo by Robert Weldon; courtesy of Evan Caplan.

Figure 4. A 5.34 ct vivid green modified cushion-cut Russian demantoid garnet displaying horsetail inclusions. Photo by Robert Weldon; courtesy of Tsarina Jewels.

Figure 5. Pink and purple “Nebula” sapphire in both freeform faceted tablet (left; 7.77 × 9.20 mm, 0.82 ct) and brilliant-cut (right; 4 mm round, 0.73 ct) styles. This material is from a mine in Madagascar that produces very small stones ranging from hot pink to violet. Photos by Kalim Korey; courtesy of Caroline C.
It was hard to miss the prevalence of green to blue stones, especially in vibrant and pastel tones. They were well represented in the 2023 AGTA Spectrum and Cutting Edge Awards, and many vendors reportedly brought these colors to Tucson in response. With blues and greens leading the way, pinks and to a lesser extent purples were also highly visible (figure 1). Among the top stones spotted throughout the shows were emerald, turquoise (figure 2), opal, aquamarine, Paraíba and cuprian tourmaline (figure 3), green garnet (figure 4), and unheated Montana sapphire. Strong showings of unheated blue Ukrainian topaz, unheated bicolor green and blue zoisite, blue zircon, pink to purple garnets, electric pink and purple sapphire (figure 5), morganite, fluorescent “dragon” Malaya garnet, rose quartz, pink tourmaline, baroque pearls, and Oregon sunstone were also noted.

Figure 6. Sapphire and spinel with a visible silky haze creating a glowing, sleepy appearance were popular throughout the shows. Left: Four emerald-cut Mahenge spinel (clockwise from top: 3.00 ct purple, 1.77 ct purple, 2.40 ct purple, and 3.71 ct hot pink). Courtesy of Bryan Lichtenstein. Right: A 4.50 ct “opalescent” unheated sapphire from Sri Lanka. Courtesy of Misfit Diamonds. Photos by Robert Weldon.
Another trend was the demand for visibly unheated stones. “Silky” sapphire and spinel with needle inclusions creating a soft, glowing appearance were extremely popular (figure 6). Also referred to as “opalescent,” “hazy,” “milky,” and “sleepy,” these stones were some of the hottest at the AGTA, Gem & Jewelry Exchange (GJX), and Pueblo shows. Dudley Blauwet Gems reported selling out of all of their opalescent milky stones by the fourth day of AGTA.

Figure 7. A 0.67 ct heart-shaped pezzottaite measuring 5.61 × 6.10 mm. The rough of this rare newer gem material was found and bought in Madagascar in December 2023. The stone was cut in New York for the Tucson show, where it sold. Photo by Kalim Corey; courtesy of Caroline C.
Other noted trends included the importance of geographic origin and traceability reporting for many buyers, the popularity of fancy shapes such as hearts and pears (figure 7), and the use of white metal in jewelry both in the AGTA Spectrum Award winners and throughout the shows.

Figure 8. Two pairs of earrings designed and crafted by Caroline Chartouni using Sleeping Beauty turquoise rough she acquired more than 10 years ago. The left pair is 18K white gold with 64.53 carats of turquoise, two cabochon moonstones, and 4.40 carats of hot pink spinel. The right pair is 18K white gold with 107.30 carats of turquoise, 4.64 carats of tsavorite garnet, and 0.19 carats of diamond. Photos by Kalim Corey; courtesy of Caroline C.

Figure 9. Vintage Navajo silver bolo tie with turquoise reportedly from the Morenci mine in southeastern Arizona, which is not currently being mined for turquoise. This highly collectible material, known for its desirable blue color and iron pyrite matrix, dates back to 1864 and was a byproduct of copper mining. Photo by Kevin Schumacher; courtesy of Aaron Palke.
Demand for American stones was evident once again, with more vendors carrying sapphire from Montana, turquoise from Nevada and Arizona, and sunstone from Oregon. In fact, one of the most often encountered materials in jewelry this year was vintage turquoise reportedly from the famed Sleeping Beauty mine in Arizona (figure 8). In the past, these various American gems were available mainly from vendors directly associated with the mining claims. The Southwestern motif, always a fixture in Tucson, was decidedly more pronounced this year, with many large silver items throughout the shows, including bangles, cuff bracelets, statement earrings, necklaces, and bolo ties adorned with turquoise (figure 9), red coral, blue topaz, and opal. This observation was validated the following week when singer Post Malone performed “America the Beautiful” before Super Bowl LVIII wearing a striking silver bolo tie complete with a large bright green turquoise stone with brown matrix. The bolo was reportedly made by Navajo artist Leonard Nez of New Mexico using a piece of Royston turquoise.
In addition to the presence of vintage jewelry this year, we also found multiple examples of repurposing antiquities into jewelry. As for new finds, we report on bright blue opal from Chile, green amber from Ethiopia, high-quality orange-flash rainbow moonstone from Madagascar, and recent sapphire production from the famed Kashmir region.
We hope you enjoy our coverage of the 2024 Tucson gem shows and find the following reports informative. @topic:11


Publish Year: 2024 Title: Green Amber from Ethiopia Abstract: Figure 1. This clean piece of tumbled green amber from Ethiopia, measuring approximately 5.5–6.0 × 2.8–3.5 cm, displays flow structures and some inclusions. Photo by Cristiano Brigida; courtesy of Rainbow King Solomon Mines.
Many consumers and gem enthusiasts are most familiar with yellow and golden amber commonly found in the Baltic Sea region and the Dominican Republic. However, the gem can also be white, orange to red, or brown. In rare cases, strong fluorescence can give amber a bluish or greenish appearance.

Figure 2. Ethiopian faceted green amber, measuring approximately 18 × 18 mm. The gem looks very lively under sunlight. Photo by Cristiano Brigida; courtesy of Rainbow King Solomon Mines.
At the Pueblo Gem & Mineral Show, Rainbow King Solomon Mines showed the authors some rare green amber said to be from the Amhara region of Ethiopia. The selection consisted mainly of large tumbled pieces with a yellowish green to greenish yellow bodycolor, visible flow structure and bubbles, moderate to heavy inclusions, and numerous brown discolorations (figure 1). A few pieces contained sizable insect inclusions as well. The exhibitor presented a limited amount of experimental faceted pieces (figure 2), but these were not for sale. The faceted pieces showed a surprisingly high luster and brilliance, as well as fiery flashes of orange and green colors. Because of the material’s dark tone, prominent brown discolorations, and relative abundance of biological inclusions—no samples were tested by the GIA laboratory—the authors believe it was natural, compared to the green autoclaved copal previously described by Abduriyim et al. (“Characterization of ‘green amber’ with infrared and nuclear magnetic resonance spectroscopy,” Fall 2009 G&G, pp. 158–177).
The discovery of Ethiopian amber deposits is relatively recent, with orange to yellow amber most commonly found. Compared to other amber sources, the occurrence of green amber in Ethiopia is more prevalent but still rare overall and limited to certain localities. The amber observed at the Pueblo show matches the characteristics of the highly bio-included green amber described in detail by Bouju and Perrichot (“A review of amber and copal occurrences in Africa and their paleontological significance,” BSGF - Earth Sciences Bulletin, Vol. 191, 2020, article no. 17). @topic:2


Publish Year: 2019 Title: Brazilian Alexandrite Update Abstract: Figure 1. This pair of Brazilian alexandrites (2.41 ct and 6.7 mm each) is photographed in daylight (left) and incandescent light (right). Photos by Kevin Schumacher, courtesy of Gil International.
Gil International’s booth at the AGTA show featured something out of the ordinary: a display case with lighting selected to reveal the color change of their Brazilian alexandrites, from blue-green in daylight to reddish purple in incandescent light. Goel “Gil” Gul built the case himself, and he said it has drawn traffic to the booth over the years. Based in New York, Gil International began exhibiting in Tucson 30 years ago; 2019 was their 19th year at the AGTA show.
Gil International specializes in natural Brazilian alexandrite (see above), which exhibits a strong color change. Alexandrite was first found in Russia’s Ural Mountains in the 1830s. It wasn’t until the discovery of Brazilian sources in the late 1980s, most notably Lavra de Hematita (also called Nova Era or Itabira), that greater quantities became available, though alexandrite is still considered rare.
Alexandrite has been in greater demand over the last 15 years, Gul said, but business has been slow the last two. In the past decade, his sales to a company that caters to cruise ships have been particularly strong. He attributes this to people “always looking for something unusual” and having more time to look at jewelry while on vacation. When Gul entered the industry, aquamarine, tourmaline, and zircon were big. Sapphire has always been very strong, he said, but ruby has come down in the last five years. The demand for stones rises and falls over the decades based on jewelry house promotion, he said, citing Tiffany & Co.’s marketing campaign after the discovery of tanzanite in 1967. He added that more people are buying brown diamonds, previously considered undesirable, because of Le Vian’s branding and heavy advertising of “chocolate diamonds.”

	Brazilian alexandrite update

Gul said that every source has different color; for example, Sri Lankan alexandrite is typically an olive green in daylight, while Brazilian stones are more blue-green. He acknowledged that only laboratory testing can definitively determine country of origin, but he can often make an educated guess based on color. He noted that alexandrites from India are sometimes reported as Brazilian, but he can tell that they are from India because the color change is not as strong and the green tends to be lighter.
Born in Afghanistan and educated in Israel and New York, Gul worked in accounting for a decade before being introduced to the gem and jewelry industry by his four older brothers. They were already selling ruby and sapphire, so they sent him to Brazil. On his first trip to Teófilo Otoni, Minas Gerais, in 1990, Gul bought emerald. He saw some alexandrite but didn’t buy any until his next visit. He later found out that the stones were from Lavra de Hematita.
“You buy one stone, but you’ve got three stones,” he said, referring to alexandrite’s color change. “I felt I could improve my life with this stone.”
Gul bought alexandrite from a broker in Teófilo Otoni for several years and contacted the miner directly about 15 years ago. The miner didn’t sell the rough; he had the stones cut in Hong Kong and Thailand, so he controlled the production entirely. Gul began to buy directly from him in Hong Kong.
Gul found that unlike many in the industry, the miner did not like to bargain. So he accepted the miner’s prices, and as Gul bought more stones, the miner gave him better deals. As Gil International became stronger in alexandrite, Gul and the miner became good friends. Gul has bought almost all of his alexandrite from him.
“The way to make a better business is to find a relationship with the miner,” Gul said. “If you have a good relationship, he can trust you; you can trust him. Sometimes even big companies with big money try to bargain, so they don’t find a relationship with the miner and can’t buy from him.”
Gul spoke of turning down the miner’s repeated offers to buy goods on memo—including an offer of $12 million of goods in 2010, when the miner closed seven stores in Greece after the 2008 market crash. “I buy what I can,” he said. “And he feels that I’m different [than other dealers] and gives me a chance to do more business.” @topic:1


Publish Year: - Title: Winter 2023 G&G Available Now Abstract: The Winter issue of Gems & Gemology is bursting with exciting new content! In addition to three feature articles, it offers a field report, a new inclusions chart, the latest installment of Colored Stones Unearthed, and as always, our regular quarterly sections.
TOPAZ FROM MASON COUNTY, TEXAS
A team led by Dr. Roy Bassoo reports on Texas topaz, covering the gem’s mining history in Mason County, followed by a study of its gemological and compositional characteristics. The authors also use machine learning and statistical modeling of trace element data from worldwide topaz sources to provide a basis for determining geographic provenance.
BOHEMIAN GARNETS AS DECORATIVE MATERIALS FOR GLASS VESSELS FROM THE LATE SIXTEENTH TO EARLY EIGHTEENTH CENTURIES
Dr. Karl Schmetzer and fellow authors research a method of setting cut garnets on glass objects, examining vessels at two museums in Germany. The article begins with the historical and legal context of the technique, invented by Claudius vom Creutz in Nuremberg circa 1591, followed by the results of their study.
A UNIQUE PETRIFIED TREE FERN FROM NORTHEAST CHINA
A petrified tree fern fossil from the Cretaceous period has drawn attention since its discovery in northeast China in 2010. Ying Yan and coauthors share their study of six samples displaying golden yellow to brown colors and distinct plant structure patterns, identifying chalcedony as the primary mineral component in the material.
SLOVAK OPAL: A NEW LIFE FOR A HISTORICAL GEM
This field report by Dr. Peter Semrád follows the resurgence of opal mining in Slovakia, which yields both precious and common varieties. Historical, geological, and mineralogical details are followed by accounts of recent mining and production based on the author’s visit to the locality and interviews with heads of the country’s two main opal producers.
MICRO-FEATURES OF BERYL CHART
Nathan Renfro, John Koivula, and coauthors add to the G&G series of micro-feature charts with this display of inclusions found in natural beryl. The wall chart, which presents 30 superb photomicrographs, is included in every printed copy of this issue, and a laminated version is available for sale in the GIA Store.

LAB NOTES
GIA’s global laboratory staff present their latest findings in the Lab Notes section, including a unique bicolor natural diamond exhibiting two distinctly different colors, a natural saltwater pearl containing a pair of foraminifera-like spheres, and a rare encounter with a large faceted orange-yellow sodalite.
MICRO-WORLD
The Micro-World section, which showcases the inner beauty of gemstones, features a stunning “sun spangle” in amber, a cross pattern visible in a natural diamond, remarkable hollandite crystals in a Brazilian amethyst, and more.
COLORED STONES UNEARTHED
Colored Stones Unearthed returns to explore the formation of sedimentary rocks, gems formed in sedimentary environments, and gems found in sedimentary environments that formed elsewhere. The column also covers the alluvial mining of these gems.
GEM NEWS INTERNATIONAL
Finally, Gem News International contributors report on a variety of topics, including a Vietnamese garnet displaying 14 trapiche patterns, an update on Virtu Gem’s ethical supply chain practices, and a summary of the fall 2023 auction season, which was marked by several surprising twists. @topic:2


Publish Year: 2023 Title: More on Virtu Gem’s Ethical Supply Chain Practices Abstract: Figure 1. These indicolite tourmalines (9.27 and 6.16 ct) from Zambia are among the variety of gems Virtu Gem offers. Photo by Robert Weldon.
We first covered Virtu Gem at the 2023 Ethical Gem Fair in Tucson (see Spring 2023 GNI, pp. 122–125). Virtu Gem gives artisanal and small-scale miners, traders, and cutters in Kenya, Malawi, and Zambia formal access to the international market and offers training in cutting, basic gemology, and mine safety.
The gems Virtu Gem sells (see figure 1) are cut in the source country and tracked with Provenance Proof Blockchain. One of Virtu Gem’s efforts is training artisans in cutting and polishing standards to meet international market expectations. Percy Maleta, Virtu Gem’s country exporter and ambassador in Malawi, said the training has attracted many cutters there and allowed them to sell gems at premium prices.

Figure 2. Gemstone cutters in Kenya, Malawi, and Zambia developed cuts to represent their countries in Virtu Gem’s National Gem Cut Course. Left to right: the Kenya Cheetah Head, Zambia Eagle, and Malawi Mbuna Fish cuts in aquamarine, amethyst, and rhodolite garnet. Photo courtesy of Virtu Gem.
In 2022, Virtu Gem launched the National Gem Cut Course in the three countries. In online workshops led by Adriano Mol from the University of Minas Gerais State, cutters learned facet development and brainstormed to design gem cuts to represent their nations. The resulting cuts (figure 2) resembled a cheetah head for Kenya, the mbuna (cichlid) fish for Malawi, and the eagle for Zambia. Buyers can order gemstones from each country in its respective cut.
Virtu Gem has received two grants from the World Bank as well as assistance from other organizations. Rio Grande donated a GemLightbox, and Virtu Gem purchased more for its three country coordinators. The GemLightboxes allow traders to upload photos and videos of gems to the online sales platform rather than export stones on consignment. In addition, Gemworld donated its World of Color books to each country coordinator, which help traders evaluate color and cut and set prices.
The donations have also been instrumental in Virtu Gem’s work with the National Gem Cutting School in Zambia, where students use the books and GemLightboxes. Virtu Gem cofounder Susan Wheeler said there are many gem cutters in Kenya, and she would like to establish a gem cutting program for women in Malawi.
Wheeler said gemology students should understand the ethical issues inherent in the traditional gemstone supply chain and the importance of cutting in the source country. She emphasized the importance of knowing that prices are based on not only the gemstones but also the labor of the miner and the jewelry manufacturer and other costs.

Figure 3. Virtu Gem’s Kenya country coordinator, Caroline Muchira, with Nadan tsavorite mine manager Daniel Chege (left) and owner John Kimuyu (right). Photo courtesy of Virtu Gem.
Virtu Gem’s country coordinator for Kenya, Caroline Muchira (figure 3), is a gem cutter by trade. While working full-time in logistics, she was inspired to travel more than 300 km by bus every weekend from Nairobi to Voi to visit the mines and talk to traders. “I was fascinated by the gemstones and how the miners could tell the difference between green garnet, green tourmaline, and pieces of green glass,” Muchira said. She planned to study gemology in retirement, but in 2009, after the company she worked for was sold, she sold all of her belongings to earn her Graduate Gemologist diploma at GIA’s Thailand school. During Muchira’s visits to Voi, she saw the issues the miners faced, especially women and youth. “Often they are unable to sell their stones at a fair price to middlemen, whose aim is to strike the lowest possible deal, leaving miners barely able to eke out a living,” she said. Virtu Gem’s system focuses on fair pricing, and Muchira now runs the organization’s pricing workshops.
Muchira’s ability to earn a GG is not the norm. Maleta said many in Malawi’s gem trade are interested in taking GIA courses but can’t afford it. “In a country with more than 60,000 artisanal and small-scale miners, Malawi probably only has two or three GIA graduates,” he said.
The communities Virtu Gem works with produce a wide variety of gemstones, but they have yet to access some resources. While some artisanal and small-scale mining (ASM) of emeralds occurs in Zambia, Wheeler pointed out, the miners are largely unable to access the more than 400 ASM emerald concessions in Zambia, in the same area as Gemfields. Two women they work with in Zambia have a digger but can’t afford the fuel to run it. “They could be producing the same quality emerald as Gemfields,” Wheeler said. “They can’t afford to do it on a regular basis, and loans are very expensive. We want to support the emerald mining. So we’re trying to work on how to go forward with sourcing and getting more supply with emeralds.”
Virtu Gem is part of the United Nations Conscious Fashion and Lifestyle Network, which highlights collaborations that further the UN’s Sustainable Development Goals (SDGs). Virtu Gem’s efforts are associated with six of the SDGs: ending poverty, ending hunger, gender equality, decent work, inclusive and sustainable industrialization, and reducing inequality. “We’re going to continue to align everything that we do in Virtu Gem with the Sustainable Development Goals so people can see that framework and what gemstones can do to make progress,” Wheeler said. @topic:11


Publish Year: 2022 Title: Quarterly Crystal: Hillocks on Beryl Abstract: Figure 1. Measuring 22.28 mm in length and weighing 31.06 ct, the outer pinacoidal surface on the termination of this Pakistani aquamarine crystal is decorated with numerous hexagonal growth hillocks. Photo by Nathan Renfro.
Whenever we study natural uncut gem minerals, we carefully examine all outer surfaces for any photogenic etch figures or growth hillocks that might yield interesting and educational photographs. For this issue’s Quarterly Crystal, we recently had the opportunity to study a very well-formed, gem-quality aquamarine crystal supplied by Ali Shad of Shad Fine Minerals in Gilgit-Baltistan, Pakistan. The aquamarine, pictured in figure 1, was reportedly from the Qandahar mine, located in the Braldu Valley, Shigar District, Gilgit-Baltistan, Pakistan.
At 31.06 ct with corresponding measurements of 22.28 × 14.50 × 11.24 mm, this aquamarine did not show etch figures on any of its crystal faces, proving that the beryl had not gone through post-growth dissolution. However, examination showed that the pinacoid was completely covered with small hexagonal growth hillocks (figure 2) of the type discussed by John Sinkankas in Emerald and Other Beryls (1981) and illustrated on page 273. The hillocks on the terminal pinacoid, which were all generally of the same small size, blanketed the termination completely. Under high magnification, the hexagonal hillocks appeared very complex in form (figure 3). Their sharp, pristine, geometric habit once again illustrated that post-growth dissolution of this crystal had not taken place.

Figure 2. The generally uniform size of the numerous growth hillocks on the terminal pinacoid of the aquamarine is clearly shown in this shadowed reflected light image. The bright colors result from light interacting with thin-film separations in the body of the aquamarine. Photomicrograph by Nathan Renfro; field of view 7.97 mm.

Figure 3. The complexity of some of the hexagonal growth hillocks on the pinacoid of the aquamarine is shown in closer detail in this differential interference contrast image. Photomicrograph by Nathan Renfro; field of view 2.32 mm. @topic:3


Publish Year: 2023 Title: Demantoid, Andradite, and Grossular from Mexico Abstract: Figure 1. Demantoid garnet (0.84 ct on the left and 0.28 ct on the right) and an orange grossular garnet (0.55 ct) from Sonora, Mexico. Photo by Diego Sanchez.
Iridescent andradite garnet is an interesting phenomenal stone that was initially produced in Nevada but has also been found in Mexico, Japan, and New Mexico. A small parcel consisting of three stones (figure 1) was recently submitted to GIA’s Carlsbad laboratory and contained some new gem material from the iridescent andradite deposit in Mexico. The deposit is located high in the Sonoran Sierra in the Mexican state of Sonora about 145 km northeast of the city of Hermosillo. The stones were provided by Marion Alberto Márquez Suárez, who works with the mine owner, Salvador Barba.

Figure 2. Mineral inclusions in a Mexican demantoid. Photomicrograph by Aaron Palke; field of view 1.26 mm.
Standard gemological testing gave a refractive index of 1.740 for the grossular garnet and over-the-limit readings for the demantoid garnets. All three samples were inert to both long-wave and short-wave ultraviolet light. Fingerprints and fields of fluid inclusions as well as colorless and dark crystal inclusions were observed (figure 2). The inclusion scenes were reminiscent of skarn-related demantoid garnet from Namibia and Madagascar rather than the horsetail inclusion scenes noted in serpentinite-related demantoid from Russia. Trace element chemistry was collected as part of an ongoing project for demantoid origin determination. Curiously, the demantoid garnets had low gallium levels ranging from 0.45 to 1.96 ppm. This is more in line with serpentine-related demantoid, with gallium less than 1 ppm, than with skarn-related demantoid, which always has gallium levels above 2 ppm. Chromium was also below detection limits, which is consistent with iron-colored demantoid from skarn-related deposits. While these Sonoran demantoid and other garnets are not currently on the market, the miners have produced up to 7 kg of the material over the last 10 years. @topic:1


Publish Year: 2023 Title: Texas Topaz, Slovak Opal, a Beryl Inclusions Chart, and More Abstract: Welcome to the Winter 2023 edition of Gems & Gemology ! This issue brings an exciting conclusion to the volume year with three feature articles, a field report, a colorful new inclusions chart, and the return of the Colored Stones Unearthed column along with our other regular columns.
“…a prized gemstone from the United States: Texas topaz, sought after for its domestic provenance and rare natural blue color.”
Our first article explores a prized gemstone from the United States: Texas topaz, sought after for its domestic provenance and rare natural blue color. Dr. Roy Bassoo and coauthors begin with a historical account of topaz from Mason County, Texas, followed by discussion of its geologic origin, compositional characteristics, manufacture, and significance to the gem trade. In addition, the authors seek to provide a basis for determining geographic provenance.
Next, Dr. Karl Schmetzer and fellow researchers investigate a technique for setting cut garnets on glass objects, invented by Claudius vom Creutz of Nuremberg in the late sixteenth century. Examining two glass vessels at museums in Germany, the authors analyze the stones decorating the objects and the methods used to attach them.
Petrified tree fern from northeast China is the topic of our next article. A team led by Ying Yan reports on the gemological properties, chemical composition, and appearance of this material, which displays a beautiful pattern and is being used in intricate carvings in China.
Our fourth article, a field report from Dr. Peter Semrád, presents the revival of Slovak opal mining. It provides a brief history of mining in the area and details on geology and mineralogy, followed by coverage of recent mining activity, production, and marketing.
To close out our features, GIA researchers led by Nathan Renfro and John I. Koivula offer a captivating look at the internal features of beryl, with a foldout chart featuring 30 remarkable photomicrographs. Laminated versions of the chart, along with the six other inclusion charts in the series—emerald, sapphire, ruby, diamond, opal, and spinel—are available at store.gia.edu.
G&G’s regular columns continue to provide the latest gemological findings. Noteworthy updates from GIA laboratories are summarized in Lab Notes, including an HPHT-treated laboratory-grown diamond featuring dramatic color zoning, an antique Indian-style headdress decorated with seed pearls, and a rare faceted thomsonite. Micro-World showcases the inner landscapes of gemstones with striking hollandite crystals in a Brazilian amethyst, a stress halo resembling a butterfly in a natural diamond, a metal sulfide crystal suspended in a padparadscha sapphire, and more. Colored Stones Unearthed returns in this issue, covering the formation and mining of gemstones from sedimentary rocks. Finally, highlights from the Gem News International section include reports on pyritized triceratops fossils from South Dakota, training for artisanal diamond miners in Liberia, and a recent discovery of blue amblygonite-montebrasite from Rwanda.
We hope you enjoy the latest edition of Gems & Gemology ! @topic:2


Publish Year: - Title: Fall 2023 G&G Available Now Abstract: The Fall issue of Gems & Gemology has a wide range of colored stone topics in store, from the cause of color in yellow sapphire to the characterization of Oregon sunstone, Ukrainian beryl, and British Columbian iolite. In addition to the four feature articles and our quarterly sections, we see the return of Diamond Reflections and the 2023 G&G Challenge results.
YELLOW SAPPHIRE: NATURAL, HEAT-TREATED, BERYLLIUM-DIFFUSED, AND SYNTHETIC
Dr. John Emmett and fellow researchers share their in-depth study of the various chromophores responsible for color in natural, heat-treated, beryllium-diffused, and synthetic yellow sapphire. Their results reveal that Fe3+, a trapped hole associated with iron (h•-Fe3+), or a combination of the two are involved in the coloration of natural and treated yellow sapphire, while color in synthetic yellow sapphire is attributed to the Ni3+ chromophore or a combination of Ni3+ and Cr3+.
SPECIAL COLORS AND OPTICAL EFFECTS OF OREGON SUNSTONE: ABSORPTION, SCATTERING, PLEOCHROISM, AND COLOR ZONING
Dr. Shiyun Jin and colleagues investigate the special colors and optical effects caused by metallic copper inclusions in Oregon sunstone using samples from various mines. Their study covers the absorption and scattering of light as well as pleochroism and color zoning in this increasingly popular gemstone from the United States.
ETCH PITS IN HELIODOR AND GREEN BERYL FROM THE VOLYN PEGMATITES, NORTHWEST UKRAINE: A DIAGNOSTIC FEATURE
The Volyn pegmatite field in Ukraine is known for the production of green beryl and the yellow beryl variety heliodor. Led by Dr. Gerhard Franz, researchers present their study examining the dissolution features of Ukrainian heliodor and green beryl and offer criteria to distinguish them from samples found in other localities.
IOLITE FROM THE THOR-ODIN DOME, BRITISH COLUMBIA, CANADA: GEOLOGY, CHEMICAL COMPOSITION, INCLUSIONS, AND CAUSE OF CHATOYANCY
Dr. Philippe Belley reports on gem-quality cordierite from two recently discovered occurrences in British Columbia—Blue Arrow and Blue Bear. The paper details the geological setting and gemological properties of this violet-blue iolite and notes the potential for future discoveries in the area.
LAB NOTES
GIA’s global laboratory staff share their latest findings in the Lab Notes section, including two traditional Indian pearl submissions to the Mumbai lab—a Bombay pearl bunch and two pearl nose rings—and a ruby filled with zinc glass examined in the Carlsbad lab.
MICRO-WORLD
The Micro-World section continues to highlight fascinating gem inclusions with an intricate moiré pattern in purple spinel, blade-like magnetite inclusions in peridot, brown matrix in an Armenian turquoise sphere mimicking planet Earth, and more.
DIAMOND REFLECTIONS
Diamond Reflections returns to explore diamonds formed within eclogitic mantle host rocks and what they reveal about Earth’s dynamic processes.
GEM NEWS INTERNATIONAL
Finally, GNI contributors report on new occurrences of basalt-related gems in southeast Vietnam, an assessment of responsible pearl farming in Australia, the opening of the Gübelin Gem Museum in Switzerland, and more. @topic:2


Publish Year: 2023 Title: Cause of Color in Yellow Sapphire, Plus Characterization of Oregon Sunstone, Ukrainian Beryl, and British Columbian Iolite Abstract: Welcome to the Fall 2023 issue of Gems & Gemology ! This issue delivers four feature articles covering a range of colored stone topics, from a color study of yellow sapphire to a new source of violet-blue iolite in Canada.
“…investigate the various chromophores responsible for color in four types of yellow sapphire—natural, heat-treated, beryllium-diffused, and synthetic.”
In our lead article, Dr. John Emmett and coauthors investigate the various chromophores responsible for color in four types of yellow sapphire—natural, heat-treated, beryllium-diffused, and synthetic. These chromophores include Fe3+, a trapped hole associated with iron (h•-Fe3+), and a combination of the two, all of which are involved in the coloration of natural and treated yellow sapphire. Synthetic yellow sapphire, on the other hand, is usually colored by the Ni3+ chromophore or by a combination of Ni3+ and Cr3+.
Next, Dr. Shiyun Jin and colleagues share their research on the special colors and optical effects caused by metallic copper inclusions in Oregon sunstone. Using samples from different mines in Oregon, they explore absorption and scattering, pleochroism, and color zoning in this gem-quality feldspar known for its wide range of beautiful colors.
A team led by Dr. Gerhard Franz reports on the morphological characteristics of green beryl and the yellow beryl variety heliodor from the Volyn pegmatite field in Ukraine. The authors observe an abundance of characteristic etch pits throughout the samples and offer details on distinguishing Volyn green beryl and heliodor from those found in other localities.
Dr. Philippe Belley contributes our final feature article, an examination of violet-blue iolite from new deposits in the Thor-Odin dome in British Columbia, Canada. Various samples are analyzed to reveal the nature of their chemical composition, mineral and fluid inclusions, and chatoyancy. The abundance of cordierite-rich rocks in the Thor-Odin dome indicates potential for future iolite discoveries in the area.
G&G’s regular columns contain exciting gemological findings from all over the world. Lab Notes details recent noteworthy submissions to GIA’s laboratories, including a 4.04 ct ring fashioned from a single-crystal CVD-grown diamond, a nacreous atypical bead cultured pearl featuring a flame-like surface structure, and a heart-shaped ruby filled with zinc glass. Observations of fascinating internal features are captured in the Micro-World section, including a rare iridescent ferropericlase in brown diamond, bladed columbite crystals in topaz, and zigzag-patterned fingerprints in blue sapphire. Diamond Reflections returns in this issue, focusing on diamonds formed within eclogitic mantle host rocks. Finally, Gem News International offers brief studies of Burmese chameleon amber, Guatemalan omphacite jade, and other gem materials, as well as coverage of the recent Turquoise United conference and the Chicago Responsible Jewelry Conference.
Congratulations to this year’s G&G Challenge participants who received a perfect score! See a list of the top scorers on page 322. Thank you to those who put their knowledge to the test.
We hope you enjoy the latest edition of Gems & Gemology ! @topic:3


Publish Year: 2023 Title: Nickel-Diffused Spinel, Vietnamese Augite, Brown Mammoth Ivory, and More… Abstract: Welcome to the Summer 2023 issue of Gems & Gemology! Loaded with noteworthy content, the articles in this volume cover timely topics, such as a new treatment process identified in natural spinel, a recent source of augite in Vietnam, and research identifying the origin of the surface color of brown mammoth ivory.
“…an undisclosed diffusion treatment process for spinel that is being used to convert lightly colored gems to hues ranging from green to blue.”
In our lead article, Dr. Michael Jollands and fellow GIA researchers report on an undisclosed diffusion treatment process for spinel that is being used to convert lightly colored gems to hues ranging from green to blue. Testing a set of spinel samples represented as “cobalt diffused” revealed that the stones were actually diffused with nickel. With this treatment now present in the gem market, the authors suggest identification criteria for spinel samples within the green to blue color range.
Next, a team led by Le Ngoc Nang investigates a variety of gem-quality augite from Dong Nai, Vietnam. The magnesium-rich augite, characterized by its intense dark orangy brown or dark green color under transmitted light, has potential use in jewelry and as a carving material.
Another carving material, mammoth ivory, is typically found with a brown surface color. Our third article, from Zhaoying Huang and coauthors, examines the origin of this color. They determine that iron oxides and sulfides and manganese oxides and hydroxides crystallized on the mammoth ivory’s surface while underground, causing it to turn brown.
Our regular columns offer a host of interesting finds from all over the globe, including an aquamarine displaying asterism, a CVD-grown diamond over 34 carats, and an exceptionally large South Sea cultured pearl in the Lab Notes section. Explore the inner wonders of gemstones in Micro-World, with a feather inclusion resembling a mountain range in natural diamond, metallic platelets in Brazilian Paraíba tourmaline, an intriguing metal sulfide crystal in garnet, and more. Colored Stones Unearthed returns in this issue, covering gemstones that formed through metamorphic processes. Highlights from the Gem News International section include the characteristics of treated rubies from Greenland as they become more common in the market, the 2023 Sinkankas Symposium, and the latest auction season. Also in this issue, we put fire obsidian In the Spotlight. Tom Dodge’s impressive lapidary work reveals the vivid spectrum of iridescent colors in this rare volcanic glass found only in the Glass Buttes region of Oregon.
Lastly, we invite you to join the G&G Facebook group (facebook.com/groups/giagemsgemology). Since its launch in February 2020, our growing community has surpassed 35,000 members. Thank you for your continued support and interest in Gems & Gemology! @topic:2


Publish Year: 2023 Title: 2023 Sinkankas Symposium Abstract: Brendan Laurs, Meg Berry, and Aaron Celestian at the Sinkankas Symposium. Photos by Judy Colbert.
The Nineteenth Annual Sinkankas Symposium was held at GIA in Carlsbad, California, on April 22. Cohosted by GIA and the Geo-Literary Society, the event’s theme was “San Diego County Gems and Minerals.” Pink tourmaline, kunzite, spessartine garnet, and aquamarine were the focus of 11 presentations (see above).
Emcee Robert Weldon (GIA, Carlsbad) welcomed the capacity crowd to the first in-person Sinkankas Symposium since 2019. Dr. Raquel Alonso-Perez (Mineralogical and Geological Museum, Harvard University) recounted the history of the Pala Chief mine starting in the nineteenth century. Bill Larson and son Will Larson (Pala International, Fallbrook, California) examined the tourmalines of the Pala Gem Mining District and the Himalaya mine, respectively. Brendan Laurs (Journal of Gemmology) overviewed the geology of San Diego County pegmatites. Nathan Renfro (GIA, Carlsbad) showed fascinating inclusion features of various gem minerals from the county. Dr. Skip Simmons (Maine Mineral and Gem Museum, Bethel, Maine) detailed the tourmaline mineral group’s compositional variation, crystal structure, and classification.
Cal Graeber (Fallbrook, California) shared insights based on more than 50 years of experience mining and collecting San Diego County minerals. Lapidary artist Meg Berry (Megagem, Fallbrook, California) shared her decades of experience cutting locally mined tourmalines and showed several of her award-winning creations. By video, Paula Crevoshay (Albuquerque, New Mexico) looked back on her love affair with the gems of Southern California, which have often been incorporated into her acclaimed jewelry designs. Dr. Aaron Celestian (Natural History Museum of Los Angeles County) spoke on the use of gems to illuminate art and science. Using the museum’s special exhibit of Crevoshay jewelry as an example, he explained its integration with social media and traditional print media to communicate scientific content. Dr. George Rossman (California Institute of Technology, Pasadena) joined Dr. Aaron Palke (GIA, Carlsbad) in examining the range of colors and color-causing elements in San Diego County gem minerals.
The next Sinkankas Symposium, scheduled for May 2024 in Carlsbad, will be on Burmese gems from Mogok. @topic:2


Publish Year: 2023 Title: Susan Jacques Receives Robert M. Shipley Award Abstract: Susan Jacques accepts the Robert M. Shipley Award at the American Gem Society’s 2023 Conclave in Louisville, Kentucky. Courtesy of AGS.
Susan Jacques, GIA’s president and CEO, has received the American Gem Society’s Robert M. Shipley Award, honoring her steadfast commitment to the jewelry industry. Named for the founder of GIA and AGS, the prestigious award was presented to Jacques at the AGS Conclave in Louisville, Kentucky, on May 2, 2023 (see above).
Jacques previously served as president and CEO of Borsheims in Omaha, Nebraska, one of the nation’s largest independent jewelry stores, where she reported directly to Warren Buffett. She served on GIA’s Board of Governors beginning in 1996 and held the chair position from 2008 to 2013 before her appointment as president and CEO in 2014. Jacques holds a Graduate Gemologist diploma from GIA and is a fellow of the Gemmological Association of Great Britain. She is the sixth recipient from GIA to win the award. @topic:6


Publish Year: 2023 Title: Pink Zektzerite Abstract: An exceptional pink zektzerite, cut as a square modified step cut, measuring 8.08 × 7.39 × 6.89 mm and weighing 2.95 ct. Photo by Diego Sanchez.
Zektzerite, a member of the tuhualite group, is a very rare collectible mineral currently mined from only two sources: Okanogan County in the U.S. state of Washington (Spring 2011 Gem News International, p. 61), and the Darai-Pioz Valley in Tajikistan (L.A. Pautovet et al., “Zektzerite—occurrence in Tadzhikistan,” Mineralogicheskii Zhurnal, Vol. 14, pp.  75–78). With the chemical formula NaLiZrSi6O15, these rare crystals are found in miarolitic cavities in riebeckite granite, along with many other rare minerals. The zektzerite crystals found in these locations are primarily between 4 mm and 15 mm and usually yield small faceted gems weighing less than 2 ct. This material is typically found with a low transparency and muted color saturations. Perfect cleavage in two directions and a brittle tendency make this fragile stone very difficult and risky to cut. Due to its low durability and overall dull appearance, collectors tend to leave zektzerite in its natural rough state.
An outstanding example of faceted gem-quality zektzerite (see above) was recently submitted to GIA’s Carlsbad laboratory. The stone weighed 2.95 ct, measured 8.08 × 7.39 × 6.89 mm, and had a refractive index ranging between 1.578 and 1.584. A specific gravity of 2.81, along with Raman and infrared spectroscopic testing, all matched zektzerite, with no indication of dye or polymers. The outstanding pink color, relatively high clarity, and impressive size of this stone sets this specimen far above any other faceted zektzerite previously reported. @topic:1


Publish Year: 2013 Title: Rock Buttons from the United States Abstract: Figure 1. These rock buttons were seen in Tucson. Bottom row, left to right: blue veil quartz from Washington, rhodonite from Colorado, amazonite from Virginia, serpentine from California, black jasper from Oregon, copper-infused brick from Michigan, jasper from Idaho, oligoclase from Nevada, fossilized coral from Alaska, polka-dot agate from Oregon, and lemon chrysoprase from Australia. Top row: glacier stone from Idaho, bertrandite from Utah, and black jasper from Oregon. Courtesy of Columbia Gem House. Photo by Eric Welch.

              At the AGTA show, Columbia Gem House (Vancouver, Washington) introduced its American rock button collection. The rocks were collected from about 25 different states, then processed and finished in the company’s own cutting facilities. The rocks are sliced and shaped into round buttons and drilled through along different directions. Each button is about 3–4 mm thick and 1–3 cm in diameter. Some are polished, while others have a dull finish. Natural gemstones are mounted in some of the rock buttons, bringing out the colors of both.

The collection features a wide variety of rocks (figure 1). Blue veil quartz, a combination of quartz matrix with blue azurite veins, was discovered in Washington state. Perhaps the most interesting item is copper-bearing brick from a Michigan copper smelter. For years, melted copper dropped on the floor and sealed the fractures in the bricks, giving them a unique look after polishing. Green serpentine, the California state rock, is a metamorphic rock composed of magnesium-rich silicate minerals. Amazonite from Virginia is the beautiful bluish green variety of microcline. With some minor albite stripes, it displays an alternating blue and white pattern. From Utah comes bertrandite, a beryllium source composed of many different minerals. Bertrandite is just one mineral component of the rock, which is quite rare; most are destroyed in ore crushers before they can reach the jewelry market. Other interesting specimens included rhodonite from Colorado, black jasper and polkadot agate from Oregon, oligoclase from Nevada, coral from Alaska, and glacier stone from Idaho.

These rock buttons are sold individually. Designers or consumers can use them in any combination to create their own custom looks. The buttons can be strung on metal, leather, or other materials to form individualized necklaces and bracelets. @topic:2


Publish Year: 2013 Title: Dumortierite-Quartz Rock Presented as Sapphire Abstract: Figure 1. These 5.16 and 2.59 ct specimens, submitted as sapphire and initially thought to be dyed quartzite, were identified as dumortierite-quartz rock. Photo by G. Choudhary.

              The Gem Testing Laboratory of Jaipur, India, received for identification an opaque blue specimen, submitted as sapphire. The 5.16 ct cabochon (figure 1, above) measured 12.59 × 10.28 × 4.71 mm. Examined under a fiber-optic light source, the specimen displayed an uneven blue coloration associated with dyed materials, possibly dyed quartzite.

Gemological testing gave a vague spot RI around 1.55 and a hydrostatic SG of 2.99.The stone fluoresced strong blue to short-wave UV and was inert to long-wave UV. It showed no reaction when viewed with the Chelsea color filter and no distinct absorptions using the desk-model spectroscope, reactions that would preclude the possibility of dyeing. The RI was consistent with quartz, but the SG value ruled out that possibility. Because of the curved surface and opacity of the cabochon, we asked the client to provide a specimen with a flat polish, enabling us to properly study the material. The client also provided a thin slice of the material (figure 15, right), which allowed light to pass through easily. The properties of the slice were similar to those recorded for the cabochon. Two RI readings were obtained while slightly shifting the slice, however. Although the readings were not clear, shadow edges were seen at about 1.54 and 1.68.

Initial microscopic observations of the slice with strong transmitted light suggested blue color concentrations along the boundaries of white to colorless grains, as seen in dyed materials (figure 2, below). Yet the interstitial areas were wider than those of dyed quartzite or any other dyed substance. On further examination of the slice, inhomogeneous blue and white granular texture became evident, where some blue grains were also visible. Reflected light revealed a clear difference between the blue and whitish portions (figure 16, right). The sharp-edged whitish irregular grains, which appear gray in the image, seemed to be embedded in the blue matrix. Also, the white portion had a much duller luster than the blue one. These features suggested that the blue color was indeed natural and that the uneven coloration was not the result of dyeing, but rather a mixture of white and blue materials.

	Figure 2. Uneven blue and colorless areas (left) suggested color concentrations associated with a dyed specimen, but reflected light (right) revealed a clear difference between the blue and whitish portions. The sharp-edged whitish irregular grains (which appear gray in the image) seemed to be embedded in the blue matrix. The white mineral was identified as quartz and the blue mineral as dumortierite. Also note the difference in the luster of two areas, although both minerals have similar hardness. Photomicrographs by G. Choudhary; magnified 32×.
UV-Vis-NIR spectroscopy of the slice in the 200–2000 nm region showed broad absorption bands (figure 3) centered at ~290 and ~610 nm, which are assigned to the Fe2+-Ti4+ charge transfer (see Platonov et al., “Fe2+-Ti4+ charge-transfer in dumortierite,” European Journal of Mineralogy, Vol. 12, No. 3, pp. 521–528). This was confirmed by EDXRF analysis, which detected the presence of Fe and Ti along with Al, Si, Ca, and As. In the DiamondView, the blue portions gave strong blue reactions while the white grains remained inert (figure 4).

	Figure 3. The slice’s UV-Vis-NIR spectrum in the 200–2000 nm region showed broad absorption bands centered at ~290 and ~610 nm, which are assigned to Fe2+-Ti4+ charge transfer and associated with dumortierite.
Raman analysis using a 532 nm laser confirmed the blue and white minerals as dumortierite and quartz, respectively. The blue durmortierite revealed major peaks in the 200–2000 cm–1 region at ~206, 290, 396, 446, 506, 844, 945, and 1068 cm–1, while the white quartz showed major peaks at ~206, 263, 353, 464, 807, 1080, and 1157 cm–1.

These peaks are consistent with those reported for dumortierite and quartz in the RRUFF database. Furthermore, the SG value of 2.99 suggested a composition of approximately 54.64% quartz and 45.36% dumortierite (assuming an SG of 2.65 for pure quartz and 3.40 for dumortierite, while disregarding other accessory minerals).

	Figure 4. DiamondView imaging revealed strong blue fluorescence in the dumortierite portion of the slice, while the quartz grains appeared dark and remained inert.
Identification of this specimen would have been difficult in the absence of Raman analysis, though UV reactions and a vague RI shadow edge offered some clues. For several years dumortierite has been known to occur with quartz as rock and massive forms, but it is not routinely seen in the trade, perhaps due to lack of awareness or because it is being misrepresented, as in this case. The client had no information on the origin of these specimens, which were purchased on the local market, but dumortierite in quartz has been reported from India (R. Webster, Gems, 5th ed., revised by P. G. Read, Butterworth-Heinemann, Oxford, UK, 1994). @topic:1