Publish Year: - Title: Yellow Gemstones: Can You Identify Them? Abstract: This 54.29 ct Fancy Intense yellow cushion cut diamond is accented with 67 cts of white diamonds and is set in 18K white gold. Courtesy of Chatila. Photo by Robert Weldon/GIA

Sunshine, lemons and a variety of flowers share the color yellow and often evoke feelings of happiness, warmth and optimism. A variety of gemstones also come in shades of yellow, from diamonds to citrine to garnets.
Yellow diamonds are enduring in quality and value and popular set in jewelry. Yet a treasure trove of other yellow gemstones exists at reasonable price points. They can be found in light-toned shades to rich, warm hues.
The most plentiful yellow gemstones in the marketplace are citrine, sapphire, topaz, tourmaline, and transparent opal. Other varieties include yellow andradite garnet, spessartine and Mali garnets, beryl, sphene, zircon, spodumene and transparent varieties of labradorite and orthoclase feldspar. Less abundant or collectible yellow gems include chrysoberyl, sphalerite, apatite and prehnite.
Yellow Gemstone Challenge
Many yellow gemstones can resemble one another in color. Can you see the subtle differences in the yellow gemstone pairs? They appear similar, but are different species.

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Yellow Diamonds
Yellow is the most abundant color of natural fancy diamonds, yet they still represent a very small percentage of all diamonds. The first major source of yellow diamonds was found in the late 1860s in Cape Province, South Africa, so in the jewelry trade, these yellow diamonds came to be known as “cape” yellow diamonds.

The cut fancy yellow “cape” diamond, front, is a gift of Safdico USA, Inc. The “cape” yellow diamond hexoctahedron rough, back, is a gift of the Sir Oppenheimer Student Collection. Composite photo by Orasa and Robert Weldon/GIA
“Cape” diamonds, according to the “GIA Diamond Dictionary,” are a Type Ia diamond with a distinct yellow body color that exhibits absorption that falls in a specific and defined pattern. (There is often a strong band at about 415.5 mm and a fairly strong one at 478.0 nm, with four weaker lines between the two.) Such diamonds may also fluoresce blue, yellow, or orange.
What is the cause of the yellow color in diamonds?
“In general, the presence of nitrogen atoms gives rise to two kinds of absorption in the blue region of the visible spectrum; the remainder of the spectrum is transmitted, leading to an observed yellow color,” according to GIA’s diamond color expert John King.

The color of this 9.05 ct Fancy Vivid yellow diamond is evenly distributed throughout the face up appearance of the stone. Courtesy of B. Najjar. photo by Robert Weldon/GIA
Canary is a historic term for a Type Ib fancy color intense yellow diamonds that is used to distinguish them from diamonds with a “cape” spectrum. Diamonds referred to in the trade as “canary yellow” are highly valued for their saturated yellow color.
Famous Yellow Diamonds

Schlumberger’s rosette necklace with ribbon clip features the famous Tiffany Yellow Diamond. Photo courtesy of Tiffany & Co.
There’s an inexplicable allure about diamonds that fascinates the gem lover. As early as 1676, accounts by the French traveler and gem dealer, Jean-Baptiste Tavernier, mentioned seeing a 137.27 ct yellow diamond that he referred to variously as the Florentine, the Austrian Yellow and the Grand Duke of Tuscany. Since then, many notable color diamonds have been given the elite distinction of famous diamonds, particularly as the appeal of color became widespread.
The Tiffany Yellow Diamond was acquired by Tiffany & Co. in 1878 and has been on display for more than 70 years in its flagship store in New York. Under the direction of Dr. George Frederick Kunz, it was cut from a 297.42 ct rough stone to its present cushion cut of 128.54 ct, one of the largest known fancy yellow diamonds in the world. GIA graded it in 1984.

The Allnatt, 101.29 cts, is a famous Fancy Vivid yellow diamond that improved in color and value by being recut. Photo by Shane F. McClure/GIA
The Allnatt, a yellow diamond thought to have originated from the De Beers mine in South Africa, is named for its former owner, Major Alfred Ernest Allnatt, a British soldier and noted philanthropist who purchased the diamond in the early 1950s.
The diamond next appeared at Christie’s Geneva auction in May 1996 weighing 102.07 ct with a color grade of Fancy Intense yellow. It was purchased and then recut to 101.29 ct to improve color and clarity, going from Fancy Intense to Fancy Vivid with an improved clarity grade to VS2.
The Allnatt is a classic example of early 20th century cutting styles used to retain maximum weight and enhance the color of a well-formed octahedral rough crystal.

The famous Kahn Canary Diamond is set in an 18K gold and platinum ring, designed and created by Henry Dunay, a prominent New York jeweler. The graceful billowy shape of the diamond was left uncut. Courtesy of the Stanley Kahn Family Collection, Pine Bluff, Arkansas. Photo by Harold & Erica Van Pelt/GIA
George Stepp, a logger from Carthage, Arkansas, found a yellow diamond crystal in the Crater of Diamonds State Park in Arkansas in 1972 and sold it to Kahn Jewelers in Pine Bluff, Arkansas, where it was left uncut to showcase its natural triangular pillow shape known as a macle crystal. “The Kahn Canary Diamond” weighs 4.25 carats and is internally flawless.
More than 33,000 diamonds have been found in the Crater of Diamonds State Park in Arkansas since it became a state park and opened to the public in 1977. The park has a “finders, keepers” policy that allows the public to dig for diamonds for a fee. @topic:10


Publish Year: - Title: Ups and Downs of 2016 Make for an Uncertain 2017 Abstract: Rough diamond prices are more in touch with the market going into 2017, but some analysts believe a new supply glut is building. Photo by Russell Shor/GIA

	The diamond industry experienced a slow-growth economic recovery in 2016 and the colored gemstone trade received a welcome shot in the arm − despite a politically turbulent year.

	Luxury brands worldwide experienced a second slow year in a row and, in the U.S., the world’s largest market, jewelry demand fluctuated between anemic growth and slight declines as the fractious presidential election took its toll on the national mood. Consumers in China, the world’s second-largest retail market, continued to cut back on luxuries, sending the country’s major jewelers into a second year of double-digit sales declines. Currency chaos in India sapped demand at the year’s end.

	These mixed signals leave no clear indicators for the state of business in 2017.

	DIAMONDS

	The diamond industry was in chaos coming into 2016. The sharp cutback in rough sales by De Beers, Alrosa and other producers in 2015 helped reduce an estimated eight-month inventory overhang that weakened prices and sapped profits. Rough prices were well above comparable polished in most cases and diamond manufacturers, who saw their credit lines slashed by 30% or more, refused most of their allocations from De Beers and Alrosa.

	Both De Beers and Alrosa trimmed the prices of their contracted sales (an average of 5% and 15%, respectively) at the beginning of the year and other producers followed suit. The recovery was surprisingly swift and manufacturing became profitable again for many firms.

	By the end of 2016, the major mining companies turned in good numbers. De Beers was estimated to close the year with rough sales estimated between $5.6 billion and $5.8 billion, representing a nearly 30-35% increase from a turbulent 2015, despite lowering its rough prices. Alrosa’s sales climbed 48% (to $3.98 billion) during the first three quarters of 2016 and were expected to keep that pace until year’s end. Rio Tinto’s was expected to be 3-5% ahead of 2015.

	These numbers, however, were not good enough to save De Beers’ Snap Lake mine in Northern Canada, which the company plans to flood this year after several years of unprofitable operation. In addition, Rio Tinto walked away from the promising Bunder diamond mining project in India before development began.

	Banks continued to tighten credit terms on the diamond industry in 2016, with the result that some large operations were placed on financial life support. Credit will remain difficult going into 2017 and likely remain so for the foreseeable future.

	Dramatic increases in rough sales were not fully matched by rising demand, so inventories began to climb after the spring season, prompting leading lender ABN AMRO to issue a warning that stocks may reach unsustainable levels. As a result, De Beers and Alrosa will likely remain cautious in their sales during the first quarter.

	After a five-year hiatus, generic diamond advertising was revived in the U.S. The Diamond Producers Association, a group of the world’s seven largest diamond-mining companies, which included De Beers, launched the $12 million program in October using the tagline “Real is Rare.”

	The campaign, which was presented in various social media channels and on TV, shows young couples in clubs and resorts, continuing the relationship-oriented campaigns of the De Beers “Forever” advertising of the past. There are differences between the old and new campaigns, however. The old De Beers ads specifically targeted engagements and wedding anniversaries. The “Real is Rare” campaign is less about formality and traditional rules in today’s relationships and adds the implication that natural diamonds will remain more desirable than synthetics.

	Synthetic diamonds broke into the news early in the year with the creation of the Diamond Foundry, a new venture funded in part by actor Leonard Di Caprio. The start-up began test-marketing its lab-grown diamonds through four distributors and is working on a production facility it plans to open at the end of 2017.

	While colorless synthetic diamonds remained a small part of diamond sales in 2016, producers and sellers of those goods are increasing their marketing efforts and sales channels, so sales likely will grow in 2017.

Rubies from Mozambique helped renew demand for ruby, but some retailers remained cautious until President Obama lifted U.S. sanctions on material from Myanmar. Photo by Russell Shor/GIA

	COLORED GEMS

	President Obama removed the eight-year-old sanctions on Myanmar in the fall, allowing rubies from that country – the world’s major source – to legally be traded again. While some retailers and wholesalers ignored the sanctions, most U.S. major retailers did not carry ruby pieces while they were in place. Although Mozambique ruby helped fill the supply gap in the past two years, some retailers and jewelry designers worried that a cloud of suspicion hung over the gem, regardless of its source, because of its association with Myanmar.

	The ban was less effective at the top end of the market where dealers at U.S. trade shows continued to openly display and promote “pigeon blood” Burmese rubies.

	The effect of the sanctions being lifted may not be felt in consumer markets until later this year because gem dealers need time to re-establish supply lines.

	The Responsible Jewellery Council (RJC) announced in March that it will begin to certify colored stone producers in 2017. The move came after five years of discussions with various players in the trade. The RJC has 900 member firms in the diamond, jewelry and watch sectors of the industry.

	RETAIL

	The retail optimism spurred by the growing U.S. economy did not translate into a sharp upturn in diamond demand through the year. Major retail chains reported uneven sales throughout the year, with slight declines going into the fourth quarter. Most U.S. major retailers will report their seasonal numbers in late January.

	Surveys of independent jewelers showed more positive growth, with the majority enjoying sales increases of 5% or more, especially in the upper market.

	In China, the largest retail jewelers reported continued double-digit sales declines as the market continues to cool. In Hong Kong, retail sales of jewelry and watches fell 19% through the first 11 months of the year, according to the Hong Kong Census and Statistics Department. Officials in China remain hopeful that 2017 may bring an improvement because the government, recognizing the need to spur the economy, is adopting measures to encourage consumer spending.

	India’s retail jewelry sales took an immediate hit in November after its government banned 500 rupee bills (worth approximately $7.50) and 1,000 rupee bills (worth about $15) from cash transactions. The goal was to direct more commerce through banks so the government could keep track of it and reduce the opportunity for corruption, money laundering and tax evasion. A large portion of the population is paid in cash with such notes, however, and do not have bank accounts. Economists estimate that the move will result in sharp cuts in retail sales, including jewelry, and reduce economic growth by one or two points.

	Worldwide luxury sales slumped this year with the slowdown in China and a continued move away from the “bling” look of the past decade.

	Exports of Swiss luxury watches declined 11% through the first 11 months of 2016, with the decline accelerating in the fall. The conditions caused hundreds of layoffs throughout the industry. Executives said they are continuing to adjust to a “new reality” of changing tastes and markets.

	AUCTIONS

	The spring 2016 auction season was one for the record books, achieving nearly $800 million in sales between March and July, and featuring the costliest gemstone ever to go under the hammer at a public sale.

	Christie’s and Sotheby’s, who control more than 90% of top-end gem and jewelry sales worldwide, broke last year’s record by more than $140 million, aided by the Oppenheimer Blue, a GIA-graded Fancy Vivid blue diamond that sold for $57.1 million.

	The first major stone to sell last year was the 10.10 carat (ct) Fancy Vivid blue De Beers Millennial 4 diamond. The stone was part of De Beers’ famed diamond collection of 10 blue diamonds exhibited at the London Millennial Dome in 2000 that was the target of a bold, but unsuccessful robbery attempt.

	The fall season began slowly with several important diamonds and gemstones going unsold. It was ultimately successful, however, with a number of multi-million-dollar fancy-color diamonds changing hands, even if the prices did not set records.

	At Christie’s Nov. 29 Hong Kong sale, a GIA-graded 4.29 ct Fancy Vivid blue diamond sold for $11.8 million, while the 10.7 ct “Ratnaraj” ruby sold for $10.2 million. At Sotheby’s Geneva sale, which totaled over $136 million, the 8.01 ct “Sky Blue” diamond, graded Fancy Vivid blue by GIA, drew a winning price of just over $17 million and a 7.74 ct Fancy Deep blue diamond went for $3.7 million.

	The most publicized auction of the year was the June 29 auction of the 1,109 ct Lesedi la Rona diamond, the second largest gem rough ever found. The mining company that found the diamond, Lucara Diamond, offered it in a public sale through Sotheby’s, but it failed to meet its reserve, reportedly set at $82 million.

	The company said it will offer the diamond for sale again this year in a trade-only transaction that presumably would not include a 12% buyer’s premium. @topic:7


Publish Year: - Title: 2016 Hong Kong Show: Demand Slightly Up Abstract: Buyers convene for the diamond and gem portion of the Hong Kong Gem and Jewellery Show at Asia World Expo. The finished jewelry portion of the show is held at the Hong Kong Convention Centre in the central part of the city. Photo by Russell Shor/GIA

	Demand for diamonds and colored gems at the Sept. 13-19 Hong Kong Gem and Jewellery Fair exceeded the expectations of most exhibitors, even if some of the demand came from other dealers bargain hunting from their colleagues in need of cash. Most dealers reported an improvement from last year’s business.

	Chinese retailers and wholesalers believe consumer demand in China is starting to stabilize at a sustainable trading level after two years of market correction following a decade of double-digit growth. In diamonds less than a carat, demand centered on medium colors and clarities. Dealers reported a slight upturn in demand for better quality diamonds over three carats. Price was still a major issue with hard bargaining over relatively small differences, delaying a lot of deals.

	In colored stones, demand still focused on finer colors for ruby, emerald and sapphire, with continuing strong demand for popularly priced gems, such as amethyst and citrine.

	As with last year, the stronger dealers began the show by buying a lot of goods from colleagues in need of hard cash after finding their credit lines severely reduced or cut off entirely.

	As one major dealer noted, “In the past, there were sellers offering big discounts, which pushed down prices for everybody. If we buy them first, it helps us maintain prices.”

	Paspaley Pearling Company held its annual tender auction of South Sea white cultured pearls and golden cultured pearls from the Philippines on the final two days of the Hong Kong show. Demand for both varieties remained similar to last year, an executive from the company said.

	Dealers from around the world inspect lots of South Sea and golden cultured pearls at the Paspaley pearl auction held in conjunction with the Hong Kong Gem and Jewellery Show. Photo by Russell Shor/GIA

	DIAMONDS

	Demand at De Beers’ Aug. 29-Sept. 2 sight (cycle) was strong, according to the company. The $630 million total includes all sales – tender auctions, side deals (called “ex-plan”) and sight sales. De Beers made no announcement about prices, which means they remained steady.

	This sight is the last of the year in which the rough diamonds can be polished in time to reach key U.S. and Asian markets in time for the end-of-year holidays.

	The total is considerably higher than July’s cycle of $528 million; the final three sales of the year likely will show strong increases over last year’s numbers when the market was in extreme turmoil and many clients were refusing goods.

	Alrosa, the world’s largest diamond producer by volume, reported that its first half sales totaled 21.7 million carats, a 21% increase over 2015. Its revenues were up 46% over the same period.

	In a surprise announcement, Rio Tinto bailed out of the Bunder diamond project in Madya Pradesh, India. The final stages of sampling were complete and estimates indicated that it would yield about 27.4 million carats over its lifetime from a cluster of eight kimberlite pipes. Rio Tinto built a highly automated recovery plant to process the samples, along with ore from the mine, after start-up.

	Rio Tinto’s then-CEO Sam Walsh called on India’s Prime Minister Narendra Modi in 2013 to help expedite the approvals process for the project. As late as July of this year the company was issuing optimistic reports that it would begin production in 2019, but later in the month Jean-Sebastien Jacques replaced Walsh as CEO. The company announced it would sell Bunder as a cost-cutting move in August.

	A report in Bloomberg said that several large companies have cancelled development plans in India because of costly, drawn out approval processes and land acquisition procedures.

	This was the second major diamond project to be scuttled this year. De Beers closed Snap Lake in northern Canada earlier in the year because it had become unprofitable. The company is still seeking a buyer.

	Signet Group, the parent company of Kay Jewelers, Jared Galleria and Zales, reported that its second quarter same-store sales were down 2.3% from the same period last year. For Kay Jewelers, the average transaction price fell by 0.8%, but rose slightly for the Zale division, which generally trades at a lower market segment. A statement from chairman Mark Light noted that sales were particularly depressed in “energy-dependent” areas of the U.S., referring to regions where oil and gas production is a significant part of the economy. In addition, stagnant wages and a general malaise in the national mood have dampened demand for luxury goods.

	Tiffany & Co. saw its second quarter same store sales fall by 9% worldwide. Declines were steep in every major market: 8% in North America; 6% in Asia-Pacific; and 17% in Europe. The company cited “well-known” economic factors for its sales decline, as well as a steep decline in Chinese tourism that has had a worldwide impact on the company’s revenues. @topic:7


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

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

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

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

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

	But that was just the beginning.

	The Questions Behind Cut

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

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

	Development of the Cut Grading System

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

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

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

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

	A Final, Predictive Grading System

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

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

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

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

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

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

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

	Putting It All Together

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

	In the same manner, GIA recognized that more than just face-up attractiveness should be incorporated into the assessment of overall cut quality. Quality in design and craftsmanship (as evidenced by a diamond's weight ratio, durability, polish, and symmetry), even when face-up appearance is barely affected, should be considered in a diamond's final cut grade. @topic:10


Publish Year: - Title: After a Century, Riches Still Flow from Cullinan Mine Abstract: A 29.6 carat blue diamond was recovered from the Cullinan Mine in January 2014. Photo courtesy of Petra Diamonds

	South Africa’s Cullinan Mine could be called the greatest treasure trove the world has ever known and, 111 years after its first diamonds were found, it is still yielding major gems.

	Last week, Petra Diamonds, which acquired the mine from De Beers in 2008, unveiled a 29.6 carat “exceptional” blue diamond expected to result in a “diamond of great value and importance,” according to the company.

	The Cullinan Mine (known as the Premier Mine until 2005) first made news in 1905 when workers found a 3,106 carat stone. Named the Cullinan Diamond after the mine’s discoverer, the gem is – to this day ‒ the largest piece of diamond rough ever found.

	The largest diamond cut from it was the Cullinan I, a 530 carat pear shape, probable D color, internally flawless diamond that rests atop the scepter in the crown jewels of Queen Elizabeth II. Through the years, the mine has yielded such famous diamonds as the Premier Rose (353.9 carats rough/137.02 carats polished), The Taylor-Burton (240.8 carats rough/69.42 carats polished), the Niarchos (426.5 carats rough yielded two polishes stones of 128.25 and 39.99 carats) and the Golden Jubilee (755.5 carats rough/545.67 carats polished).

	A number of major blue diamonds have also come from the mine: De Beers’ 27.64 carat (polished weight) Heart of Eternity and 11 other fancy blue diamonds that formed De Beers’ Millennium Collection.  In all, the Cullinan Mine has produced 750 stones weighing more than 100 carats.

	More recently, the Cullinan mine yielded a 26.6 carat blue diamond, cut into a GIA-graded Fancy Vivid blue of 7.0 carats, which sold for $9.49 million, or $1.35 million per carat.

	Petra Diamonds CEO Johan Dippenaar holds the 29.6 carat blue diamond, one of many notable diamonds recovered from the South African mine. Photo courtesy of Petra Diamonds

DIAMOND MARKET: After reasonably successful holiday sales of diamond jewelry in the U.S., De Beers allocated a large sight of about $750 million, with prices of medium quality goods rising 3-5%, higher in some cases. The price increases were apparently based on the assumption that demand for certain goods will increase in the spring when U.S. retailers will need to restock.

	As soon as the news of the price increase reached the markets, premiums on existing rough supplies also began to rise, causing concern that a new round of speculative buying – and subsequent price increases unrelated to demand – may be in the offing.

	Additional buzz from the sight, held in Gaborone, Botswana Jan. 21-24, came from De Beers’ CEO Philippe Mellier’s address that hinted of possible major changes for the sight term that will begin in 2015. He told sightholders De Beers was looking at ways to give them more flexibility, simplify the process and “make sightholder status more meaningful.”

	Diamond dealers take this to mean that De Beers will likely build in more ability for sightholders to adjust the quantities of rough stones in various quality ranges they want to purchase, and make the complex application process much easier. A number of sightholders have publically proclaimed their dissatisfaction with the system and indicated they may not re-apply for a new term.

	Since 2009, De Beers has adjusted to the realities of the post-economic crisis market by allowing clients to defer purchases, but has remained relatively inflexible over whether clients could refuse or defer partial lots of certain categories of goods. The sight application process also requires clients to provide extremely detailed analyses of their businesses.

	Whatever changes may be coming in 2015, the market will have to adjust to a continually challenging environment, especially as far as bank financing is concerned.

	Last year, ABN Amro, the industry’s leading lender, announced it would limit credit to 70% of rough purchases, a break from past policy when they would finance the full amount. In short, diamond manufacturers and rough dealers must put 30% of their own capital up for each purchase, a move the bank feels will limit the speculative buying that has created an extremely volatile rough market during the past four years. In addition, the manufacturers must invest their own funds into rough that is much less profitable to cut in the current environment.

	Bank Leumi’s U.S. subsidiary announced this week that it was exiting the U.S. diamond business, a year after it closed out its Israeli diamond industry portfolio.  A banker quoted in JCK said the industry’s continued lack of transparency, coupled with the stringent regulatory requirements of Basel III, along with other risks, has increased the banks’ reluctance to finance the diamond industry.

	Additionally, some bankers claimed that excessive finance created an unsustainable credit bubble that will ultimately cause some large firms to default. @topic:11


Publish Year: - Title: Building the Color Treated Diamond Market Abstract: VIdeo on Hold for edit

Interview with Rahul Karnavat, Lotus Colors, Inc.

Mr. Karnavat lives in a colorful world, and he shares it with us in these interviews from the 2013 Tucson Gem Show. Presenting a dazzling array of diamonds in a rainbow of enhanced colors, Mr. Karnavat explains his color-enhancing processes one by one.

Sensing the need for colored diamonds in a world with a growing shortage of naturally colored ones, Mr. Karnavat’s company, Lotus Colors, Inc., began irradiating diamonds in the early 1990s. Gradually, they added heat and high-pressure high-temperature (HPHT) treatments and, most recently, a modern coating process.

Mr. Karnavat describes the coatings—actually extremely thin films—at length. He explains that they can result in many lovely colors, but they’re fragile, requiring care in setting, jewelry repair, and other procedures. An advantage of their fragility is that if a color goes out of style, Lotus can just give the color-coated diamonds an acid bath and recoat them in a new, more popular color.

Mr. Karnavat emphasizes the importance of disclosure for all treatments, especially coatings. In his words, “We scare people before we sell it.”

Mr. Karnavat’s company also has a line of jewelry set with their color-enhanced diamonds. It’s only 5-10% of their business, but it helps with sales of the loose stones by showing them set in jewelry. As he shows some examples, he explains how they carefully coordinate the colors of the metal with the enhanced diamond colors.

Mr. Karnavat tells us that public acceptance of colored diamonds has increased greatly since the early days, along with acceptance of technology in general. Treatments are the future, he says: Naturally colored diamonds aren’t getting any less expensive. Even more important, the supply is not there—especially of natural pinks—even if the customer has the money. @topic:10


Publish Year: 2007 Title: Summer 2007 G&G Book Reviews Abstract: “Gemmology, 3rd Ed.”
By Peter G. Read, 324 pp., illus., publ. by Elsevier Butterworth-Heinemann, Burlington, MA, 2005. US$39.95

“The Art of Enameling”
By Linda Darty, 176 pp., illus., publ. by Lark Books [www.larkbooks.com], Asheville, NC, 2006. US$17.95

“The Smale Collection: Beauty in Natural Crystals”
By Steve Smale, with photos by Jeff Scovil and Steve Smale, 204 pp., publ. by Lithographie LLC [www.lithographie.org], East Hampton, CT, 2006. US$50.00

“Horn: Its History and Its Uses”
By Adele Schaverien, 281 pp., illus., publ. by the author [www.hornhistoryuses.com.au], Wahroonga, NSW, Australia, 2006. US$60.00

“Laboratory Created Diamonds”
By Sharrie Woodring and Branko Deljanin, 39 pp., illus., publ. by European Gemological Laboratory-USA [www.eglusa.com], New York City, 2005 [no price information available]

“Gem Raw Materials and Their Occurrence in Serbia, 2nd ed.”
By Ilic ́ Miloje, 152 pp., illus., publ. by the Yugoslavian Gemological Association, Belgrade, 2006 [in Serbo-Croatian, with English summary, no price information available]

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


Publish Year: 1997 Title: Fall 1997 G&G Book Reviews Abstract: “Birthday Book of Diamonds”
Photos by Harold and Erica Van Pelt, 112 pp., illus., publ. by Harold & Erica Van Pelt, Los Angeles, CA, 1997. US$19.95

“Ruby & Sapphire”
By Richard W. Hughes, 511 pp., illus., publ. by RWH Publishing, Boulder, CO, 1997. US$98.00

“The National Gem Collection”
By Jeffrey Post, 144 pp., illus., publ. by Harry N. Abrams, Inc., New York, 1997. US$39.95

“Classical Loop-In-Loop Chains and their Derivatives”
By Jean Reist Stark and Josephine Reist Smith, 190 pp., illus., publ. by Chapman and Hall, New York, 1997. US$44.95

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


Publish Year: 1999 Title: The Separation of Natural from Synthetic Colorless Sapphire Abstract: Greater amounts of colorless sapphire—promoted primarily as diamond substitutes, but also as natural gemstones—have been seen in the gem market during the past decade. In the absence of inclusions or readily identifiable growth structures, natural colorless sapphires can be separated from their synthetic counterparts by their trace-element composition and short-wave ultraviolet (SWUV) transparency. Energy-dispersive X-ray fluorescence (EDXRF) analysis shows higher concentrations of trace elements (i.e., Fe, Ti, Ca, and Ga) in natural sapphires. These impurities cause a reduction in SWUV transparency that can be detected by UV-visible spectrophotometry (i.e., a total absorption in the UV region below 280–300 nm, which is not seen in their synthetic counterparts). This article describes a SWUV transparency tester that can rapidly identify parcels of colorless sapphires. @topic:3


Publish Year: 1995 Title: Fall 1995 G&G Book Reviews Abstract: “Standard Catalog of Gem Values, 2nd Edition”
By Anna M. Miller and John Sinlzankas, 271 pp., illus., publ. by Geoscience Press, Tucson, AZ, 1994. US$24.00

“Diamond Exploration into the 21st Century”
Edited by W.L. Griffin, 367pp., illus., publ. as Vol. 53 of the Journal of Geochemical Exploration, Elsevier Science, Amsterdam, 1995, US$250.

 “The New Alchemists: Breaking Through the Barriers of High Pressure”
By Robert Hazen, xvi, 287pp., illus., publ. by Smithsonian Press, Washington, DC, 1993. US$23.00

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


Publish Year: - Title: GIA Opens Laboratories in Israel and Japan Abstract: GIA opened two new diamond grading laboratories in 2012: one in Ramat Gan, Israel and one in Tokyo, Japan. These facilities, the eighth and ninth GIA global laboratories, are the latest steps in the Institute’s efforts to expand its ability to fulfill its mission to ensure the public trust in gems. By bringing industry-leading diamond grading services directly to important gem markets, GIA is making its services more easily accessible to laboratory clients.

“Offering GIA’s diamond grading standards and research-backed lab services to these important markets serves the public interest by supporting the Israeli and Japanese gem and jewelry industries,” said Tom Moses, GIA senior vice president for laboratory and research. “Our global network of laboratories enables GIA to remain at the forefront of gemological developments and provide the best possible service to our laboratory clients.”

Both facilities offer Diamond Dossier® and Diamond Grading Report services for colorless diamonds up to 2.99 cts. Additional services may be added in the future.

A reservation system for direct submission to the Israel facility, located in the diamond center of Tel Aviv, enables clients to schedule drop-off and pick-up appointments, eliminating the need to wait on-site to submit stones for grading services. They are also able to monitor the progress of their services online. If reservations are not available, clients can submit stones through GIA LabDirect consolidators who provide take-in services. Consolidators also take in diamonds larger than 2.99 carats, fancy color diamonds, colored gemstones and pearls.

The Tokyo lab also takes in colored stones and pearls for any other GIA services. At this time, those gems will be sent to another GIA global laboratory and returned to Tokyo for pick-up. GIA plans to expand the menu of services offered by its Tokyo facility in the coming months.

GIA began its global expansion in 2008, adding diamond grading services to its Bangkok laboratory and opening new laboratory facilities in Johannesburg, South Africa; Gaborone, Botswana; and Mumbai, India. In 2010, a lab opened in Hong Kong and a ninth facility is slated to open in Japan later this year.

All gemstones submitted to GIA anywhere in the world may be sent to any GIA laboratory, ensuring the equal, unbiased and neutral examination based on the rigorous and consistent standards that characterize all of GIA’s gem identification and grading services. @topic:6


Publish Year: - Title: My Life as a Colored Gem Liquidator Abstract: Bryan PavlikICA Director

	Interview with Bryan Pavlik, ICA Director
Mr. Pavlik started out buying and selling cut gems, then added gem cutting to his skill set with a stint in the famed cutting center of Idar-Oberstein. Eventually, he turned to liquidation of others’ excess and unused gem materials. Now, he travels the world to seek gems that, for one reason or another, haven’t sold, and matches those “unwanted” products with the right buyer.

Mr. Pavlik states that knowledge is essential to a successful liquidation business. He uses his cutting knowledge to help him determine if a stone can benefit from recutting—making it smaller, but also making it more marketable by eliminating distracting inclusions.

Market knowledge is also important. He tells of buying a quantity of fashioned tanzanite that a seller in Eastern Europe had been unable to sell for ten years. Mr. Pavlik bought the stones at a bargain price, recut them to improve their appearance, and resold them in the United States—where tanzanite was in demand—for a profit.

Turning to talk of the market, Mr. Pavlik explains that, while the US was once the biggest gem market, China, India, and Russia are expanding rapidly. Also, American and European markets are highly saturated at this point, so everyone in those markets is looking for the next level of stones: spectacular specimens, especially untreated stones of any kind.

He says this is where knowledge and disclosure come in: When you can explain to a customer the price difference between a treated and untreated stone, and even among different levels of treatment, the customer will understand what he can afford, making him more likely to buy.

He also says that brand names and certification are extremely important to today’s gem buyers, especially in China. All these factors will lead to an increased need for trained gemologists. The next decade, he says, will be the decade of the gemologist, but only the best ones with the most up-to-date skills.

Mr. Pavlik tells the interviewer that he is starting to limit his participation in gem shows to concentrate on other areas of his business. The next stage will be investment in high-tech identification equipment. True to his personal pursuit of knowledge, he will also learn how to use it to enhance his own business. @topic:11


Publish Year: - Title: New and Notable Finds from the GIA Lab: Winter 2023 Abstract: These new finds from the GIA lab include unusual colors and patterns in natural and laboratory-grown diamonds.

This 2.20 ct Fancy Deep brownish orange treated HPHT-grown diamond owes its distinctive appearance to multiple defect concentrations created within the various growth sectors. Photo by Diego Sanchez.
HPHT Diamond with Unique Color Zoning
The GIA laboratory in Carlsbad recently encountered a 2.20 carat laboratory-grown diamond that received a color grade of Fancy Deep brownish orange. This diamond was grown via the high-pressure, high-temperature (HPHT) method and received subsequent HPHT treatment. These treatment processes created crystal lattice defects that resulted in the interesting coloration of the stone as well as a dramatic pink square positioned just under the table facet. Learn what color the pink square changes into when viewed through the pavilion.

This 0.63 ct tapered baguette-cut diamond showed two major color zones. Photo by Adriana Robinson.
Natural Bicolor Diamond
This unusual 0.63 carat diamond exhibits two distinct color zones, one that was graded Fancy Dark orangy brown and one that was graded Fancy Dark brown greenish yellow by GIA. Bicolor diamonds are incredibly rare and are typically caused by a combination of different crystal lattice defects. What makes this diamond even rarer is that its brown greenish yellow color zone displays chameleon properties, meaning it temporarily changes color upon heating or when left in darkness for an extended period of time. Discover what geologic conditions created this one-of-a-kind diamond.

This 1.03 ct natural Fancy Dark brown diamond has uneven color zoning and abundant black inclusions. Photo by Mei Yan Lai.
Brown Diamond Containing Carbon Dioxide
The Carlsbad laboratory recently examined a 1.03 carat natural Fancy Dark brown diamond with uneven color zoning and numerous black hexagonal inclusions. Upon analysis, the diamond was determined to contain submicroscopic solid inclusions of carbon dioxide. This brown diamond containing carbon dioxide is one of the few of its kind that GIA has encountered. Explore what was trapped inside these carbon dioxide inclusions. @topic:10


Publish Year: 2002 Title: Summer 2002 G&G Book Reviews Abstract: “Diamond Ring Buying Guide, 6th Ed.”
By Renée Newman, 160 pp., illus., publ. by International Jewelry Publications, Los Angeles, CA, 2002. US$17.95

“Tiaras: Past and Present”
By Geoffrey Munn, 128 pp., illus., publ. by V&A Publications, London, 2002. US$22.50

“Diamond Stories: Enduring Change on 47th Street”
By Renee Rose Shield, 234 pp., illus., publ. by Cornell University Press, Ithaca, NY, 2002. US$29.95

“Perlen”
By Elisabeth Strack, 696 pp., illus., publ. by Rühle-Diebener-Verlag, Stuttgart, Germany, 2000 (in German). –C66.00

“Diamonds: In the Heart of the Earth, in the Heart of Stars, at the Heart of Power”
By Hubert Bari and Violaine Sautter, Eds., 351 pp., illus., publ. by Vilo International, Éditions Adam Biro, Paris, 2001. US$60.00

“The Jewels of Jean Schlumberger”
By Chantal Bizot, Marie-Noël De Gary, and Évelyne Possémé, translated by Alexandra Bonfante- Warren, 157 pp., illus., publ. by Harry N. Abrams, New York, 2001. US$39.95

“Glossary of Obsolete Mineral Names”
By Peter Bayliss, 235 pp., publ. by The Mineralogical Record Inc., Tucson, AZ, 2000. US$32.00

“Modern Gemmology, SSEF Tutorials 1 & 2”
By SSEF Swiss Gemmological Institute, www.ssef.ch, Basel, Switzerland, 2001. Available in PC or Mac format. US $150 each/$250 for both

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


Publish Year: 2024 Title: Exceptionally Rare Titanoholtite Abstract: Figure 1. A 0.85 ct oval modified brilliant titanoholtite. Although its bodycolor was dark orangy brown, a bluish haze was visible from certain angles due to light scattering off polish lines as well as internal colorless graining. Photo by Adriana Robinson.
A first-time submission of a rare dumortierite supergroup member was recently examined at the Carlsbad laboratory. A 0.85 ct titanoholtite (figure 1) was identified after extensive testing. The stone was submitted as dumortierite, but its physical properties and chemistry did not support this. The dark orangy brown stone had a hydrostatic specific gravity of 3.65 and a refractive index of 1.720–1.740 (birefringence of 0.020). These properties stand in contrast to dumortierite, which usually forms as an inclusion rather than a single crystal and typically has a blue to violet color, a specific gravity of 3.21 to 3.41, and a refractive index of 1.659 to 1.692 with a birefringence of 0.027.

Figure 2. Left: A clean and reflective surface-reaching fracture was seen under the table; field of view 3.57 mm. Right: Abundant transparent graining, scattered particles, and thin films were seen throughout the stone; field of view 2.34 mm. Photomicrographs by Britni LeCroy.
A look into the stone offered a vibrant scene composed of a reflective surface-reaching fracture breaking the crown (figure 2, left) and an abundance of transparent graining throughout with small flecks of reflective thin films and unidentified particles (figure 2, right). Microscopic observation revealed a strong resemblance to garnet, but the material’s doubly refractive nature was inconsistent with garnet. Raman spectroscopy results did not match any existing minerals within GIA’s reference databases, but they did show some general similarities with dumortierite. Finally, laser ablation–inductively coupled plasma–mass spectrometry was performed on the stone for a full quantitative chemical analysis. Given the general similarities with dumortierite, the chemical data was fit to a dumortierite supergroup formula of (Al0.35Ti0.41□0.24Fe0.02)Al6B(Si2.60Sb0.32)O17.67. The dominant component in this formula is titanoholtite, (Ti0.75□0.25)Al6BSi3O18, with minor dumortierite, Al7BSi3O18, and incorporation of significant antimony.
Titanoholtite is a recently discovered mineral within the holtite group and a member of the dumortierite supergroup. It was first published in 2013, when microscopic crystals were found in a Polish pegmatite (A. Pieczka et al., “The dumortierite supergroup. II. Three new minerals from the Szklary pegmatite, SW Poland: Nioboholtite, (Nb0.6□0.4)Al6BSi3O18, titanoholtite, (Ti0.75□0.25)Al6BSi3O18, and szklaryite, □Al6BAs3+3O15,” Mineralogical Magazine, Vol. 77, No. 6, 2013, pp. 2841–2856). This stone submitted to GIA appears to be the first macroscopic titanoholtite specimen ever reported in the literature. @topic:1


Publish Year: 2018 Title: Beryl and Glass Assemblage Imitating Emerald Abstract: Figure 1. Face-up, the assemblage displayed natural inclusions underneath the table. Large bubbles are also visible at the corners of the beryl core, a warning sign for the observant viewer. Photo by Jian Xin (Jae) Liao.

Assemblages of various materials have long been used as imitations of precious stones, with records dating back to Pliny the Elder’s Natural History (79 AD). Assembled stones commonly consist of two or more pieces of materials joined together in a parallel, layered fashion. Natural gem materials, such as spinel or garnet, are often used for the crown for the dual benefit of their durability and natural inclusions. The pavilion is typically composed of attractively colored, inexpensive materials such as glass or synthetic sapphire.

Figure 2. Left: All four glass sections of the pavilion assemblage are visible in reflected light. The small triangular segment is a protrusion from the opposite side. Photomicrograph by Tyler Smith; field of view 3.57 mm. Right: Metallic dendritic films supporting the natural provenance of the beryl core. Also visible are planar bubbles within the cement layer. Photomicrograph by Augusto Castillo; field of view 2.90 mm.

Figure 3. Face-up view under cross-polarized light displaying the inert reaction of the outer material and interference planes outlining the beryl core. Photomicrograph by Tyler Smith; field of view 14.52 mm.
A unique assembled 3.35 ct imitation emerald composed of five glass segments surrounding a rectangular beryl core (figure 1) was submitted to the New York lab. Microscopic observation revealed multiple nonparallel cement planes in the pavilion (figure 2, left). The crown was shown to be separated from the pavilion in a single piece, whereas the pavilion was composed of four asymmetrical exterior segments surrounding a sub-rectilinear pyramidal core. The core material contained inclusions typical of natural beryl, such as dark dendritic flakes (figure 2, right) and fingerprints. Large gas bubbles and internal chips were observed within the cement layers that accumulated at the beryl core’s corners. Standard gemological testing produced consistent refractive indices of 1.61 on both the crown and the four segments that made up the pavilion, a specific gravity of 2.99, and weak white fluorescence in the cement planes in long- and short-wave UV light. Under cross-polarized light, the outer material was singly refractive and displayed interference patterns along the interior join planes (figure 3). When immersed, the coloration was shown to be derived from the surrounding sections and joined by a colorless cement. This was further supported by ultraviolet/visible/near-infrared (UV-Vis-NIR) spectroscopy, which yielded a spectrum similar to manufactured green glass samples from our database. Raman microscopy of the crown and four pavilion segments produced amorphous spectra typical of glass. In addition to amorphous mounds, beryl peaks were detected in the core material, confirming prior suspicions.

Figure 4. Diagram showing the proposed model of the complex assembly of the composite stone. Final faceting is shown for simplicity. A: The first glass segment (green) is attached to the beryl core (gray). B: Both the core and the first segment are cut to make a flat surface for the second segment. C: The second segment (teal) is attached. D: The segments are again cut. E: The third segment (blue) is attached. F: The assemblage is shown rotated 180° for clarity. All current pieces are cut to create the surface for the final piece. G: The fourth and final segment (purple) is attached. H: Omitted for simplicity, the assembled pavilion would likely be polished flat to make room for the crown. Lastly, the crown (pink) is attached. The diagram was generated using Onshape CAD software.
Interestingly, the four glass segments in the pavilion assemblage are interlocked in a fashion that reveals a possible explanation of how the stone was manufactured. Based on visual observations, it appears the pavilion was constructed by a laborious multistep cut-and-glue process (figure 4). As a result of the iterant cutting, the first segment shares five sides that are parallel to the faces of the beryl core (four pyramidal faces and one basal). The number of faces parallel to the core decreases by one for each added glass segment. The asymmetry of the segments, parallel faces, and precise angles that match the sides of the core support the proposed model of ordered assembly.
The authors were not able to find any records of this type of assembled stone, and it was the first time one has been submitted to GIA’s New York or Carlsbad laboratories. Since all exposed surfaces were glass, it is assumed that the stone was fabricated relatively recently due to the sharp facet junctions and lack of wear. It is intriguing that an antiquated technique is updated in modern times, serving as a cautionary tale of the ingenuity counterfeiters employ. @topic:3


Publish Year: 2013 Title: Musgravite from Myanmar Abstract: Figure 1. These two musgravites (0.11 and 0.24 ct) are reportedly from Myanmar. Photo by Brad Payne.

              Two small, near-colorless stones reportedly from Myanmar (0.11 and 0.24 ct; figure 1) were recently loaned to GIA for examination by Brad Payne (The Gem Trader, Surprise, Arizona). Both samples had a refractive index of 1.718–1.723 and a specific gravity of 3.66 (calculated from optical measurements using a Sarin device, due to the small size of the samples). Both showed a very weak orange fluorescence to long-wave UV radiation and luminesced weak red to short-wave UV.

These properties are within the established ranges for musgravite and taaffeite, which have similar chemical composition and structure. Distinguishing between the two minerals requires Raman spectroscopy or X-ray diffraction. Conclusive identification of these samples as musgravite was accomplished by Raman spectroscopy (see L. Kiefert and K. Schmetzer, “Distinction of taaffeite and musgravite,” Journal of Gemmology, Vol. 26, No. 3, 1998, pp. 165–167). Even though several stones have been submitted to GIA’s laboratory over the years as musgravite, rarely have they been confirmed as such (see Summer 1997 Gem News, pp. 145–147; Spring 2001 Lab Notes, pp. 60–61).

Microscopic observation revealed a heavily roiled growth structure and small colorless needles and particulates scattered throughout. Also present were numerous black opaque hexagonal platelets, identified by Raman analysis as graphite (figure 2). Interestingly, the graphite platelets all appeared to be crystallographically aligned within the host musgravite.

	Figure 8. Hexagonal graphite platelets were the most conspicuous inclusion in the 0.24 ct musgravite. Photomicrograph by N. Renfro; field of view is 1.08 mm.
According to Mr. Payne’s supplier, Burmese “taaffeite” (which includes a small percentage of musgravite) comes from Chaunggyi, a few kilometers northwest of Mogok. Although production is quite limited, more musgravite may appear as miners become aware of this rare gem’s existence. Due to the overlap of physical properties between musgravite and taaffeite, stones suspected of being the rarer musgravite should be submitted to a qualified gemological laboratory for confirmation. @topic:1


Publish Year: 2013 Title: Yellow Synthetic Sapphire Colored by Trapped-Hole Mechanism Abstract: Figure 1. The UV-visible spectrum of this yellow sapphire shows broadband absorption features below ~500 nm, originating from trapped holes associated with Mg and Cr. The DiamondView image clearly displays curved bands (sub-parallel to the long direction of the stone under the table), indicating a synthetic origin. These curved bands are not seen with standard immersion, demonstrating the DiamondView’s effectiveness (the red color is due to the fluorescence of chromium). The stone’s CIE L*a*b* color coordinates are reproduced from the measured UV-visible spectrum.

              Natural sapphires with pale or lemon yellow color and no orange hue are traditionally associated with the chromophore Fe3+, which substitutes for aluminum in corundum. The New York laboratory recently received a 2.58 ct yellow emerald-cut stone (figure 1, inset), identified as sapphire by its RI and SG. But the desk-model spectroscope showed broadband absorption below ~500 nm without any of the Fe3+-related absorption features associated with yellow coloration (e.g., at 450 nm). Microscopic observation showed an exceptionally clean interior with only a small cluster of tiny particles that resembled gas bubbles from synthetic materials. The stone fluoresced medium orange to long-wave UV radiation and inert to short-wave UV.

The suspicious inclusion scene and the absence of diagnostic spectral features warranted additional testing. A standard immersion image failed to show any zoning or features. By contrast, a DiamondView image clearly revealed parallel curved bands characteristic of synthetic origin. Quantitative UV-visible spectra exhibited strong broadband absorptions in the blue and green regions and created a transmission window in the yellow spectral region (figure 1). Detailed chemical analysis via LA-ICP-MS was performed to identify chromophores and color origin. The elements Mg, Cr, and Ni were detected at trace levels (a few ppma). Naturally occurring elements such as Ga were not detected, further indicating synthetic origin. Trace Cr was confirmed both by red fluorescence and by laser photoluminescence spectra with 514 nm excitation, exhibiting a doublet at 692/694 nm and side bands.

A combination of trace-element analysis and UV-visible spectroscopy clearly indicated that the yellow color originated from the much more effective chromophore known as “trapped holes,” associated with the trace amount of Mg and Cr in this stone (J.L. Emmett et al., “Beryllium diffusion of ruby and sapphire, Summer 2003 G&G, pp. 84–134). By comparison, a sapphire colored by Fe3+ would only display a pale yellow coloration with a concentration above 500 ppma. This synthetic sapphire, however, showed no iron above the detection limit ( 1 ppma). The contribution of trace amounts of Ni is not well known.

Natural and synthetic sapphires colored by a trapped-hole mechanism often possess an orange or reddish orangy hue. This synthetic sapphire exhibited a yellow coloration much like those of samples colored by Fe3+. This example demonstrates that a clear understanding of chromophore contribution and the application of relevant advanced testing can reliably identify the cause of color as well as natural or synthetic origin. In this instance, the prominent curved growth supported the identification, but even without this feature a thorough understanding of the cause of color in sapphire can provide helpful identification clues. @topic:3


Publish Year: 2015 Title: Natural Faceted Red Rutile Abstract: Figure 1. The 4.40 ct natural red rutile on the left was compared with a 4.47 ct orange flame-fusion synthetic rutile. Photo by C.D. Mengason.

	The Carlsbad laboratory recently received a 4.40 ct dark red marquise brilliant (figure 1, left) for examination. Standard gemological testing revealed a refractive index that was over the limit of the RI liquid, as well as a hydrostatic specific gravity of 4.27. The specimen was inert to both long-wave and short-wave UV. Under reflected light, it showed a metallic luster. Raman testing identified the material as rutile. To distinguish it as natural or synthetic rutile, we compared it with a known flame-fusion orange synthetic rutile sample (figure 1, right).

Figure 2. In this natural red rutile, an octagonal blockage is capped at the end of the growth tube. Photomicrograph by Ziyin Sun; field of view 1.40 mm.

	Under magnification, the most distinctive internal characteristic of the dark red specimen was an octagonal blockage with a long growth tube extending to the surface (figure 2). Near the girdle, some unknown rectangular tabular inclusions were also observed, which were not identified by Raman spectroscopy (figure 3). Both internal features indicated the specimen was natural rutile. Straight and angular growth banding was also observed (figure 4). Raman spectroscopy for both the red sample and the orange synthetic revealed major peaks at 610, 446, and 242 cm–1 and minor peaks at 818, 707, and 319 cm–1, confirming their identity as rutile (see the RRUFF database at rruff.info).

Figure 3. Near the girdle, rectangular tabular inclusions are observed under fiber-optic illumination. Photomicrograph by Ziyin Sun; field of view 2.43 mm.

Figure 4. The natural rutile shows straight and angular growth banding. Photomicrograph by Ziyin Sun; field of view 4.92 mm.

	Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) revealed that the dark red rutile had a composition of 98.2% TiO2 and 1.5% Fe2O3 by weight, with traces of Mg, Al, Si, Ca, Sc, V, Cr, Cu, Zn, Zr, Nb, Cd, In, Sn, Sb, Hf, Ta, W, Pb, and U. The presence of Nb (176.81–296.93 ppmw), Ta (15.13–25.81 ppmw), Hf (0.15–0.40 ppmw), Zr (3.29–4.84 ppmw), Pb (0.01–0.56 ppmw), and U (0.07–0.27 ppmw) suggested a natural origin. The orange synthetic rutile contained 99.9% TiO2, plus traces of Mg, Si, Cr, Co, Cu, and Zn. Traces of iron (1.66 ppmw, 0.0238% Fe2O3 by weight) were also detected. Synthetic rutile boules created by the Verneuil process have an orange color with 0.04% Fe2O3 and a clear reddish color with 0.2% Fe2O3 (C.H. Moore, Jr. and R. Dahlstrom, “Synthetic rutile crystal and method for making same,” U.S. Patent 2792287). The red specimen’s lower chemical purity indicates natural origin.

	Visible spectra of both stones were taken. The red bodycolor of the natural rutile matched the transmission window between 650 and 700 nm in the red portion of the spectrum, which was likely caused by iron.

	Although rutile is a common inclusion in many minerals, the few crystals that are faceted usually weigh less than 1 ct. This faceted stone was very rare because of its large size. It was the first faceted natural rutile examined by GIA’s Carlsbad laboratory. @topic:3


Publish Year: 2017 Title: Remarkable Twinned Calcite Inclusion in Mogok Ruby Abstract: Viewed between crossed polarizers, an included calcite crystal within an unheated Burmese ruby displays dramatic twinning planes. Photomicrograph by E. Billie Hughes; field of view 3.90 mm.

The Mogok Stone Tract in Myanmar (formerly Burma) is one of the world’s most famous sources of ruby, which often forms there in a calcite-marble host. Calcite may occur as an inclusion inside the ruby, as in the example above. In this stone, the calcite is easy to spot between crossed polarizers, which reveal polysynthetic twinning planes that “crisscross” the crystal. While calcite is a common inclusion in ruby, this is the clearest example of calcite twinning this author has seen. Surrounding the calcite crystal is a dense, angular nest of exsolved rutile silk as short needles, a typical scene in rubies from this locality. @topic:3


Publish Year: 2022 Title: Gray “Spinel Sisters” Abstract: Figure 1. David Nassi’s 69.96 ct antique cushion-cut, loupe-clean gray spinel. Prized in the trade for its metallic-like sheen, gray spinel of this size, quality, and color is extremely rare. Photo by Robert Weldon.
At the AGTA show, 100% Natural Ltd. (New York) took center stage with some large, extremely rare gemstones spared of treatments of any kind. Two stones that caught the authors’ attention were a pair of exceptionally cut and nearly loupe-clean gray spinels weighing 69.96 ct (figure 1) and 11.78 ct (figure 2). There has been an increase in demand for gray spinel the past few years (Spring 2019 GNI, p. 130). Supply has remained relatively consistent, but larger, fine-quality stones are still quite rare.

Figure 2. The finest gray spinel is a pure neutral gray, without a blue or violet secondary color component, as exemplified by this 11.78 ct antique pear shape expertly cut by David Nassi. Photo by Robert Weldon.
Both of the gray spinels were cut from the same rough, weighing just over 220 ct and mined in Myanmar. Though famed for its rubies, Myanmar also produces equally fine red and pink spinel, as well as a range of other colors, including gray.
Master lapidarist and AGTA Spectrum Award winner David Nassi of 100% Natural Ltd. explained that gray spinel can appear lifeless and overly dark if cut poorly. His decision to create two “spinel sisters” from the same rough resulted from a fissure running through the large piece of rough (figure 3). The 11.78 ct stone provided more of a challenge, as the shape of the rough piece was a bit flat and asymmetrical when sawn from the larger stone. Inspired by a large Mozambique stone he cut many years ago, Nassi expertly fashioned this piece into an antique pear shape, perfectly complementing the larger 69.96 ct antique cushion cut (see video below).
Nassi and the authors agree that gray spinel has been an underappreciated treasure in the trade for a while now. Its presence at the AGTA show gives us hope that gray spinel is gaining the popularity it deserves.

Figure 3. The large rough gray spinel before (left) and after being sawn (right) because of a fissure in the rough. Not pictured is an additional small chipped-off piece weighing 3.32 ct, leaving open the possibility of a future third spinel sister. Photos courtesy of David Nassi.

	David Nassi Cutting Gray Spinel @topic:2


Publish Year: 2018 Title: Cat's-Eye Demantoid and Brown Andradite with Horsetail Inclusions Abstract: Figure 1. This 2.51 ct green demantoid with chatoyancy (left) contained well-aligned fibers of horsetail inclusions (right, field of view 1.10 mm). Photos by Shunsuke Nagai (left) and Taku Okada (right).
Two garnets were recently submitted to the Tokyo lab for identification. One was a green cabochon weighing 2.51 ct; the other was an orangy brown round brilliant weighing 2.47 ct. Both had a refractive index (RI) over the limits of the refractometer and a hydrostatic specific gravity (SG) of 3.84. To confirm the identification, we used Raman spectroscopy. Both stones matched the andradite garnet group from the reference database. The ideal chemical formula of andradite is Ca3Fe2Si3O12. The most important feature in both garnets was their horsetail inclusions. The presence of horsetail inclusions, which are thought to consist of chrysotile fibers branching out and radiating toward the surface from a small chromite nodule, has been regarded as diagnostic for natural demantoid.

The 2.51 ct stone was a rare cat’s-eye demantoid (figure 1). Demantoid garnet is by definition the green-colored andradite caused by chromium substitution. Chatoyancy is usually caused by closely spaced bands of long, thin parallel needles or fibers in the correct orientation, with a polished rounded surface such as a cabochon to reflect the light off the parallel inclusions. In this stone, the chatoyancy was due to the fibers of the horsetail inclusions. The radiating fibers were not parallel straight lines but parallel curves, so the “eye” was slightly curved.

Figure 2. This 2.47 ct orangy brown andradite (left) contained radiating horsetail inclusions regarded as exclusive to demantoid (right, field of view 1.60 mm). Photos by Shunsuke Nagai (left) and Taku Okada (right).
The 2.47 ct stone was an andradite garnet with classic horsetails (figure 2). The dominant bodycolor was brown. The gemological properties and chemistry were classified as andradite in the garnet solid solution, but it was poorer in calcium and richer in iron and silicon than the ideal andradite composition. The brownish cast was due to iron. On occasion we encounter stones with a strong yellow component that still have enough green to qualify as demantoid. However, this stone had no green in it and therefore was just andradite, not demantoid.

Consequently, the horsetail inclusions cannot be considered exclusively diagnostic for demantoid. They may also be found in non-green andradite. These two identifications—“cat’s-eye demantoid” and normal “andradite” in spite of horsetail inclusions—were issued for the first time in GIA’s colored stone report records. @topic:1


Publish Year: 2021 Title: Amphibole Mineral Inclusions in Mozambique Ruby Abstract: Figure 1. Densely distributed amphibole inclusions in ruby. Photomicrograph by Kazuko Saruwatari; field of view 9.40 mm.
Amphibole, a mineral supergroup with a diverse chemical composition of the general formula AB2C5T8O22W2, where A =  (vacancy), Na+, K+, Ca2+, Pb2+, Li+; B = Na+, Ca2+, Mn2+, Fe2+, Mg2+, Li+; C = Mg2+, Fe2+, Mn2+, Al3+, Fe3+, Mn3+, Cr3+, Ti4+, Li+; T = Si4+, Al3+, Ti4+, Be2+; and W = OH−, O2−, F−, Cl−, is a collectors’ item as a loose stone; its members are known as constituent minerals of nephrite (X. Feng et al., “Characterization of Mg and Fe contents in nephrite using Raman spectroscopy,” Summer 2017 G&G, pp. 204–212).

Figure 2. Rounded anhedral amphibole crystals. Photomicrograph by Masumi Saito; field of view 3.25 mm.
In addition, amphibole appears as crystal inclusions in both ruby and sapphire reported from Mozambique and Kashmir (e.g., Winter 2018 Lab Notes, pp. 435–436). Recently, the GIA lab in Tokyo received a Mozambique ruby densely included with rounded anhedral crystals (figures 1 and 2).

Figure 3. The Raman spectrum of the amphibole mineral inclusions (blue) and the reference spectrum of pargasite from the RRUFF database (R060072).
The Raman pattern of the surface-reaching crystals most closely matched the RRUFF reference spectrum (no. 060072) of the calcic amphibole pargasite (figure 3). The Raman peak at 669 cm–1 corresponded to the symmetric stretching vibration of T elements, which are tetrahedral ring structures composed mainly of the Si-Ob-Si linkage (Ob = bridging oxygen) and often used to fingerprint various amphibole species (N. Waeselmann et al., “Nondestructive determination of the amphibole crystal‐chemical formulae by Raman spectroscopy: One step closer,” Journal of Raman Spectroscopy, Vol. 51, No. 9, 2020, pp. 1530–1548).

Figure 4. The FTIR spectrum of the Mozambique ruby, indicating the amphibole-related peaks between 3600 and 3800 cm–1. The 3309 cm–1 peak is associated with corundum.
The FTIR pattern showed some peaks between 3600 and 3800 cm–1 in the principal OH-stretching region of octahedral metal components, which are C cations in the general formula of amphibole (figure 4). The FTIR pattern showed a peak at 3643 cm–1 in addition to peaks at 3671 and 3704 cm–1, suggesting the possibility that other elements such as Fe occupied those sites typical of pargasite in some portions (e.g., M.C. Day et al., “Gem amphiboles from Mogok, Myanmar: Crystal-structure refinement, infrared spectroscopy and short-range order–disorder in gem pargasite and fluoro-pargasite,” Mineralogical Magazine, Vol. 83, No. 3, 2019, pp. 361–371). The FTIR spectra of corundum between 2000 and 5000 cm–1 were very useful for the identification of mineral inclusions in corundum. This is the first known report of an FTIR pattern identifying amphibole mineral inclusions in corundum. @topic:1


Publish Year: 2017 Title: Flux-Grown Pink Synthetic Sapphire with Unusual Crystal Inclusions Abstract: Figure 1. This pink stone proved to be a flux-grown synthetic sapphire with unusual crystal inclusions. Photo by Robison McMurtry.

The Carlsbad laboratory recently received a saturated pink cushion mixed cut, mounted in a ring, that measured 14.02 × 10.35 × 6.24 mm (figure 1). Standard gemological testing yielded a refractive index of 1.760–1.768 and a weak ruby spectrum using a handheld spectroscope, properties consistent with pink sapphire. The stone displayed a strong orange fluorescence under long-wave UV and an odd chalky orangy yellow fluorescence under short-wave UV. While orange fluorescence is not unusual in pink sapphires, the intensity and the chalky yellow reaction were suspicious.

Microscopic examination revealed a single hexagonal, dark reflective platelet (figure 2); numerous transparent, colorless tabular to rounded doubly refractive crystals (figure 3) that showed interference colors under crossed polarizers; and a small fingerprint composed of elongated tubules. Observation in immersion showed some weak, straight orange and pink zoning. This inclusion scene could easily be mistaken for natural as the transparent crystals bore a certain resemblance to zircon, a common inclusion in natural sapphires and particularly pink sapphires from Madagascar. The dark reflective platelet, which was presumably platinum, and odd fluorescence prompted further investigation.

Figure 2. This dark reflective platinum platelet observed in the pink synthetic sapphire is a common inclusion in flux-grown synthetic corundum. Photo by Nathan Renfro; field of view 1.82 mm.

Figure 3. The abundance of transparent crystals and crystal clusters could easily be mistaken for a natural inclusion scene in a pink sapphire from Madagascar. Photo by Nathan Renfro; field of view 1.79 mm.
The synthetic nature of the sapphire was confirmed using laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS). High amounts of Pt were detected, which would support a flux synthetic growth process. Small amounts of Fe and Be were present; Ga, Ti, and V were not detected. This chemical profile also supports synthetic sapphire.

Transparent crystals of possible chrysoberyl (BeAl2O4) have been previously cited in flux-grown synthetic corundum (R.E. Kane, “The gemological properties of Chatham flux-grown synthetic orange sapphire and synthetic blue sapphire,” Fall 1982 G&G, pp. 140–153). In that case, Chatham stated that heavy concentrations of beryllium were added to the original aluminum oxide formula, which would explain the presence of those crystals. In our pink sapphire, none of the crystals reached the surface, so we were unable to identify them with Raman spectroscopy. Small amounts of beryllium were detected, so chrysoberyl could be a possibility in this case as well.

The presence of these natural-looking crystals combined with the general lack of other inclusions for a stone of this size, particularly diagnostic flux fingerprints, could make correct identification very difficult for gemologists without access to advanced instrumentation. This is one case where advanced testing in a well-equipped gemological laboratory was necessary to make a conclusive identification. @topic:3


Publish Year: 2020 Title: Rare Inclusion of Chabazite in a Precious Opal from Ethiopia Abstract: Chabazite inclusion in an Ethiopian opal. Photomicrograph by Aurélien Delaunay; field of view 1.42 mm.

An opal received for analysis at the Laboratoire Français de Gemmologie (LFG) in Paris was classified as a light opal, with a bodycolor that matched to neutral gray N8 on the Munsell scale. The play-of-color was divided into sections with well-defined outlines that fit together or were rounded off in the form of digits (B. Rondeau et al., “On the origin of digit patterns in gem opal,” Fall 2013 G&G, pp. 138–146). The drilled bead weighed 12.02 ct and measured 13.4 mm in diameter. It contained small black inclusions of pyrite but also a crystalline inclusion in the form of aggregated pseudocubes (see above). This inclusion was identified as chabazite via Raman analysis. The pseudocubes were in fact near-cubic rhombohedra.
While this mineral has already been documented in veins and opal nodules from Ethiopia, it is rarely seen in cut stones (B. Chauviré, “Genèse de silice supergène sur Terre et implications sur Mars,” PhD thesis, University of Nantes, 2015; N.D. Renfro and S.F. McClure, “Dyed purple hydrophane opal,” Winter 2011 G&G, pp. 260–270). Chabazite, CaAl2Si4O12·6H2O, is a member of the zeolite family. This mineral is formed in gaseous cavities of extrusive volcanic rocks, which is similar to how opals from Ethiopia form. This inclusion is also proof of the Ethiopian geographic origin of this gem, as it has not been described in opal from other localities. @topic:13


Publish Year: 2020 Title: Clarity-Enhanced Glass Imitating Emerald Abstract: Figure 1. Round gas bubbles in host material and flat gas bubbles within the break of fractures. Photomicrograph by Michaela Stephan; field of view 1.99 mm.

The Carlsbad lab received a transparent green octagonal step cut for identification. This stone visually resembled emerald due to its rich green color and large fractures. However, its single refractive index of 1.510 was not consistent with emerald’s double refractive index of 1.577 to 1.583.
Examination with a standard gemological microscope revealed no natural inclusions. Instead, it showed rounded gas bubbles in the body as well as flattened gas bubbles in surface-reaching fractures (figure 1). This stone has also been examined with FTIR and long-wave UV. When observed with long-wave UV, the fractures emitted a weak white fluorescence while the body of the stone showed a very weak blue fluorescence. The presence of these features was enough to conclude it had been clarity enhanced.

Figure 2. Shown are the infrared spectrum for the octagonal step cut (red line) and the typical reference spectrum for manufactured glass (dotted black line). The spectra have been offset for clarity.
Additionally, rounded gas bubbles separate from fractures, an RI of 1.51, and the sample’s FTIR spectrum (figure 2) were consistent with manufactured glass.
These gemological properties and observations identified the material as clarity-enhanced manufactured glass. Due to emerald’s high value, it is common for imitations to show up in the market. Items such as this demonstrate the need to always be cautious when purchasing gemstones. @topic:3


Publish Year: - Title: Ruby History and Lore Abstract: To commemorate the 50th anniversary of The Wizard of Oz, Harry Winston created real ruby slippers set with 4,600 rubies. - Courtesy Harry Winston

                      Red is the color of our most intense emotions—love and anger, passion and fury. It’s associated with objects of power and desire—like fast cars and red roses. Early cultures treasured rubies for their similarity to the redness of the blood that flowed through their veins, and believed that rubies held the power of life.

Ruby is one of the most historically significant colored stones. Rubies are mentioned four times in the Bible, in association with attributes like beauty and wisdom. In the ancient language of Sanskrit, ruby is called ratnaraj, or “king of precious stones.”

In the first century AD, the Roman scholar Pliny included rubies in his Natural History, describing their hardness and density. Ancient Hindus believed that those who offered fine rubies to the god Krishna were granted rebirth as emperors.

Hindus divided ruby into four castes, calling the true Oriental ruby a Brahmin. Someone in possession of a Brahmin was believed to have the advantage of perfect safety.

Ruby has accumulated a host of legends over the centuries. People in India believed that rubies enabled their owners to live in peace with their enemies. In Burma (a ruby source since at least 600 AD—now called Myanmar), warriors possessed rubies to make them invincible in battle. However, it wasn’t enough to just wear the rubies. They had to insert them into their flesh and make them part of their bodies.

The name ruby comes from the Latin word ruber, which means “red.” The glowing red of ruby suggested an inextinguishable flame burning in the stone, even shining through clothing and able to boil water.

Ruby has been called the most precious of the 12 stones created by God.

Ruby retained its importance with the birth of the western world and became one of the most sought-after gems of European royalty and the upper classes. Many medieval Europeans wore rubies to guarantee health, wealth, wisdom, and success in love.

Desire for ruby is just as great today as it always has been. As a symbol of passion, ruby makes an ideal romantic gift. Consumers are drawn to the lush color because it also signifies wealth and success. @topic:2


Publish Year: - Title: Jade History and Lore Abstract: This jadeite "Peiyao" (Chinese Fu dog) represent mythological creatures that guard and protect celestial palaces and entrances. - Gift of Sophie Leu

                      Jade has been cherished for thousands of years. It’s considered pure and enduring enough to inspire the wearer’s highest spiritual aspirations, yet sensuous and luxurious enough to satisfy down-to-earth cravings. Asian consumers have never lost their fascination for jade, and today, non-Asian buyers are drawn to jade as never before. All are attracted by its rich heritage as much as by its beauty, durability, and rarity.

Nephrite jade has its cultural roots in the smoke-dimmed caves and huts that sheltered prehistoric humans. In China, Europe, and elsewhere around the world, Stone Age workers shaped this toughest of minerals into weapons, tools, ornaments, and ritual objects. Their carvings invoked the powers of heaven and earth and mystic forces of life and death.

	Nephrite carvings have been popular in China for centuries. Photo courtesy China Gems.
The ancient relationship between this gemstone and humanity persisted into modern times among native societies in New Zealand and parts of North America. In China it evolved into an artistic tradition that has flourished for more than 3,000 years.

In Central America, the Mayans and the Aztecs prized jadeite jade. They used it for medicinal purposes as well as for jewelry, ornaments, and religious artifacts. The name jade comes from the Spanish expression piedra de ijada—literally “stone of the pain in the side.” Early Spanish explorers named it after they saw natives holding pieces of the stone to their sides to cure or relieve various aches and pains. Jadeite also symbolizes prosperity, success, and good luck.

It was in China—where the gem-carving tradition was already thousands of years old—that jadeite reached its peak as an important artistic medium. The first jadeite reached China from Burma (now known as Myanmar) in the late 1700s, and late eighteenth and early nineteenth century carvers created masterpieces that are still unsurpassed in concept, design, and technical execution.

The Chinese associate jade with clarity of mind and purity of spirit. Some of the ancient symbolic motifs still used in modern jade carvings (both nephrite and jadeite) include:

		Bat—happiness

		Butterfly—long life

		Dragon—power, prosperity, and goodness

		Peach—immortality

		Bi (flat circular disk with a hole in the center) - heaven

	This butterfly pin has wings carved from fine lavender jadeite. The butterfly symbolizes long life. - Courtesy Mason-Kay Fine Jade Jewelry

	The simple elegance of the disk-shaped Chinese eternity symbol, or bi, carries great spiritual significance for many Asians. - Courtesy Mason-Kay Fine Jade Jewelry @topic:9


Publish Year: 2013 Title: Rare Faceted Neptunite Abstract: Figure 1. This unusual 11.78 ct faceted neptunite appeared to be black but was actually a dark orangy red. Photo by Robison McMurtry.

              An 11.78 ct faceted “black” octagonal modified step-cut stone was recently presented to the Carlsbad laboratory for identification (figure 1). Standard gemological testing revealed an RI of 1.69–1.73 and a hydrostatic SG of 3.19. Microscopic examination with a fiber-optic light source showed the stone was actually a very dark orangy red. It was heavily included with fractures and platelets, as well as randomly oriented unidentified thin needles evenly distributed throughout the gem (figure 2). These tests suggested neptunite, an identity confirmed using Raman spectroscopy.

	Figure 2. The orangy red neptunite contained dense needles of unknown composition. Field of view: 1.72 mm. Photo by Nathan Renfro.

	Neptunite commonly occurs in association with, and as a guest inclusion in, the rare blue mineral benitoite (E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Vol. 1, ABC Edition, Zurich, 1986). Both minerals are Ti-bearing silicates. Benitoite may contain whitish inclusions of crossite (an amphibole) or natrolite (a zeolite), so it is possible that the thin needles in this neptunite are composed of one of these metamorphic minerals. The main source of neptunite is San Benito, California, where it is found along the walls of natrolite veins in blueschist (B. Laurs et al., “Benitoite from the New Idria District, San Benito County, California,” Fall 1997 G&G, pp. 166–187). The type locality for this material is the Narsarsuk pegmatite in Greenland (O.V. Petersen and O. Johnsen, “Mineral species first described from Greenland,” Canadian Mineralogist, Special Publication No. 8, 2005, pp. 76–77). Neptunite crystals have been found in sizes up to a few inches, but they are rarely faceted because of their brittle nature and relative softness (5–6 on the Mohs scale). The few crystals that are faceted usually weigh less than 1 ct, making this large specimen of particular interest. To the best of our knowledge, this is the first faceted neptunite identified by GIA. @topic:1


Publish Year: 2018 Title: Finds from the Secondary Market Abstract: Figure 1. Two of B&B's most spectacular finds on the secondary market were these two red beryls from Utah, which has been out of production for decades. Photos by Kevin Schumacher.
During the AGTA show, Dave Bindra of B&B Fine Gems (Los Angeles) showed us some noteworthy pieces from a gem collection he acquired last year and shared his thoughts about the state of the colored stone market.

Bindra noted that B&B is very active in searching the secondary markets for unique material. Last year, they came into a significant collection from a client. Several of the items had previously been in B&B’s stock, though the collection contains stones from all over the world. Among them are two incredible red beryls from Utah: a 3.01 ct emerald cut and a 4.08 ct round brilliant (figure 1) that is the world’s largest round red beryl. Bindra considers these two of the most important red beryls on the market. Red beryl from Utah has been well out of production in these sizes for decades.

Fabulous Finds from the Secondary Market
Dave Bindra of B&B Fine Gems shows some exemplary material from the secondary market.
Another highlight was a 61.92 ct Imperial topaz of unknown provenance and free of heat treatment (see figure 3 of the 2018 Tucson overview). The very rich sherry color in unheated Imperial topaz is extremely rare. That, plus the clarity and size, makes for an impressive stone of museum quality.

Also on display was a collection of 2–3 ct Kashmir sapphires, material that Bindra said customers are seeking, particularly in the Southeast Asian market. Kashmir sapphires have been out of production and even circulation for many years and are often found only at estate sales. Other remarkable stones from the collection included a 76.50 ct sphene with coloring reminiscent of a Christmas tree and a sugarloaf-cut 38.46 ct tanzanite (figure 2).

Figure 2. Also part of a collection purchased from a client was this 38.46 ct sugarloaf-cut tanzanite. Photo by Albert Salvato.
Bindra sees unprecedented demand for colored gemstones, particularly the high-end and unusual, making this an exciting time for those who deal in the rare and esoteric. There are a number of factors at play, including the influx of new consumers domestically and abroad, particularly in Southeast Asia, though the Chinese market is less active than in previous years. Record-breaking auction prices are also driving up the value of colored gems. Bindra cited commercial-quality Mozambique ruby as an example; the very finest specimens from that country still command top prices. The highest-quality Mozambique rubies exhibit a subtle fluorescence, giving them a glow reminiscent of Burmese material. B&B has sold some of the extraordinary pieces that were featured in previous G&G Tucson reports. Bindra believes that many Americans have generated new wealth and view colored gemstones in the same way they see other tangible and collectible assets, such as luxury cars and fine art. This has been a great boon to the market. As Bindra noted, “The time for color is now.” @topic:11


Publish Year: 2018 Title: Unheated and Unusual Colors Abstract: Figure 1. Madagascar Imports exhibited an array of small unheated stones, including 3.3 mm round brilliant lavender spinel from the Bekily region (left), and 2.5 mm round brilliant purple sapphire from Ilakaka (right). Photos by Jennifer Stone-Sundberg.
Margit Thorndal of Madagascar Imports, Ltd. (Laurel, Montana) was one of several AGTA vendors carrying small stones in today’s hottest colors. Thorndal showed two of her most popular stones from Madagascar: lavender spinel from the Bekily region and purple sapphire from Ilakaka (figure 1). Both materials are unheated and represent unique colors, particularly the lavender spinel.

Thorndal indicated that buyers appreciate the unheated and nontypical colors. Along with purple stones from Madagascar, she has been doing very well with pink and orange Malaya garnet from the Bekily region and bright yellow-green demantoid. The rough from Madagascar is all precision cut by hand into melee at a single facility in Bangkok. The finished stones are used by designers creating one-of-a-kind pieces, jewelers performing custom work, and manufacturers producing higher-end goods. She also showed a suite of 21 unheated Ilakaka sapphires totaling 22 carats that displayed attractive pastel hues (figure 2).

Figure 2. Suite of 21 unheated Ilakaka sapphires, approximately 1 ct each. Photo by Jennifer Stone-Sundberg.
Another item that has been doing very well for Madagascar Imports is unheated Montana sapphire, particularly in teal hues, a sentiment echoed at many other AGTA booths. There is strong demand for American gemstones, particularly untreated ones. @topic:2


Publish Year: 2019 Title: Faceted Chiolite Abstract: Figure 1. This 1.04 ct colorless octagonal cut was identified as chiolite. Photo by Diego Sanchez.

Recently, the GIA lab in Carlsbad received a colorless 1.04 ct gemstone of a material that was new to the lab (figure 1). The measured refractive index was 1.342–1.349 with a birefringence of 0.007 and an optic character of uniaxial negative. The specific gravity, measured hydrostatically, was 3.01. These properties were consistent with the mineral chiolite, which was confirmed by Raman spectroscopy (see figure 2 and http://rruff.info/R050412).

Figure 2. Raman spectroscopy confirmed the colorless stone’s identity as chiolite.
Chiolite is a very rare transparent to translucent colorless or snow-white mineral with a vitreous luster, perfect cleavage in one direction, and a white streak. It crystallizes in the tetragonal system and is composed of sodium and aluminum, with the formula Na5Al3F14 (the presence of these elements was confirmed with EDXRF). The principal source of gem-quality material is Ivigtut, Greenland, where it occurs in association with cryolite. Other gem-quality sources include Miass in the Ilmen Mountains region of Russia, where it is found in a cryolite pegmatite, and the Morefield pegmatite mine in Virginia (see AZoMining.com). The mineral was first discovered at Miass in 1846. The name is very similar to cryolite, a related mineral. Cryolite comes from Greek for “ice stone,” while chiolite means “snow stone.” Like their namesakes, they are sometimes found together, though chiolites are rarer.
This gem has a very low hardness (3.5–4 on the Mohs scale) and perfect cleavage. The stones are usually small and nondescript. Nevertheless, chiolite has joined the ranks of minerals cut by faceters who wish to try their hand at everything clean enough to cut, and a cut stone would make quite a specimen for a gem collection.
Chiolite occurs in some granite pegmatites and is associated with ralstonite, pachnolite, elpasolite, cryolite, thomsenolite, cryolithionite, fluorite, phenakite, and topaz (see mindat.org and rruff.info).
Chiolite is difficult to cut, extremely rare, and has little commercial appeal. It is solely a curiosity in the gem world. @topic:1


Publish Year: 2014 Title: Rare Faceted Wurtzite Abstract: Figure 1. This 3.97 ct faceted wurtzite has an adamantine luster and brownish red bodycolor.

              Recently the Carlsbad laboratory examined a 3.97 ct transparent brownish red pear-shaped modified brilliant for identification service (figure 1). Standard gemological testing revealed a refractive index that was over the limit of the RI liquid and a specific gravity (obtained hydrostatically) of 3.96. There was no fluorescence observed with exposure to long- and short-wave UV light. The stone also displayed an adamantine luster and a uniaxial optic figure when examined with polarized light. Microscopic examination with a fiber-optic light source showed fine needles and a large reflective decrepitation halo surrounding a negative crystal. Examination also revealed that the decrepitation halo was perpendicular to the optic-axis direction, suggesting the stone had basal cleavage (figure 2).

	Figure 2. A decrepitation halo surrounds a negative crystal in the faceted wurtzite. Photomicrograph by Nathan Renfro; field of view 2.15 mm.
Raman spectroscopy and X-ray powder diffraction conclusively identified the stone as wurtzite. EDXRF analysis detected zinc and sulfur, which further supported this identification.

Wurtzite, a polymorph of sphalerite, commonly occurs in hydrothermal vein deposits associated with barite and sphalerite. Facet-grade wurtzite has been reported to occur in Merelani, Tanzania (Winter 2013 GNI, p. 261). This is the first wurtzite examined by the GIA laboratory. @topic:1