Title: Large Synthetic Moissanite with Silicon Carbide Polytypes Abstract: Figure 1. This 29.73 ct synthetic moissanite (left) was submitted as a black diamond. Surface-breaking graphite inclusions were easily observed, including the largest one at the upper left table edge. The mosaic patterns on the table surface became distinct when viewed under a Raman microscope (right). Photos by Sood Oil (Judy) Chia, left, and Kyaw Soe Moe, right.

Silicon carbide (SiC) is composed of a carbon atom surrounded by four silicon atoms in a tetrahedral form. Colorless synthetic moissanite is pure silicon carbide; the incorporation of impurities produces colors, including black. Its high hardness (second only to diamond) and thermal conductivity make it a convincing diamond simulant. Both transparent and opaque synthetic moissanites have been submitted to GIA’s laboratory over the past two decades. In this report, we examine a 29.73 ct synthetic moissanite submitted as a black diamond (figure 1, left).
An uneven surface and surface-breaking black inclusions were visible with the unaided eye. Mosaic patterns of light and dark gray regions were observed under a microscope and became distinct in the Raman image (figure 1, right). Small cavities and polish lines in different directions were present on the table surface, and a granular texture was observed in a large cavity on the girdle. Raman spectroscopy identified the dark gray regions as silicon carbide.

Interestingly, each random testing spot showed mixed bands of silicon carbide polytypes (i.e., identical chemical composition but a slightly different crystal structure). The polytype 6H-SiC (6 = the number of stacking sequences, H = hexagonal, and SiC = silicon carbide) was detected by Raman bands at 789.6, 765.0, and 148.0 cm–1. Other polytypes were also distinguished by Raman bands: 3C-SiC (C = cubic) at 970.1, 968.4, 797.8, 795.4, and 788.2, cm–1; 4H-SiC at 785.7 cm–1; and 15R-SiC (R = rhombohedral) at 768.4 cm–1 (figure 2; see also P. Colomban, “SiC, from amorphous to nanosized materials, the example of SiC fibers issued of polymer precursors,” in M. Mukherjee, Ed., Silicon Carbide—Materials, Processing and Applications in Electronic Devices, InTech, 2011, pp. 161–186). In addition to these bands, a sharp Raman band assigned to silicon was detected at 520.2 cm–1 at a few spots. Bands corresponding to 6H-SiC at 238.8 and 148.0 cm–1 could not be detected at all measurement locations. Light gray regions were identified as silicon at 520.0 cm–1 (figure 2, left inset). Black inclusions, both eye-visible and microscopic, were confirmed as graphite. As figure 3 illustrates, the micro-image of a graphite inclusion showed an amorphous graphite vein (broad Raman bands at approximately 1561.0 and 1339.0 cm–1) inside a crystalline graphite matrix (sharp bands at 1580.0 and 1350.0 cm–1)

Figure 2. Each random spot showed mixed Raman bands of silicon carbide polytypes: 6H-SiC at 789.6, 765.0, and 148.0 cm–1; 3C-SiC at 970.1, 968.4, 797.8, 795.4, and 788.2 cm–1; 4H-SiC at 785.7 cm–1; and 15R-SiC at 768.4 cm–1. Silicon was also found at 520.2 cm–1 in spots 2 and 3. Bands at 238.8 cm–1 (possibly related to 6H-SiC) and 148.0 cm–1 (6H-SiC) were missing at spot 3. Light gray regions with a band at 520.0 cm–1 (left inset) were identified as silicon; the black regions were identified as graphite. The spectra have been shifted vertically for clarity. Photo by Kyaw Soe Moe (right inset).

Figure 3. Micro-imaging of a graphite inclusion (inset) showed a vein in matrix. The matrix was composed of crystalline graphite, as suggested by sharp Raman bands at 1580.0 and 1350.0 cm–1. The vein was identified as amorphous graphite by broad bands at approximately 1561.0 and 1336.0 cm–1.  Photo by Kyaw Soe Moe (inset).
During SiC growth, rotation along the covalent bond generated alternate stacking layers of Si and C atoms along the c-axis with different structural sequence, which is noticeable in the (1120) plane but not along the basal plane. This rotation can occur at very low energy. Since constant growth energy is difficult to control, two or more silicon carbide polytypes can form simultaneously during the growth process; this phenomenon is called polytypism. Raman spectroscopy has been used to detect these polytypes. Although there are more than 250 known polytypes, SiC can be classified as either beta (β) or alpha (α) type. The beta type crystallizes in cubic lattice symmetry (e.g., 3C-SiC), the alpha type in hexagonal symmetry (e.g., 6H-SiC).
Traditional growth methods for silicon carbide involve sintering and hot pressing, and there are also newer techniques. Reaction-bonded silicon carbide can form when liquid silicon reacts with porous graphite. This silicon carbide contains both pure silicon (as a bonding component), and graphite. Earlier studies have suggested that black synthetic moissanite containing silicon inclusions could be grown by the physical vapor transport (PVT) method (see Winter 2009 GNI, p. 308; Spring 2011 Lab Notes, pp. 54–55). Using PVT, researchers have grown large silicon carbide bulk crystals up to 50 × 25 mm at a rate of 1.2 mm per hour at 10 kPa pressure (Q.-S. Chen et al., “Growth of silicon carbide bulk crystals by physical vapor transport method and modeling efforts in the process optimization,” Journal of Crystal Growth, Vol. 292, 2006, pp. 197–200). Nevertheless, Raman analysis at several testing points confirmed only the 6H-SiC polytype.
This sample was submitted for a Colored Diamond Identification and Origin Report, but one should always pay close attention to surface features, such as the mosaic pattern of light and dark gray regions in reflected light, together with surface-breaking black inclusions not observable in black diamond. Source: GIA @topic:4


Title: Rockefeller and Fancy Blues Highlight Spring 2018 Auctions Abstract: This 8.01 ct Fancy Vivid blue diamond pendant, mounted by Moussaieff of London, drew a top bid of over $20.4 million at Christie’s May 29 Hong Kong auction. Photo courtesy of Christie’s.

The Spring 2018 auction season recovered from a slow start to post solid – if not record-breaking – prices for top fancy colored diamonds and gemstones. The biggest auction event of the season, however, was the series of sales from the estate of Peggy and David Rockefeller that brought in more than $835.7 million, most of it destined for charitable donations.

The proceeds from the jewelry portion of the estate, auctioned in conjunction with Christie’s June 12 Magnificent Jewels sale, totaled $3.12 million against a pre-sale estimate of $780,000. The top lot of the 19 pieces from the Rockefeller collection was a 5 carat (ct) Kashmir sapphire set by jeweler Raymond Yard, which sold for $372,000, and a suite of peridot and diamond jewelry that brought $348,500.

Christies’ auctioned the Rockefellers’ collection of artwork by Renoir, Rivera, Matisse, Picasso, Monet, O’Keefe and others, along with decorative arts objects over a period of 10 days in May, realizing $832.6 million for a dozen charities.

Fancy blue diamonds were the best performers in the regularly scheduled auctions. Before the season began, dealers at the March Baselworld show had numerous calls from clients who believed fancy blues were underpriced, especially in comparison to fancy pinks. After this season, that is probably no longer the case.

On May 29 Christie’s sold a GIA-graded 8.01 ct Fancy Vivid Blue diamond for nearly $20.5 million, or $2.55 million per carat. This was not a record, but an extremely strong price.

A GIA-graded 3.09 ct Fancy Intense blue diamond drew a $5.375 million bid at Christie’s April New York auction, a record for the highest per-carat price ($1.7 million) ever paid at auction for a diamond of that grade. The following day that record was shattered by a 3.37 ct cut-corner rectangular shape diamond of the same grade that sold for $6.663 million or $1.9 million per-carat. This diamond was also graded by GIA.

The high per-carat price was unusual because the diamonds were much smaller (well under 10 carats) than previous record-setting stones.

A 95.45 ct pink Ceylonese sapphire and diamond pendant sold for $2.3 million at Sotheby’s May 15 auction in Geneva. Photo courtesy of Sotheby’s.
Provenance, not size, was the defining characteristic of the most significant blue diamond of the season. The 6.16 ct Farnese Blue sold for $6.7 million at Sotheby’s Geneva May 16 auction, nearly doubling its pre-sale estimate. The diamond, graded Fancy Dark gray-blue by GIA, was from India’s famed Golconda Mine and was first given to Elisabeth Farnese, daughter of the Duke of Parma, in 1715 when she married Philippe V of Spain. The diamond was passed down through seven generations and, as Elisabeth and Phillippe’s descendants married into other European families, it traveled from Spain to France, Italy and Austria before going up for sale this year.

Fancy pink diamonds however, struggled this season, especially at the outset. At the same Sotheby’s New York sale, a 7 ct square cut Fancy Intense pink diamond, estimated at $4.2 to $5.2 million, failed to find a buyer, as did a 7.37 ct Fancy Intense orangey pink emerald cut diamond.

The 4.59 ct ruby, set by Tiffany & Co., which had come from the estate of the famed songwriter Irving Berlin, doubled its pre-sale estimate to sell for $1.15 million at Christie’s June 12 New York auction. Photo courtesy of Christie’s.
Two major rubies achieved strong prices. A 24.70 ct Burmese ruby sold for $11 million at Sotheby’s Hong Kong, while one of the most publicized lots from Christie’s June 12 New York sale was the 4.59 ct Berlin Ruby, a Burmese stone set by Tiffany and owned by the wife of the famed songwriter Irving Berlin. The gem doubled its pre-sale estimate to sell for $1.15 million. Additionally, a 95.45 ct pink Ceylonese sapphire sold at Sotheby’s May 15 auction for $2.3 million.

The first appearance of Paraíba tourmaline in an auction top 10 occurred when a private buyer paid $2.78 million at Christie’s May 29 Hong Kong auction for a pair of 7.46 ct and 6.81 ct stones respectively, to total $194,730 per carat. That was a world auction price for this gemstone.

Paraíba tourmalines rarely appear in the top 10 auction results, but this pair, weighing 7.46 cts and 6.81 cts, sold for nearly $2.8 million at Christie’s May 29 Hong Kong auction. The $194,730 per carat price was a record for Paraíba tourmaline. Photo courtesy of Christie’s.
Other significant colorless diamonds sold, all graded by GIA, included:

a 51.72 ct GIA-graded F If diamond that sold for $9.26 million at Sotheby’s May 15 auction
a 20.47 ct D Fl old mine cut diamond sold for $2.6 million, just over its low estimate, at Christie’s June 12 sale
a potentially D If 15.36 ct heart shape diamond went for $1.57 million at Christies’ New York June 12 sale

This 51.72 ct D If diamond sold for $9.26 million at Sotheby’s May 15 auction. Photo courtesy of Sotheby’s.
Despite the season’s slow beginning, Christies’ Chairman for Europe and Asia Francois Curiel noted that the “rare and beautiful continued to hold ground.” He added that the absence of large fancy colored diamonds at auction this season was a sign of their rarity, not so much as a weakness in demand.

In addition to its regularly scheduled sales, Sotheby’s has begun a series of online auctions of loose diamonds in more commercial sizes. The auction house featured five diamonds of 1, 2, 3, 4 and 5 carats (3 round, one pear shape and one emerald cut) over a two-week period starting June 14. It will hold another auction of loose diamonds in December.

An 18th century colorless diamond and natural pearl pendant that belonged to Marie Antoinette of France, estimated to sell for $1 to $2 million, will be auctioned by Sotheby’s Nov. 12 in Geneva. Photo courtesy of Sotheby’s.
Jewels from one of history’s most legendary royals, Marie-Antoinette, will be a highlight of the fall season. Sotheby’s will be selling her jewels, which include a large diamond necklace, a natural pearl necklace and a diamond and pearl pendant, as part of the Royal Jewels of the Bourbon Parma Family sale on Nov. 12 in Geneva. Source: GIA @topic:8


Title: Screening of Mounted Melee Using the GIA iD100 Abstract: Figure 1. A diamond ring with 100 melee side stones incorporated into the setting. Photo by Sood Oil (Judy) Chia.

As previously reported in the G&G Lab Notes section, significant amounts of melee-size synthetic diamonds, both HPHT- and CVD-grown, are being manufactured for the jewelry industry. Over the past year, we have seen more instances of synthetics incorporated into finished jewelry pieces.

Recently in GIA's New York laboratory, we examined a diamond ring with 100 colorless melee side stones, each about 0.5 mm in diameter (figure 1). Using the new GIA iD100TM screening device, we were able to screen these melee. The device uses sophisticated spectroscopy technology to distinguish natural diamonds—either loose or mounted—from synthetics and simulants. The operator simply points the probe at a diamond, and the result is given within two seconds. Out of the 100 melee from this ring, one stone was referred by the GIA iD100 for further testing (figure 2).

Figure 2. One stone, about 0.5 mm in diameter, was referred by the GIA iD100TM for further testing. Photo by Sood Oil (Judy) Chia. The inset photo shows a prototype of the iD100.
Upon further examination, the stone was determined to be a type IIa diamond (no detectable nitrogen impurity). Examination in the De Beers DiamondView instrument revealed strong phosphorescence to short-wave UV radiation, typical for HPHT-grown synthetic diamonds (figure 3). Further examination using photoluminescence (PL) spectroscopy detected a very weak silicon impurity and a very high concentration of nickel, often a catalyst used to grow HPHT synthetic diamonds.

Figure 3. The referred melee displayed strong phosphorescence to short-wave UV radiation, as is typical of HPHT-grown synthetic diamonds. Image by Paul Johnson.
This ring offered an excellent example of how the GIA iD100 can quickly screen very small mounted diamonds and accurately detect any synthetics or even simulants. Source: GIA @topic:4


Title: Hong Kong Show 2017: Demand Improved, But Still Spotty Abstract: The 2.11 ct cushion cut Argyle Everglow Fancy red diamond is the centerpiece of the 2017 Argyle Pink Diamond Tender. The highlights of the collection were displayed at the Hong Kong show. From left: the Argyle Kalina, a 1.50 ct oval shaped Fancy Deep pink; the Argyle Avaline, a 2.42 ct cushion cut Fancy purple pink; the Argyle Everglow; the Argyle Isla, a 1.14 ct radiant shaped Fancy red; and the Argyle Liberte, a .91 ct radiant shaped Fancy Deep gray violet. Photo courtesy of Rio Tinto.

Demand for loose diamonds was stronger than expected at the September 2017 Hong Kong Jewellery & Gem Fair. Most was centered in very specific sizes and qualities, with the market favoring larger companies that carried a full range of goods. Smaller firms that serve market niches found business very slow if they did not have goods to match specific requests.
Demand was strongest for larger (3-plus ct) sizes and medium qualities - I to K colors and SI clarities with Excellent cut grades. The Chinese market is starting to revive, but buyers remained price-conscious and avoided the top colors, exhibitors said.
The reason for such selectivity is that inventory levels of polished stones remain quite high, so retailers were buying only goods for which they had an immediate need.
“Demand has improved,” said an executive of one major diamond firm. “But it’s still not high enough to offtake current inventories in any meaningful way.”
Inventories continue to concern banks serving the diamond industry. Three years ago, most of those banks instituted a requirement that a third party auditing firm must confirm the values of inventories. De Beers and other producers have instituted the same requirement “to ensure their knowledge of diamond stocks is accurate,” said the executive.
Fancy color diamonds remained a staple of the Hong Kong shows, but still-lofty prices put a damper on buying. Prices for fancy pinks, blues and top yellows have remained stable in the past two years, which removes the urgency to “buy now or pay more later,” dealers said. In reality, dealers have little room to maneuver on prices because competition to buy these stones from producers remains intense, along with the prices.

Attendance was up at both Hong Kong September shows. Demand for loose diamonds was stronger than expected, but buying was cautious for gemstones and finished jewelry. Photo by Russell Shor/GIA
ARGYLE PINK DIAMONDS
Argyle previewed its 2017 pink diamond collection at the Peninsula Hotel in conjunction with the Hong Kong show. The centerpiece of the collection is a 2.11 ct GIA-graded Fancy red, VS2 diamond Argyle calls the Argyle Everglow, named after a song by the British group Coldplay. The cushion cut diamond attracted most of the attention at the gathering.
The four other diamonds from the 58-stone collection on display were: the Argyle Isla, a 1.14 ct radiant cut Fancy red; the Argyle Avaline, a 2.42 ct Fancy purple-pink; the Argyle Kalina, a 1.50 ct. oval Fancy Deep pink; and the Argyle Liberte’, a 0.91 ct. Fancy Deep gray-violet.
ALROSA DIAMONDS
Alrosa conducted its annual tender of polished and rough diamonds at the show. The centerpieces of the tender were the five D, VVS1 “Dynasty Collection” diamonds cut from the 179 ct The Romanovs rough diamond found two years ago. The largest stone is a 51.38 ct round brilliant, followed by a 16.67 ct pear shape, a 5.05 ct oval, a 1.73 ct pear and a 1.39 ct oval.
Alrosa’s deputy director of sales, Evgeniy Tsybukov, said the rough was approximately oval shaped but had a feather that would make the polished an SI clarity.
“We studied the diamond for six months, deciding whether or not to try for a 100 carat oval,” he said. “Then we decided to make multiple diamonds from the stone.
The Dynasty collection diamonds will be sold via online tender in October.
SYNTHETIC DIAMONDS
Synthetic diamond sellers took several spaces at the show, but prominent signs at the entrances to the diamond hall at the Asia World Expo announced that many of the 1,000 + diamond firms exhibiting had pledged to sell only natural diamonds. Accordingly, the companies selling synthetic diamond were housed across the hall in the colored stone area.

These carved Paraíba-type tourmalines weigh a total of 58.08 carats and were offered by Kleinman & Co., San Francisco.  Photo by Russell Shor/GIA
COLORED GEMS
Demand for colored stones, pearls and finished jewelry was slow for the second straight year according to exhibitors, as the Chinese market continues to struggle with a reduction in demand for luxury products.
Dealers reported that sales of higher quality, untreated ruby, sapphire and emerald were better than last year, though nowhere near the levels of three years ago. Demand for quality jade also rebounded from last year, despite continually lofty prices.
Requests for treated stones were very slow, they said, and even less so for heavily treated low-priced goods, such as glass-filled ruby and diffusion-treated sapphire.
There was much more Paraíba-type tourmaline offered at this show than previous years, mostly at high prices, except for the obvious greenish material. By contrast, tanzanite, which had been shown in abundance at previous shows, was scarce.
Traffic at the finished jewelry section of the show in the Hong Kong Convention Centre was much stronger than last year, but business was concentrated on the high end. Exhibitors selling more commercial lines said orders tended to be cautious and limited – filling in inventory of popular items. Source: GIA @topic:8


Title: Cautious Outlook for Fall; Gemfields Accedes to Takeover Abstract: A worker sorting emeralds at Gemfields’ Kagem mine in Zambia. Photo by Russell Shor/GIA

With rough inventories on the increase and financing for diamond companies growing more elusive, De Beers and the other major diamond producers will be approaching the summer and early fall sales periods with caution.
De Beers and Alrosa both have cycle sales (sights) set later this month and most industry watchers believe there will be reductions from June’s allocations.
De Beers did not announce a price increase at its June sight, but its clients did find some types of goods slightly more expensive, based on stronger-than-expected demand at the JCK show in Las Vegas. The sight and side sales totaled $530 million for June, a bit more than the May totals, which were $522 million.
De Beers’ executives said demand for rough was good, “following positive feedback from the Las Vegas show and in line with other trends.”
Alrosa’s June rough diamond sales totaled $354.4 million, slightly down from the June 2016 total. The company announcement, which also gave six-month total rough sales of $2.44 billion, said the market is “stable, though there was a seasonal slowdown at the end of June.”
In the weeks since Las Vegas, however, retail sales, including jewelry, have remained slow in the U.S. New taxes on the trade in India and a tug-of-war between a bank and a major Antwerp diamond firm have undercut confidence.
The Indian government imposed a 0.25% tax on rough diamond imports in June, which took effect this month. The country’s diamond manufacturers denounced the tax, saying profits are already under extreme pressure and that this tax could cause some to start losing money and shedding workers.
FINANCES
In Antwerp, KBC Group Bank and diamond manufacturer Excelco are at odds over $29 million in outstanding loans, resulting in a see-saw battle over its assets. Excelco is a leading Antwerp manufacturer and former De Beers’ sightholder that supplies a number of U.S. retail chains.
Originally reported by Bloomberg News, KBC, which is winding down its diamond portfolio, obtained an order earlier this month to have the company’s assets seized from its Antwerp offices. This followed a seizure of company assets held by De Beers and ABN Amro bank. Exelco reportedly owed KBC $29 million.
On July 6, however, a Belgian court ordered KBC to return all of the company’s assets, claiming it was on-track to repay its loan by 2020, as contracted.
COLORED GEMS
The not-quite-friendly takeover of Gemfields by its largest shareholder, Pallinghurst, is not expected to have a significant impact on the gemstone mining company’s operations. As it reverts to a privately held company, however, the gemstone world could lose an important source of information.
In fiscal 2016, which ended in September of that year, Gemfields:

Ruby: 10.3 million carats of both high quality and commercial grade from its 75%-owned Montepuez mine in Mozambique. Sold for $73.1 million.
Emerald: 30.1 million carats of high and commercial grade from its 75%-owned Kagem mine in Zambia. Sold for $101 million. Gemfields claims Kagem accounts for 25% of the world emerald production by volume.
Amethyst: 964,548 kilograms from its 50% stake in the Kariba mine in Zambia. Sold for $660,000.

A Gemfields’ survey of the global colored gemstone market in 2016 reported that world sales of gemstones and cultured pearls totaled an estimated $8.4 billion; 69% of that amount were ruby, sapphire and emerald.
Gemfields’ executives had advised its shareholders to reject Pallinghurt’s offer because it “significantly undervalued Gemfields and its prospects as a leading player in the colored gem sector.”
The company also owns Fabergé, the luxury jewelry manufacturer (2016 sales were $11.8 million). Source: GIA @topic:8


Title: Economists See Bright Holiday Season Abstract: Burmese rubies, such as these, were banned from import into the U.S. from 2008 until President Obama lifted sanctions on them on Oct. 7. This 17.30 gram crystal in calcite (center), was found in Kyauksaung, Myanmar and was presented to the GIA museum by William F. Larson. The three Burmese rubies in front of it, (left to right) are: a 1.77 ct. oval cut, a 2.21 ct. cushion cut and a 6.32 ct. oval cut. They are courtesy of Edward Boehm. Photo by Robert Weldon/GIA.

	While jewelry sales have been fairly flat in the U.S. this year, the National Retail Federation (NRF) is predicting a strong 3.6% increase for all retail in the coming holiday season. The NRF said consumer confidence is on the rise, jobs have become more plentiful and incomes have been climbing. All of these factors will push growth higher than the 10-year average of 2.5%.

	Economists at financial institutions are even more bullish on the season, the Centurion newsletter reported. The accounting firms of Deloitte and PriceWaterhouseCoopers (PWC) both anticipate strong gains. PWC is calling for a 10% increase, citing a consumer survey that also found consumers favoring independent stores and local brands.

	U.S. jewelry retailers could use the good news. In the first half of the year, Tiffany & Co. same store sales were down 9%, Blue Nile sales were flat and Signet Group (Kay, Zales, Jared Galleria) were down 2.5%.

	Worldwide, luxury sales have been struggling with Swiss watch demand showing monthly declines for over a year, especially at the higher end. Richemont (Cartier, Van Cleef & Arpels, and several luxury watch companies, including Baume & Mercier and Vacheron Constantin) was down 16% through the first half. LVMH (De Beers retail and Bulgari) was a bright spot, showing a 4% gain, mainly from the introduction of several watch lines.

	COLORED STONES

	U.S. President Obama removed the ban on imports of ruby and jade from Myanmar (Burma) on Oct. 7 during a visit by State Counsellor of the Republic of the Union of Myanmar Aung San Suu Kyi. The move may contribute to a revival of ruby mining in Mogok and Mong Hsu, which reportedly had declined significantly after the 2008 ban was enacted.

	There was no real consensus among dealers on how this action will affect the ruby market. Many believe the Burmese deposits have been winding down and that the ban (at least for Mogok stones) was widely ignored in the past few years. Others maintain that the ban, coupled with production cuts, sharply curtailed ruby supplies in the U.S. and prompted some prominent retailers, Tiffany & Co. in particular, to stop selling the gemstone.

	NGOs protested the decision, noting that human rights in Myanmar are still threatened by the military clique that still has a grip on much of the country’s economy, and the continuing violence against the Shan people, an ethnic minority concentrated in the Mong Hsu region.

	DIAMONDS

	De Beers sold $485 million worth of rough diamonds at its Sept. 26-29 cycle (previously called sight), raising prices 1% to 2% on goods that would polish out to a carat or larger and lowering them slightly for melee-sized stones. The total was slightly larger than expected given the continuing credit problems in the diamond industry and the upcoming Diwali holiday in India, where manufacturing operations close for two weeks or more.

	Russia’s Alrosa sold $454 million worth of rough and $18.9 million in polished in September, nearly double the August totals for rough diamonds, which was $243 million. August polished sales were $12 million. Alrosa’s second half sales are 58% above comparable 2015 levels, which were marked by oversupplies and buyer revolts over high rough prices. First half sales were 23% higher by value, 21% higher by carat volume. Source: GIA @topic:8


Title: The Wittelsbach Blue Abstract: The 35.56 ct Wittelsbach Blue is one of the largest historic blue diamonds ever fashioned. It belonged to the Bavarian House of Wittelsbach and was displayed in the Treasury of the Munich Residence until it disappeared in 1931. It was secretly sold in 1951, “rediscovered” in 1961, and then sold again in 1964 to an undisclosed private buyer. In December 2008, the Wittelsbach Blue was sold at Christie’s London to jeweler Lawrence Graff for just over $24.3 million, a record price for any diamond at auction. This article describes what is known about the Wittelsbach Blue since it was first reported in 1666, and the gemological information released to date on this diamond, which was recently graded Fancy Deep grayish blue. Investigations in the historical archives of Bavaria, Austria, and Spain revealed that there is no archival evidence to support many previous statements about this stone.

	DATA DEPOSITORY

Inventory of the Munich Treasury, 1774
	Winter, 2008 Source: GIA @topic:4


Title: Fall 2009 G&G Book Reviews Abstract: “Famous Diamonds, 5th Ed.”
By Ian Balfour, 335 pp., illus., publ. by Antique Collectors’ Club [www.antique-acc.com], Woodbridge, Suffolk, UK, 2009. $95.00

	“Cameos: Old & New, 4th Ed.”
By Anna M. Miller, edited by Diana Jarrett, 382 pp., illus., publ. by Gemstone Press [www.gemstonepress.com], Woodstock, VT, 2009. $19.99

	“Sapphire Mining in Madagascar”
Contributions to Gemology No. 8, 46 mins., released by GRS Gemresearch Swisslab [www.gemresearch.ch], Lucerne, Switzerland, 2009. $40.00

“Profiting by Design: A Jewelry Maker’s Guide to Business Success”
By Marlene Richey, 135 pp., illus., publ. by MJSA Press [www.mjsa.org], Providence, RI, 2008, $34.95

“Cristalli: L’Ordine dal Caos [Crystals: Order from Chaos]”
By Adalberto Giazotto, Federico Pezzotta, and Giovanni Pratesi, 240 pp., illus., publ. by Giunti Editore [www.giunti.it], Florence, Italy, 2008 [in Italian], 48.00

“Gill’s Historical Index”
By Joseph O. Gill, 647 pp., illus., publ. by the author [www.archive.org, search for “Joseph Gill”], 2009, Free

To view the full section, download the PDF above.

	DATA DEPOSITORY

Famous Diamonds, 5th edition - Additional Material
	Fall, 2009 Source: GIA @topic:10


Title: Hoop Dreams: NBA Championship Rings Abstract: You need world-class skill, teamwork and inspiration to win an NBA championship. You need the same qualities to make a NBA championship ring.
	To find out what it takes to make an NBA championship ring, we interviewed executives at Jostens and Jason of Beverly Hills. Both companies have designed and manufactured these ultimate status symbols for professional players.

	Jostens is one of the most prolific producers of championship rings. Its resume includes 46 NBA championship rings, 31 Super Bowl rings, Major League Baseball World Series rings, National Hockey League Stanley Cup championship rings, NASCAR rings, Major League Soccer championship rings and hundreds of college and high school championship rings. It most recently designed and made NBA championship rings for the Miami Heat, winners of the 2011-2012 and 2012-2013 seasons.

	The Miami HEAT ring posed a unique design challenge. Recreating the logo – 0.5 carat diamond basketball swooshing through a net – was particularly difficult, according to Jostens. The ring also had a secret message on the side panel. Underneath the Larry O’Brien trophy are 16 lines made of 14K gold. Head coach Erik Spoelstra brought a trophy into the locker room when the team made the playoffs. He told the players that they needed 16 games to become champions, and each time the team won a game, he put a notch in the trophy.

	Jostens’ 2013 NBA championship ring for the Miami HEAT was equally impressive: It boasted 10.3 carats worth of diamonds – the current record holder for the largest amount of diamonds in a Jostens’ basketball championship ring.

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	Jason of Beverly Hills has made three NBA Championship rings since 2009. The company most recently crafted the 2014-2015 Golden State Warriors championship ring (Steph Curry proudly wears it), and the 2008-2009 and 2009-2010 rings for the Los Angeles Lakers.

Golden State Warriors Championship Ring for the 2014-2015 Season. Courtesy: Jason of Beverly Hills.

	More than 6 carats of diamonds and blue sapphires decorate the 2015 NBA championship ring for the Golden State Warriors. It also features impressive workmanship, symbolism and hidden messages.

	The 240 diamonds in the ring stand for the team’s wins under the current ownership. The circular top is a nod to the shape of the Warriors jersey logo and the shape of a basketball. The custom-made 67% pure gold (approximately 16K) used in the Golden Gate Bridge and the players’ numbers represent the Warrior’s 67 wins in the season.

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	Designing the Ring

	Designing an NBA championship ring is a sprint in creativity and skill. Once the final shot is taken, Jostens and Jason of Beverly Hills rush to beat another buzzer: they will have about four months to design and make the ring, which is presented to the players on opening day of the next season. Designs are shown to the team. The team owners pick a vendor. A budget is set for the entire project and the amount to be spent on each ring. This varies from team to team.

	Jason of Beverly Hills starts designing as soon as the game clock winds down. When creating the ring for the Golden State Warriors, its designers hand-sketched a concept they thought would wow the players. This was made into a 3D CAD model. Jason of Beverly Hills then met with Steph Curry, Draymond Green and Andre Iguodala to refine the design. Owners Joe Lacob and Peter Guber provided additional suggestions. The company integrated all the input, creating a design that captured the identity of the team.

	Jostens uses a different approach. When the final four teams face off in the NBA playoffs, its designers create mock-ups for all of them. This way they are ready to present designs – no matter who wins. The Jostens’ design team shows its initial renderings to the winners. Players share pivotal moments and events from the season. The owners tell what elements they want in the ring. Jostens then returns with final designs about three to four weeks later. The goal is to make the championship story come to life in gold, diamonds and other gemstones.

	Crafting the character of a championship season may have been a little easier for Jostens during the 1990s, when the Chicago Bulls won six championships. Jostens designed all these rings, so they knew something about the franchise, its owners and the team. Owner Jerry Reinsdorf and his wife collaborated closely with Bulls star Scotty Pippen to create the design for the 1993 Chicago Bulls NBA championship ring, which Michael Jordan proudly wears.

Creating a 3D Bulls logo was a demanding task. It features a man-made red stone that required impressive design skills to make and set it. © Jostens, Inc.

	Manufacturing the Ring

	When designing the ring, Jostens uses a 13-step process that combines old-world craftsmanship and the latest technologies. Hand sketches are turned into CAD/CAM layouts. Manufacturing is anchored in the lost wax process (a wax model of the ring is encased in material and burned away before molten metal is poured into the cavity), which is used along with 3D printing. Every ring is handcrafted and customized for each wearer. The company believes that this blending of old and new allows them to offer a superior product.

	Ring sizes vary, from as small as a size five for a smaller person who works at the franchise, up to 23 for the players. The company has master tools that allow them to create rings of all sizes.

	When Jason of Beverly Hills makes the rings, the table for every piece has the same circumference. The ring sizes, however, are scaled for each individual. All rings are made in-house; it takes six to eight weeks to manufacture all of them.

	As for gems, Jostens uses natural diamonds, sapphires, rubies and emeralds in its NBA championship rings. Synthetic stones may be used on occasion, either to match the specific Pantone color of the franchise’s uniform or for gemstones that must be custom cut into complex shapes. The goal, however, is to use a natural gemstone whenever possible.

	“We use colored gems to create the team’s logo and other design elements. This is a relatively new trend in championship rings, which only used to feature diamonds. The Boston Red Socks and St. Louis Cardinals are two recent examples where we used rubies to create the logo,” said Chris Poitras, vice president, sports marketing and development at Jostens.
Jason of Beverly Hills has used only natural stones in the three NBA rings it created. Gems are sourced from around the world and are typically cut in Canada.

	As for metals, 14K white gold is the most common choice, according to Jostens. Platinum and yellow gold are occasionally used. Jason of Beverly Hills shared that 14K white and yellow gold are the most popular metals. Poitras predicts that yellow gold will be making a comeback in the next year or so.

	Evolution of NBA Championship Rings

	Championship rings have changed over the decades. According to Poitras, “Championship rings have changed from simple symbols of victory to a sophisticated extension of the team’s brand. Since these brands are iconic, the logo, font and important moments are worked into the design, making the finished product a retelling of the team’s path to victory and a reflection of the franchise.”
Turning the ring into a brand extension requires a larger canvas, and that means a larger ring. Bigger athletes have also contributed to ever-increasing ring sizes. The Boston Celtics 1969 NBA championship ring by Jostens is a dramatic example of how they’ve evolved.

Considered cutting edge at the time because a diamond was set on top of the basketball crest, the Boston Celtics ring features a 0.5 ct diamond set in 10K yellow gold. ©Jostens, Inc.

	Jason of Beverly Hills sees the bling factor as the primary driver behind bigger rings. “Every owner is trying to outdo each other with a bigger and better ring,” said Jason Arasheben, jewelry designer and owner of Jason of Beverly Hills.

	Personalizing the Ring

	NBA championship rings are a study in personalization. A player’s name and jersey number are usually engraved in the shank. The number of gemstones used may represent the number of players on the team roster or a key milestone in the team’s season or history. The team’s motto, jersey numbers of the players, final scores of important games, and other significant details are subtly incorporated into the design.

The 14K white gold ring Dallas Mavericks championship ring has more than 250 brilliant round and princess cut diamonds with a total weight of approximately 10 carats. ©Jostens, Inc.

	Jostens’ 2011 NBA championship ring for the Dallas Mavericks is an example of this impressive craftsmanship and rich symbolism. Six individual pieces were needed to make the Mavericks’ logo, part of the 14 total ring components. Another 31 custom princess-cut diamonds surround it, representing each year the Dallas Mavericks have been in the NBA. Flush set around the rest of the ring top are round brilliant diamonds.

	The player’s name and a single star appear on the side panel, which symbolizes the Mavericks’ first championship. The other side panel has a star set with one round brilliant diamond. The Mavericks “M” is set with 15 round brilliant cut diamonds representing the 15 players on the championship roster.

	Designing the ring was an impressive dash to the finish line. An NBA work stoppage prevented Jostens from talking to the players to get their input on the design. When they finally could, the company had just 17 days to design the ring.

	“NBA championship rings are becoming more like elaborate wearble pieces of art,” said McKenzie Santimer, GIA manager of museum exhibits.

View Gallery

	All NBA championship rings made by Jostens and Jason of Beverly Hills come with lifetime warranties. Jostens notes that, as great care is made in making the rings, they are rarely returned for repair. If a ring is ever damaged, players contact their dedicated customer service representative.

	Personalizing the L.A. Lakers Rings

Jason of Beverly Hills used 15K gold for the L.A. Lakers 15th championship. Courtesy: Jason of Beverly Hills

	When the L.A. Lakers won its 15th championship for the 2008-2009 season, Jason of Beverly Hills set 15 large round brilliant diamonds weighing 2.85 cts. on the table to commemorate it. The company also used 15K gold to celebrate the milestone.

	The Lakers' rings mirror the shape of the exterior of their home arena, the Staples Center. When viewed from the side, the "roof" and "sides" are visible.

	Every player’s face was etched in into the side of the ring. CAD/CAM and 3D printing was used to create the images. Kobe Bryant and his team members are each immortalized in their own ring.

Sixteen over-sized round brilliant diamonds on the table symbolize the 16 historic Lakers' championships. Continuing the theme of “16,” Jason of Beverly Hills alloyed 16K gold for the ring. Courtesy: Jason of Beverly Hills

	Jason of Beverly Hills also created the NBA championship ring for the 2009-2010 L.A. Lakers. It has two trophies that represent the back-to-back championships.

	A clever touch: A piece of the basketball from the winning game is forever preserved in the ring.

	The NBA Championship Ring Ceremony

	Under the bright lights of opening night of the new season, the players receive their rings. So does everyone who works for the franchise. It’s a thrilling moment. The championship ring is now a permanent tribute to the accomplishment of the past season.

	Jason of Beverly Hills added a bit of pizazz to its presentation. Each player was given a box that had a motorized turntable and built-in lights to illuminate the ring. This turned the box into something between a museum display case and a nightclub dance floor.

	A new season will begin in the fall and all 30 teams will compete to win the Larry O’Brien trophy. Only one will walk away victorious. And the process of crafting the NBA Championship ring will start all over again. Source: GIA @topic:9


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). Source: GIA @topic:8


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. Source: GIA @topic:1


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. Source: GIA @topic:4


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. Source: GIA @topic:4


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! Source: GIA @topic:8


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. Source: GIA @topic:10


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. Source: GIA @topic:6


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. Source: GIA @topic:7


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. Source: GIA @topic:4


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. Source: GIA @topic:6


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. Source: GIA @topic:8


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. Source: GIA @topic:8


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. Source: GIA @topic:8


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 Source: GIA @topic:8


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. Source: GIA @topic:1


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. Source: GIA @topic:3


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.” Source: GIA @topic:6


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. Source: GIA @topic:11


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. Source: GIA @topic:7


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). Source: GIA @topic:1