Publication Year: - Title: Gemfields Bets on Gemstone Market’s Growth Abstract: Among the emeralds, rubies and other gems offered by Gemfields is this selection of Zambian emeralds from the Kagem mine. These emeralds have been cleaned, sorted and prepped for selling at auction in Lusaka. Photo by Robert Weldon/GIA, courtesy Gemfields.

                      In late November 2014, Gemfields unveiled a 40.23 ct ruby it had just unearthed from its Montepuez ruby deposit in Mozambique. The discovery made headlines, the kind usually reserved for large diamonds.

Indeed, when Gemfields’ CEO Ian Harebottle speaks about the colored gemstone industry, the word “potential” comes up in just about every sentence. He believes that colored gemstones’ share of luxury goods sales could increase greatly around the world—potentially rivaling diamonds—if jewelry manufacturers and retailers could count on regular supplies, stable pricing, consistent grading, and increased marketing support. He has set his company’s goals on doing just that.

This large 40.23 ct ruby was found in late 2014. Photo and courtesy Gemfields.
Gemfields faces a tall order in catching up to diamonds. Sales of gemstones remain a small fraction of diamond sales worldwide. In the US, they represent about 8% of jewelry store sales by value, according to the 2014 Jewelers of America’s Cost of Doing Business Survey. In China, that percentage is believed to be much higher, but with the vast majority consumed by the country’s passion for jade.

Gemfields, he believes, can be the change agent to lift gemstones to their rightful place in the market.

The company claims to be the world’s single largest known mining source of emeralds, with the production from its Kagem mine in Zambia, and is heading toward being able to make a similar claim for rubies, with its Montepuez mine in Mozambique. The company also operates the Kariba amethyst mine in southern Zambia.

	This giant emerald crystal from Zambia’s Kagem mine, named Nsofu, weighs in at 6100 ct.
	The smaller emeralds have a combined weight of 125 ct. Photo by Robert Weldon/GIA,
	courtesy Gemfields.
The company bases its clout on the fact that it is the largest of only three publicly traded gemstone mining operations in the world, an anomaly in an industry still dominated by very small firms with little capital and possibly a few larger firms at some localities around the world, with limited disclosures and transparency. It is also the only gemstone operation with both the resources and the willingness to spend a large portion of its revenues on marketing and advertising.

This atypically large-sized ruby crystal, approximately 9.00 ct, was found while GIA was visiting. However, a much larger 40 ct plus gem ruby has since been reported. Photo by Robert Weldon/GIA, courtesy Gemfields.
Last year, the company spent approximately $5 million – about one-third of its total advertising spend – on a marketing campaign that engaged actress Mila Kunis as brand ambassador for its emeralds. This year Mila is back, now sans makeup, to stress the “natural image” in a further $5 million campaign that extends to its ruby production.

In a break from most emerald and ruby producers, Gemfields sells its production openly through auctions, instead of through a private dealer network. This, according to Harebottle, both ensures that the company receives market-based, competitive prices for its rough, and gives a much wider range of leading global dealers access to supplies.

The company’s ambitious strategy consists of simultaneously tackling the following challenges: consistency in its product line, pricing, and grading. And it does this from the moment they mine the gemstones. “Consistent supply,” says Harebottle, “is where everything must start.”

Consistency has always been one of the most problematic challenges to the industry. Usually, when a deposit is discovered, small-scale miners flock to an area while the pickings are relatively easy to find, only to abandon it after the deposit dwindles, if quality of the gem material declines, or when the cost of inefficient extraction is more than the return—especially if a new, more lucrative area is discovered. The Winza ruby and sapphire deposit in Tanzania, which was discovered in 2007, offers an excellent example. For two years, gems flowed plentifully from the mine, but now, scarcely six years later, the primary deposits have been largely worked out, and very little fine material is easily accessible and reaching the market.

Additionally, many small mining operations avoid paying taxes and duties and then abandon the area after the easy shallow pickings have been removed, leaving the deeper-lying goods in the ground.

Gemfields’ high cost structure, supporting more than 1100 employees in three countries, and the capital costs of securing and operating a mine, limits the company’s ability to withhold goods when the market is rising, like many major gem dealers do, but they are still able to retain at least one year’s worth of emerald and ruby inventory at any given time for continuity of supply. Gemfields prefers to manage obtainable prices by driving demand, rather than trying to do so by holding back supply.  This age-old speculative practice invariably creates shortages that drive prices even higher, but stymie efforts by downstream retailers and dealers to create consistent jewelry lines.

Image of the Kagem mine prior to when Gemfields first started working it in 2008. Photo courtesy Gemfields.
But it all begins with the ground. When Gemfields took over the Kagem operation near Ndola, Zambia, in 2008, the first order of business was developing a systematic and efficient mining operation to achieve a consistent flow of material, says Robert Gessner, senior geologist at the mine. “Earlier mining methods had been haphazard, with numerous small pits scattered throughout.”

The Kagem mine in late 2014. Photo by Robert Weldon/GIA, courtesy Gemfields.

	Kafubu Location

	The Kagem emerald mine is in the Kafubu area, which is located in central Africa, at a critical
	intersection of the continent’s Pan-African belts. Map reproduced from John et al., 2004.

	Kagem Area

	The Kagem emerald mine (shaded green area) lies in the Kafubu emerald mining area.
	Reproduced courtesy Gemfields.
The Kagem mine is located about two hours from the copper mining town of Kitwe on a road that traverses through small villages and acacia trees almost to the country’s border with Democratic Republic of the Congo. The company invested $180 million to develop the deposit into a single, just over one kilometer-long pit that exposed all of the then-known emerald occurrences. Only a tiny fraction of the mass of rock and gravel removed from this pit is emerald-bearing ore—6000 tons out of one million tons each month—but the pay-dirt is rich, yielding between 250 and 300 carats of beryl and emerald per ton. About 8% of this production is gem quality, fairly high by most gem mining standards, with an additional 25% classified as “emerald” for use as beads. The remainder is called “beryl” for industrial and decorative uses.

From this rough, Gemfields established a detailed grading system to make its goods more appealing and understandable to the market. “It is the key to providing consistent supplies. Clients can know what they are buying, and count on goods being consistent at every sale. Confidence allows them to buy only what they need, in relatively large volumes, thereby allowing them to build out collections, improve their own economies of scale (in much the same way as many diamond sightholders are able to do) and further assist them in supporting these production runs with the associated marketing campaigns,” Harebottle says.

In the kilometer-long mining pit, workers perform a “quick sort,” washing the ore and then gathering the emerald crystals that have been blasted loose before the ore is sent to the washing plant. These are then placed through slots in padlocked and numbered boxes located nearby. The remaining ore is trucked out and sent to the crusher for further recovery.

(Left) As emeralds are first mined at Kagem, the initial search for emeralds continues. Workers wet the overburden to reveal tell-tale hints of green, while security guards keep a watchful eye from a distance. (Right) Any emeralds found, regardless of size or quality, are placed in holding boxes that are routinely picked up for transport to the emerald sorting house. Photos by Robert Weldon/GIA, courtesy Gemfields.
Gessner explained that a high percentage of the material by value—50% to 60%—is collected in the pit, with the remainder recovered later from the crushers, washing, and recovery operations.

Kagem’s senior geologist, Robert Gessner, spends some time at a “picking belt” at the washing plant, where pre-screened overburden from various active mining pits arrives, then is washed and sorted by size. Pickers are placed throughout the facility. Photo by Robert Weldon/GIA, courtesy Gemfields.
The key to accurate grading starts with rough processing (and sorting), explained Vijay Ameriya, sorting manager. The sorting house is a white brick building standing in the middle of the mining headquarters compound, surrounded by double rows of barbed wire fence. Inside the sorting house, workers thoroughly clean each rough stone. “Most of the matrix is removed,” he explains, “by gentle tumbling.”  Then, if necessary, by scraping and clipping the remainder of the matrix from the crystals. In the sorting room at Kagem, workers guided by small halogen lights remove the worthless material with the care of a surgical procedure. “This allows for a high level of value addition via accurate grading, sorting, weighing and parceling,” he says.

Clipping the crystals and “liberating” them from unwanted host minerals or matrix is time consuming, but experts do this with extreme care in an effort to not crack the underlying emerald crystals. Fiber-optic light helps reveal important emeralds under the matrix. Photo by Robert Weldon/GIA, courtesy Gemfields.
“This step is important because clients can see the color and they can trust that there won’t be any matrix included in the weights when we auction them.”

However, security demands that even the matrix must be accounted for, Ameriya explained, adding that the cleaned crystal is weighed along with the pieces of waste matrix to determine if the numbers tally with the pre-cleaned weight.

The production is broken down into four basic grades: “premium emerald,” “emerald,” “beryl 1,” and “beryl 2.” After that, the premium emerald and emerald are run through sizing sieves to sort by weight. Next, they are divided by color: green with a secondary hue of yellow and green with a secondary hue of blue.

	At the sorting house, a sorter examines the translucency, size, and color of an emerald
	crystal before adding it to an assortment. Photo by Robert Weldon/GIA, courtesy Gemfields.
They are sorted further by quality of color, tone, saturation, clarity, and shape. The graders, nearly all local workers, do the sorting in the main room of the plant, where, in the rear, there is a long table with 50 small piles of stones, representing each particular assortment of emerald grade, to be used as reference stones for classification of the company’s rough production.

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	Emerald Classification
Kagem’s production volumes have fluctuated greatly in the past eight years, though generally trending upward.

In its first year of operating Kagem (fiscal 2007), Gemfields reported that it mined 9.4 million carats of emerald and beryl.  Production increased slightly the following year, but leapt to 28 million carats for fiscal 2009, after Kagem upgraded its processing capacity. In 2010, production fell back to 17.4 million carats then fluctuated greatly: 35 million in 2011, 21 million in 2012, and 30 million in 2013.  The company reported it mined 20.2 million carats of emerald and beryl for fiscal 2014, down nearly 10 million carats from the previous year.  With 8% representing the finer material, such production would work out to about 1.6 million carats in fiscal 2014.

Revenues too, have been volatile. In 2011, the company reported sales of $40.9 million, jumping to $83.7 million the following year. However, in 2013 Gemfields reported a revenues of just $48.4 million, and a loss of $22.8 million. Included in the debit side, however, were costs associated with its acquisition of the Fabergé brand ($90 million in stock transfers). Also, the relocation of its primary emerald auction from Singapore to Lusaka delayed at least one sale until after the fiscal year had closed. In 2014, revenues soared 230.8% to $160 million as Montepuez ruby production came online, and the rescheduled fiscal 2013 emerald auctions swelled the total. The company, once again, turned a profit of over $8 million.

	MONTEPUEZ
Though rubies from Mozambique dominate today’s gemological discussions, their discovery is relatively recent. Indeed, they are not mentioned in 20th-century gemological literature, or in pre-1990 geologic studies scrutinizing this East African country’s gem potential.

Fine rubies are rarely plentiful anywhere, but they have been found in abundance in the Mozambique Belt, a geologic orogeny that stretches northward from Mozambique through Tanzania, Kenya, and Ethiopia. The Mozambique Belt yields many of East Africa’s gem materials, including tanzanite, tsavorite, a host of yellow, red, and color-change garnets, chrysoberyls, and, of course, rubies and sapphires that were discovered in Kenya and Tanzania in the mid-1900s.

Perhaps the greatest irony is that Mozambique, a former Portuguese colony now dusting itself off from decades of Communism and civil war following independence, will likely emerge as one of the most lucrative ruby sources in this century.

This view of the primary ruby deposit at Maninge Nice, in Mozambique, reveals the area that is being worked by Gemfields in the foreground, as well as the surrounding terrain and woodlands. Photo by Robert Weldon/GIA, courtesy Gemfields.
UK-based Gemfields, PLC, which has entered into an agreement with the Mozambique government regarding rubies from the Montepuez deposits, is keen to prove that the mining of rubies can be undertaken on a large-scale basis, categorized into definable and repeatable quality assortments, and sold through an orderly, systematic auction model. In so doing, the aim is to provide downstream buyers with a model of consistency and repeatability in a manner similar to what they have been able to achieve with their Zambian emeralds.

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	Searching for rubies in Mozambique

	Mozambique Map

Mozambique is located in southeastern Africa, with a long coastline that offers some of the most breathtaking beaches in the world. Its ruby mines are concentrated in the country’s northeastern corner. – Map adapted from Richard W. Hughes, 2009.

The Montepuez ruby operation, located in the mostly flat terrain of Miombo forests and occasional baobab trees about two hours west of the port city of Pemba, has been in operation for only two years. Makeshift villages of garimpeiros (artisanal diggers) have sprung up on the roads near the mine site because much of the area, including the primary mining area, remains unsecured.

Security at all Gemfields’ facilities requires visitors and employees to be searched before leaving the area. This security guard has a bird’s eye view of the ruby mining operations at Maninge Nice.  Nonetheless, illegal miners from surrounding areas still manage to penetrate into Gemfields’ claims, concealed in the thick undergrowth. Photo by Robert Weldon/GIA, courtesy Gemfields.
Montepuez consists of a primary deposit, Maninge Nice, and a secondary deposit called Mugloto, both situated in the same region.  The ore is so rich that those walking along its surface once exposed can easily pick up ruby and pink corundum. The ore washing and processing is done at the mine site, then trucked to the sorting house within the miners’ compound, located about 10 km  (6 miles) from the diggings. Like Kagem, all of the material is thoroughly clipped and cleaned from the waste material before sorting.

The washing plant at Maninge Nice, Montepuez, Mozambique. Photo by Robert Weldon/GIA, courtesy Gemfields.

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	Ruby Classification

These two ruby rough samples would be cut into fine-quality rubies from Mozambique. Photo by Robert Weldon/GIA, courtesy Gemfields.
The sorting house is a doubly-fenced facility located in the middle of the headquarters compound. The grading procedure is similar to Kagem’s but the grading is tailored to the different nature of corundum production. The basic grades are:

		Premium ruby: The highest qualities over 5 grams

		Ruby: The highest qualities below 5 grams and lower colors of about that weight

		Low ruby: These are segregated into three grades of color, size, and clarity. Much of this production has small fissures treated on-site with borax.

		Corundum

		Sapphire

		Small goods: -4.6 mm

About 60% of the production is corundum and pinkish to colorless sapphire, some of it treatable to a reasonable pink color. Low ruby represents about 20% to 25% of production. Ruby is about 10% to 12% and the premium grades constitute about 8%, says Phillippe Ressigeac, assistant product manager at the Montepuez sorting house.

The graders at Montepuez are helped by the fact that the source of most of the ruby and premium ruby is Mugloto, which produces material that is astonishingly homogenous in size and color, according to Gemfields.  Unlike the numerous emerald grades at Kagem, the top ruby from Mugloto falls into only four basic grades—A to D—depending on color and saturation. The A and B grades have colors resembling Burmese Mogok material, while C and D colors resemble the slightly darker Thai material.

Though cut from larger rough than the samples shown on the left, these 4.04 ct and 3.00 ct rubies from Mozambique represent some of the finer colors that can be achieved from similar rough. Photo by Robert Weldon/GIA, courtesy Evan Caplan, Los Angeles.
The material is further divided by size, shape, and clarity. The premium ruby is sub-divided into seven size classifications, from the largest, +22 millimeters, down to 2 mm.

Mugloto produces 2 to 3 carats per metric ton of ore. The material in the primary deposit, Maninge Nice, varies from “sapphire” (highly included, tabular, and fissured pinkish material) to the fine, cuttable qualities. At 162 carats per ton, there’s a lot of it. In fact, the deposit is so rich that visitors to the area literally walk over ground speckled with corundum—of all qualities.

Walking through the Maninge Nice ruby deposit at Montepuez, Mozambique, corundum (including some rubies) are visible along the surface. Photo by Robert Weldon/GIA, courtesy Gemfields.
Some of this low-quality material is similar to the pale, highly fissured stones found elsewhere near Montepuez that some dealers infuse with high-lead glass to create a “manufactured corundum product.”

Unfavorable news reports about such “glass-filled rubies” sold as natural without disclosure have cropped up in the US and other countries during the past several years, leading many gemstone dealers to say that such goods undermine confidence in all rubies. However, Harebottle sees no threat from unfavorable publicity spilling over to Gemfields’ finer production.

“First, I have no issue with treatments so long as they are clearly disclosed! Next, I believe consumers will work out what’s best for them, especially when supported by grading reports from recognized and respected laboratories.”

So, for him it’s about [informed consumer] choices. Top-quality ruby is an expensive stone, whereas treated goods are much more affordable and ubiquitous. “Should there not be scope enough in the market for various qualities and treatments of ruby, without one affecting the other and with each perfectly suiting an individual consumers finances and purchasing needs?” Harebottle asks.

A challenge confronting the trade is that, without disclosure at all levels, down to the final consumer, some of the fine material from Mozambique (left) could potentially be confused with the lowest-quality corundum that is glass filled. (right). Photo left by Robert Weldon/GIA, courtesy Evan Caplan; photo right by Robert Weldon/GIA.
Harebottle stresses that Montepuez is still in the exploration and expansion phase, so the grades and qualities could still fluctuate a great deal over the next few years. For example, for the quarter ended in June 2013, the company mined 1.1 million carats of all qualities. For the same period ended in June 2014, the total mined was only 200,000 carats, but the value was far higher, he says.

Indeed, the ore processing and washing equipment remains basic and relatively small, and the miners have been unearthing far more than this equipment can process. The company plans to at least double the capacity of the washing operation by the spring of 2015.

	SALES
Gemfields’ open auctions are a radical departure from traditional colored stone industry practice and indeed much closer to that which has been applied within the diamond industry for the past many years.

For as long as there has been a gemstone industry, most colored stone producers have sold privately through an established network of dealers, now mainly in South America and India for emerald and other gem materials, or in Thailand for corundum. As a result, prices have often been erratic, with huge variations on similar material.

But Gemfields believes auctions, supported by detailed grading, allow for more transparency and truer price discovery. Harebottle says this price discovery has resulted in a marked reduction in the overall volatility of the per carat/quality prices achieved at its annual emerald auctions which the company has run since 2011. “In the old days the variance between the lowest bids and the highest bids could have been as high as 10,000%.

We had a situation where many of the world’s experts were basically bidding on the same rough, and yet the prices they were offering could be quite varied at times. Now, though we still have some ‘cheeky’ customers [making low bids] on the odd occasion, the variance is far less and the prices offered are far more stable¾between 100 and 200% at most.” Harebottle attributes this to a natural settling-in of the buyers, but also because its customers are now able to better understand the run of production. According to Harebottle the process is as follows:

		All of Gemfields’ auctions operate on a straightforward closed bid/tender with reserve system.

		Before each auction, Gemfields works out its Minimum Reserve Prices (the lowest amount we are willing to accept for any given schedule), and this is placed in the sealed bid box before the auction starts.

		The auction attendees then have a number of days to evaluate the goods, after which they must place binding offers on each schedule. Gemfields doesn’t accept a single bid for the entire auction—all of the lots as a whole.

		These offers are written into bid-books, which are placed into the bid-box by the attendees. They can place more than one bid per schedule, but only the highest bid is considered.

		After the close of the auction, all of the bids are evaluated for each schedule, where the bids received are higher than the pre-set minimum reserve price (MRP). Each schedule goes to the highest bidder.

		After all of the bids have been evaluated, the attendees are notified which company won which schedule (just the company name and which schedule they won, not what they bid). Any schedule where the bids did not reach the reserve are also identified, but in this instance Gemfields does disclose what its expected MRP was so that the customers are at least able to have some idea as to the Company’s expectations going forward.

The auction process for both rubies and emeralds is similar, though they take place in different locations. Gemfields’ Kagem auctions of its mined emeralds are held at at regular sales in Lusaka, Zambia’s capital, following a request by the government for the auctions to be held on Zambian soil.

At first, the company had reservations about holding the auctions in Zambia—expressing fears that the key buyers may have been reluctant to attend. However, buyers have attended, and the most recent sale in November 2014, achieved a record per-carat price (nearly $66) for 530,000 carats, divided into 17 lots. More than 88% of the goods offered were sold. Harebottle says that this helps prove the international scope of the business.

Traded goods, or emeralds that are not mined by Gemfields themselves, are sold in Jaipur, India, where many of Gemfields’ clients do business, and where an established emerald cutting business has existed since Moghul times. Montepuez material is sold in Singapore.

Gemfields hopes to reduce the volatility of prices caused by the “here today, gone tomorrow” mentality that has pervaded the gem business. For gem dealers, this means the ability to replace their original stock with similar goods once it is sold. For jewelers and designers, such a model offers the ability to create repeatable jewelry lines from emerald and ruby, and most importantly it justifies the concerted marketing efforts required to bring colored gemstones back to the forefront of the discerning consumer’s minds.

Gemfields, in addition to its own production, buys material from local markets. Last year it acquired some $8.5 million worth of emeralds from open market sources, which it sold separately from its own production.

For Harebottle, segregation of this material is important, and a matter of accountability. “Even though we apply the well-recognized Know Your Customer protocols, we can’t know for sure what’s happened to these (outside) goods; how they were mined, or the extent to which the environments in which they were mined may have been treated, but we are able to guarantee that all taxes and royalties and are covered from the time they have reached our hands,” he says. In some cases, Gemfields believes it is buying back material poached from its own concession, or even filched at its sorting operations, despite intense security throughout its mine in Zambia, which is surrounded by a high chain link fence, security cameras, and guards at key spots throughout the mine checkpoints, and along the access roads.

Smile! You are about to be searched from head to toe by this security guard at Kagem. All employees, company officials, and visitors are subject to being searched at various locations throughout the two mining areas. Photo by Robert Weldon/GIA, courtesy Gemfields.
Montepuez, however, is spread over a much wider area and remains largely unsecured. The ten kilometer drive between the mine camp and the Montepuez diggings is through thick brush that provides ample cover for garimpeiros—illegal diggers—who constantly forage the concession in search of rubies.

Harebottle says he’s seen a lot of sad cases—garimpeiros who become ill or dehydrated working, as they do, without protection from the sun.

“We can understand their circumstances, but can’t condone the theft or destruction of the environment,” he says, noting that Gemfields and the government, by reserving certain areas for miners, try to achieve a balance that is fair to all.

Complicating matters, however, is that many garimpeiros are migrants from other areas, or other countries. “They carry these gemstones out of Mozambique illegally, paying no taxes or royalties, so neither the communities nor the country benefits,” he explains.

	MARKETING
Gemfields’ sales model was derived, with modifications, from De Beers’ single channel marketing formula—a formula Harebottle used at his previous affiliation with the tanzanite mine, TanzaniteOne.

Like De Beers, he and then CEO, Michael Nunn, wanted to manage supply and had the advantage of owning the largest concession in the world’s only tanzanite deposit. In tandem, they devised a sales strategy where they chose and vetted customers—or sightholders—who purchased their goods at regularly scheduled sales.  In addition, they devised a rough tanzanite-grading grid to help sightholders fully understand the qualities they were buying. Finally, much like De Beers did throughout much of the last century, TanzaniteOne established a marketing arm, the Tanzanite Foundation, to help increase demand and gradually lift prices.

“Further, we wanted some sort of pricing guide for tanzanite, and we wanted certification [or identification reports] for the gem to help provide increased transparency for the trade and consumers alike,” Harebottle says.

Ian Harebottle, CEO of Gemfields. Photo courtesy Gemfields.
“You would not believe the amount of pushback we received from the gem trade,” Harebottle recalls. “We were accused of attempting to commoditize the gem and were told that this kind of control would rob them of their ability to tell sell the gem to their customers on account of its ‘romance’.”

Harebottle notes that much was learned from those experiences, including the fact that it is not necessary to control a large portion of the supply. “We thought that a De Beers style market share was the key. But we have changed our view.

“The key driver of value today is the position a product holds in the mind of the consumer,” he stresses.  ”Much of this is achieved through advertising. Along with positioning our product at the forefront  the consumers mind, there has to be a clear understanding of what Gemfields stands for: ethics, transparency, legacy, provenance, excellence and creativity.”

	A Sugarloaf Green Emerald ring designed by Alexandra Mor, New York, features a large
	emerald from Kagem. Photo courtesy Alexandra Mor.
These are major concerns of the  “Millennial Generation” in many parts of the world, and one such millennial, Mila Kunis, wanted to see all aspects of the company’s operations for herself before allowing her name to be attached to its products, says Harebottle.  In that sense, Mila Kunis is like many millennials who want to be able to trace a product to its roots and understand what the product stands for—sustainability in addition to the traditional notions of beauty and rarity.

Referring to the 40.23 ct ruby, Harebottle says that Gemfields is committed to following the stone from the mine to its ultimate owner, after pre-forming, polishing and setting. (See Box A).

Box A: Paydirt and Corporate Responsibility

				Joseph Chilambwe, Senior Manager in charge of community relations for the Kagem mine in northern Zambia, extends his arm in a sweeping arc at the acacia tree forest before us. “Kagem has taken on the responsibility for this entire area, from our mine to the highway.”

				The Kagem mine is the largest emerald mine in Zambia, operated by Gemfields in partnership with the national government. The area, extending about 12 miles to the main highway running to the copper mining town of Ndola—about a three-hour drive—had been sparsely populated before emeralds were discovered there. Today, there are small plots where families have settled – families of illegal miners, farmers, or simply people looking for an income—scattered throughout the forested rolling hills around the mine area.

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					Building a Sustainable Community
				With Chilambwe at the wheel, we proceed down a reddish-brown dirt road that slices through the brush, on the way to a village called Kapila where Kagem has constructed a three classroom school. “This is the main road, which we maintain. But because the people are so scattered, we had to build eleven kilometers of additional roads so they can get to the classrooms,” he says.

				Turning into an abbreviated side road, he stops the car near several traditional houses that sit beside lush fields contrasting vividly against the surrounding dry scrub. “These families are part of the Kapila Green Farmers’ Cooperative that supplies our mine with fresh vegetables.”

				The fields are demarcated by well-tended irrigation ditches and yield cabbage, potatoes, onions, and several other staples. “In fact, the program is so successful that they’ve grown crops far in excess of the mine’s needs so we now have to find a way of getting them to market.”

				The school lies several miles past the farm, in an open field beside a formation of anthills that protrude from the landscape like monuments. The Kapila school, accommodating grades one to seven, for which Kagem provides all support, has three classrooms with teachers and aides also paid for by Kagem. Each classroom has three rows of wooden tables and benches that accommodate two or three students across, depending on the age group. The instruction consists of basic literacy (including English), mathematics, and home economics, though the instructors note proudly that at least one of their students has gone on to study at a university.  Technology and computer training are limited by the lack of electricity in the region and the difficulties that some of the students have traversing the distance to the classrooms each day.

				“This school is not yet recognized by the government,” says Chilambwe, “so we still support it fully until then.” In Chapula, another five kilometers down the road, Kagem built a larger school with seven classroom blocks that serves children up to 10th grade, notes Chilambwe.

				Nearby is the Nkana clinic, designed to service basic medical needs for both Kapila and Chapula. We arrived too late to talk with the staff but Chilambwe told us it employs a nurse to handle routine care and has access to an ambulance for more serious cases.

				Montepuez in Northern Mozambique is also located in a relatively remote area, the closest major city being the port of Pemba, approximately a three-hour drive to the southwest. Our time at Montepuez was too limited to visit the surrounding areas but the mine’s project manager, Sanjay Kumar, explained that the company has developed drinking water wells for two local villages, Namanhumbir and Nacoja, both about ten miles from the mine site. It has also renovated the school and village market at Namanhumbir and contributed to renovating schools in several other villages.

				“There are a lot of other things that we do for the people in the area,” Krumar says. “There are thousands of illegal miners in our concession and sometimes we have to find medical care for those who have fallen from dehydration.”

				Gemfields had some major fence-mending to accomplish with the local community after it assumed control of the concession in 2012. Before then, there were numerous instances where guards at the mine shot at, and occasionally killed, illegal miners (garimpeiros). This long had been a problem in the area, according to local press reports. In one instance, shortly before Gemfields’ arrival, guards fired on 300 miners, killing one and wounding two others.

				Additionally, Gemfields announced at its December 2014 auction of Montepuez rubies that it has begun supporting anti-rhino poaching efforts by helping to fund the aerial surveillance of game preserves along the 300 mile-long border between Mozambique and South Africa. The African rhinos are highly endangered and Gemfields named a 40.23 ct. ruby it discovered in November 2014, the Rhino Ruby, to raise more awareness of the issue.

Gemfields acquired some glamor of its own in 2013, when it bought the venerable Fabergé jewelry brand, which had been revived six years earlier. Harebottle says that the brand will provide the perfect platform for its gemstones and Gemfields desire to reinvigorate the jewelry sector as a whole. The brand operates about a dozen boutiques around the world and Fabergé designers have integrated Kagem emeralds and Montepuez rubies into its jewelry creations.

Can Gemfields accomplish all it has set out to do?

Doug Hucker, executive director of the American Gem Trade Association, likes the company’s emphasis on marketing and responsible mining practices. He also believes that steady supplies can be a great benefit, but doubts that Gemfields could bring order to a traditionally disordered trade.

“They want to establish consistent pricing. Perhaps they can for their product: Zambian emeralds. But Colombian emeralds are different goods,” he explains. “So it’s not likely that Gemfields’ prices will completely translate.”

Additionally, he says that “getting these (gem producers) to come together is like herding cats. Second, it takes immense resources and high market share to influence supplies and prices across-the-board. It is not certain Gemfields has the market share to do this.”

Harebottle realizes that the gemstone industry remains skeptical about Gemfields’ market initiatives, especially pricing. Many are particularly worried that detailed, consistent grading leads to commoditization. He doesn’t dispute that. Indeed, he believes that a Rapaport type price list would potentially be a boon to the industry in time as it supports increased consumer confidence, especially for stones over two carats, but he also understand many of the inherent challenges.

“Some short-term profits may be lost, but the industry will more than make up for that through increased sales because people will know the value of what they have purchased instead of dealing with (the current state of) huge variations in price and uncertainty.”

He admits that this is not a popular view among most colored stone dealers and producers who he believes are still stuck in the past, but that colored stone demand has come a long way in recent years, though from a low base. “Increasing transparency and increasing consistency of prices and supplies will result in more demand for colored gems across the board. I have no doubt about that and that it will be good for everyone when it happens.” @chapter:38


Publication Year: 1993 Title: Heat Treating the Sapphires of Rock Creek, Montana Abstract: Renewed interest in large-scale commercial mining of Montana sapphires motivated a detailed study of the heat treatment of sapphire from the Rock Creek deposit. During the course of this systematic study, over 75,000 stones were processed. It was found that approximately 65%-70% of the pale blue, pale green and near-colorless sapphire could be converted to well-saturated blue and yellow colors. Some improvement in clarity was noted as well. Yellow hues were easily developed by heating in oxidizing atmospheres and were relatively insensitive to time and temperature. Blue hues were developed by processing in reducing atmospheres. The relatively high iron content of Rock Creek material restricts the range of reducing conditions that can be used to achieve optimal coloration because of hercynite precipitation in the sapphire. @chapter:9


Publication Year: 2020 Title: Marble Imitation of Jadeite Rough Abstract: Figure 1. This 30 kg stone was submitted as a piece of jadeite rough. A narrow window (in the red circle) opened on the surface of the rough reveals a green material underneath the skin. Photo by Huang Jing.
In recent decades, jadeite prices have risen dramatically. Driven by profit, a variety of imitations are found in the jadeite jewelry market. Meanwhile, imitations such as quartzite are fixtures in the rough jadeite market. Recently, our research group received for testing a 30 kg stone that resembled jadeite rough and was submitted as such. The stone had a yellow weathered skin with a grainy texture, similar to jadeite. There was a narrow “window” (figure 1) that showed the green color of the material underneath the skin. For identification purposes, the authors exposed another area on the surface of the rough and then ground it for testing.
Due to the weight, some standard gemological testing methods could not be used, such as measurement of refractive index and specific gravity. Therefore, the sample was studied by visual and 10× loupe observation, hardness testing, chemical reagent detection, and infrared spectroscopy.

Figure 1. This 30 kg stone was submitted as a piece of jadeite rough. A narrow window (in the red circle) opened on the surface of the rough reveals a green material underneath the skin. Photo by Huang Jing.
Scratch testing revealed a Mohs hardness between 2 and 5, lower than jadeite’s hardness of 6–7. The surface was yellow, just like the weathered skin of jadeite rough, and the narrow window in figure 1 revealed green color below the skin. Scrubbing the window with alcohol removed the green color, indicating that the window had been dyed. To test the material, diluted hydrochloric acid was dropped on the newly exposed portion in figure 2. The acid foamed continuously, showing that the sample contained carbonate (Z. Hanli et al., “Study on acid polishing of carbonate white jade,” Journal of Gems and Gemmology, Vol. 5, No. 4, 2003, pp. 24–27). The acid testing combined with visible observations and hardness testing identified the sample as marble. The jadeite granular structure came from the marble’s cleavage planes.
Testing of the exposed part by infrared spectrometry revealed 1525, 1432, 1080, 883, 670, 553, and 483 cm–1 absorbance peaks, characteristic of serpentinized marble.
The serpentinized marble’s yellow weathered skin and grainy texture could have easily been mistaken for jadeite rough. This serves as an alert to the industry to be careful even when examining rough, as imitations are showing up. @chapter:37


Publication Year: 2012 Title: Natural Pearls from Australian Pinctada Maxima Abstract: The fascinating and colorful history of natural pearling in Australian waters is presented, from the early six-man luggers to the large ships in modern fleets where pearl culture has been the focus for the past several decades. For the scientific investigation of this paper, the authors retrieved natural pearls from wild Pinctada maxima in Australian waters and recorded the various properties that might help to differentiate between natural pearls from this mollusk and those that are accidental by-products of the culturing process. Three distinct categories of host Pinctada maxima shells and mantle pearls were collected and examined by the authors: (1) from wild shell prior to any pearl culturing operation, (2) from wild shell after pearl culturing and approximately two years on the farm, and (3) from hatchery-reared shell prior to pearl culturing. Data were collected from microscopy, X-rays of internal structures, using real-time microradiography and X-ray computed microtomography, various forms of spectroscopy, and LA-ICP-MS chemical analysis. The results showed that microradiographic structures previously considered indicative of an accidentally cultured P. maxima pearl may not be conclusive, and that such criteria should only be applied with the utmost caution by an experienced technician. @chapter:14


Publication Year: - Title: Distance Education is an Avenue to Embark on a New Career Abstract: What can you do to enhance your chances of staying gainfully employed – either at your current job or a new one? Simply increase your marketability by broadening your knowledge and skills with additional training.

One of the ways you can gain additional training is through continuing education, which can include attending college classes or enrolling in distance education. The latter has become one of the most popular because it allows you to study in your spare time, at your own pace, and in the convenience of your home or office. Distance education is especially suited for busy people who wish to gain additional skills without giving up their current jobs. This “learn-while-you-earn” opportunity distance education offers is popular. For those out of work, enrolling in a distance education course can be a quick and convenient way to train for a new career. It’s also an ideal way for those employed to enhance their skills and become a more valuable employee.

The Wellspring, an online community of distance educators, says the number of distance education programs offered by community colleges and universities across the United States and Canada is “increasing at a phenomenal rate.”

Almost any field of interest imaginable is available via distance education, including architecture, engineering, computer programming and jewelry – to name a few. Each field also contains specialties. For example, positions in the gem and jewelry industry can range from identifying and grading gemstones to designing or manufacturing the latest jewelry, and from selling jewelry to managing a retail jewelry store.

Each of these requires specialized training. GIA (Gemological Institute of America) offers many distance education programs – along with its On Campus programs. The Institute is recognized as a leading educational institution for the gem and jewelry industry. GIA’s Carlsbad campus joined only 17 schools in receiving the Accrediting Commission of Career Schools and Colleges (ACCSC) School of Excellence award for 2011-2012. To qualify for the award, the majority of a school’s programs must meet or exceed a graduation rate of 92% for programs three months or less in length, and 82% for programs from 4-to-6 months in length, and demonstrate an average employment rate of 82%.

“Training for a position in retail jewelry sales via distance education is one of the easiest ways to start a career in the gem and jewelry industry,” says Bev Hori, GIA vice president of Education and chief learning officer. “And opportunities in this field are expected to be plentiful.  A retail jewelry sales position can also lead to a substantial income for top sales professionals, and commissions can add even more to the income.” @chapter:36


Publication Year: - Title: Emeralds: Colombia’s Buried Treasure Abstract: A miner holds an emerald in the mine office in the village of Coscuez, Colombia. Photo by Eric Welch/GIA

No one can be more familiar with or cherish the magnificent emerald more than the miner himself. At the end of a long day of labor, the miner illuminates and holds firmly the prize of the day.

Miners in Colombia have unearthed the world’s most sought after and valuable of the green gemstones. The characteristic rich greens unique to Colombian emerald are historically appreciated more than any other locality on Earth.

To chart a “treasure map” of Colombia’s finest gemstones, start in the capital of Bogota. From there, draw a line due north for approximately 200 km (124 miles), into the Cordillera mountains of the Andes. Then, strike an arc 90° due east.

Buried within this quadrant, you will find some of the finest emeralds in the world, as verdant as the rainforest, mountains and valleys where they have been buried for millennia − and sought after for centuries. The renowned colored gemstone localities of Muzo, Coscuez and La Pita lie to the north, and Chivor to the east.

Lake Guatavita, 120 km (75 miles) west of Chivor, is steeped in legend and lore, garnished with flecks of truth. The raft of El Dorado (The Golden Man) from the Muisca period depicts a ceremony on the sacred lake. It is said that the legendary El Dorado would be covered in gold dust daily and bathed in the waters of Lake Guatavita.

Spanish and English Conquistadors in the 16th and 17th centuries avidly sought the ceremonial gold dust and precious jewels thrown into the lake.

View Gallery

The pre-Columbian emerald and gold jewelry seen in the gallery above could very well be examples of the types of emerald jewelry used in these rituals and spurred European Conquistadors in their search for the gold and jewels of El Dorado.

La Pita, another well-known emerald mining locality, is home to Itoco, a mythical mountain peak named for the son of queen Fura and her husband Tena. Legend says that tears shed in the tragic love story of Fura and Tena turned into beautiful green stones that lay buried underground.

Emeralds are not the only treasure buried in the verdant land of Colombia. Rubies, sapphires and diamonds are also found there, though more rarely. Feast your eyes on the rainbow of colors of gemstone treasures from deep within the land of Colombia—red rubies, blue sapphires and yellow diamond. @chapter:25


Publication Year: 2016 Title: Unusual Purple Inclusion in Emerald Abstract: Figure 1. This 7.11 ct emerald contains a large purple inclusion visible under the table. Photo by C.D. Mengason.

	Depending on geographic locality, inclusions in emerald are typically similar from one stone to the next. We expect to see classic jagged three-phase inclusions in Colombian emeralds or blocky multiphase inclusions and phlogopite in Zambian emeralds, so it is always interesting for the gemologist to observe something out of the ordinary. The Carlsbad laboratory recently examined a 7.11 ct oval mixed-cut emerald (figure 1), identified by standard gemological testing. Microscopic examination revealed jagged to irregular multiphase inclusions, planes of reflective thin films, clarity-enhanced fractures, and—surprisingly—a fairly large purple inclusion with a subhedral form. Upon closer examination, distinct purple and near-colorless banding was visible (figure 2), and the inclusion proved to be singly refractive when viewed between crossed polarizers. The inclusion was too deep within the stone to confirm its identity with Raman spectroscopy, but its appearance and optic character pointed to fluorite. Based on these characteristics, another possible identity could be halite, but this inclusion strongly resembled a color-banded fluorite inclusion previously reported in emerald by GIA’s laboratory in 1969. In that example, the surface-reaching inclusion was identified by scraping a sample and analyzing it with X-ray diffraction (R.T. Liddicoat, “Developments and highlights at the Gem Trade Lab in Los Angeles,” Summer 1969 G&G, p. 63).

Figure 2. With microscopic examination, clear purple banding is apparent within this fluorite inclusion. Photomicrograph by Jonathan Muyal; field of view 2.34 mm.

	Fluorite inclusions in emerald have been cited from various localities, as a product of pegmatitic/hydrothermal involvement in formation (E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Vol. 3, Opinio Verlag, Basel, Switzerland, 2008, pp. 354–406; D. Schwarz et al., “Emerald and green beryl from Central Nigeria,” The Journal of Gemmology, Vol. 25, No. 2, 1996, pp. 117–141). These inclusions are usually described as colorless octahedra, although sometimes they are seen as cubes or rounded shapes. Purple banded fluorite is an unusual inclusion in emerald, making this an interesting and unexpected addition to an otherwise typical inclusion scene. @chapter:10


Publication Year: 2016 Title: Quarterly Crystal:Growth Features on Titanite Abstract: Figure 1. This beautifully formed 17.04 mm titanite
crystal from Russia owes its green color to the presence of vanadium. Photo by Kevin Schumacher.

	The micro-world of gems and minerals involves not only solid and fluid inclusions, but also significant surface features. If a gem crystal is fashioned into a gemstone by a lapidary artist, most of the surface features of any significance are removed during the process. So when we encounter a beautiful gem crystal, we always take the opportunity to examine the natural surfaces for any interesting evidence of growth or dissolution.

	In that regard, we recently studied a beautifully formed titanite crystal (figure 1) from the Ural Mountains in Russia that measured 17.04 × 15.27 × 0.94 mm and weighed 2.35 ct. EDXRF analysis confirmed that its bright green color resulted from the presence of vanadium. As shown in figure 2, examination of the surface using Nomarski differential interference contrast microscopy revealed an abundance of growth features, some with rather dramatic architecture. These were the features targeted for photomicrography.

	Figure 2. Some of the growth features observed on the surface of the titanite crystal were reminiscent of jagged mountain peaks. Photomicrograph by Nathan Renfro; field of view 0.72 mm. @chapter:13


Publication Year: 2023 Title: An Unusual Metallic Core in a Natural Pinctada radiata Pearl from Kuwait Abstract: Figure 1. The cream-colored pearl weighing 0.23 ct and measuring 3.20 × 3.12 mm, shown against the anterior of a Pinctada radiata mollusk. Photo by Nuttapol Kitdee.
The pearl (oyster) beds, or heirat in Arabic, around the State of Kuwait in the Persian (Arabian) Gulf have been known throughout history for producing some of the finest natural pearls. GIA’s Bangkok laboratory recently examined a quantity of these pearls obtained from a Kuwaiti pearl diver. The trusted diver said they were fished from wild Pinctada radiata mollusks at depths of 6 to 15 meters from one of the main pearl beds in the waters of Kuwait. The parcel consisted of various shapes and colors ranging from white to light yellow, with a few colored pearls as well.
The samples showed a variety of internal structures, but one round cream-colored pearl in particular, weighing 0.23 ct and measuring 3.20 × 3.12 mm (figure 1), revealed an interesting structure using real-time microradiography (RTX) and X-ray computed microtomography (μ-CT) analyses. When viewed under 40× magnification, the pearl’s smooth and high-luster surface exhibited typical nacreous overlapping aragonite platelets.

Figure 2. Top: RTX images revealing the entire volume of the pearl’s internal structure in two different directions. Bottom: Slightly enlarged μ-CT scans showing the radiopacity of the core more clearly. The darker areas are organic-rich.

Figure 3. RTX image of a bead cultured pearl reference sample with a metal post in the drill hole. The metal appears radiopaque and matches the appearance of the core feature in the pearl examined in the present study.

Figure 4. The 3D models generated using μ-CT scans show the blue area as the metallic core, while the surrounding area represents the pearl’s growth structure.

	3D Model of a Pinctada radiata Pearl with a Metallic Core

RTX imaging revealed a very unusual small ovalish radiopaque white core located in the pearl’s center. The radiopaque core stood out in contrast to the rest of the pearl’s structure (figure 2), indicating that the feature was composed of a material containing elements with higher atomic numbers on the periodic table. The appearance of the core was typical of that seen for metals when examined by X-rays, such as the metal post within the drill hole of the pearl in figure 3. The core measured approximately 0.19 × 0.15 × 0.13 mm and was surrounded by fine concentric rings with a small area of associated radiolucent organic-rich material. The small organic-rich area extending toward the outer growth layers appeared darker gray in the RTX and μ-CT images. Although the metallic core created doubts about the pearl’s origin, the associated concentric ring structure surrounding it was more indicative of natural origin. The μ-CT scan images were also rendered using specialized software (“New 3-D software expands GIA’s pearl identification capabilities,” GIA Research News, May 13, 2016) to create a three-dimensional image that made it easier to visualize the form of the central metal core (figure 4; see video of the 3D model).
Energy-dispersive X-ray fluorescence spectrometry revealed no manganese and a strontium level of 1400 ppm, which is characteristic of a saltwater environment. Raman analysis using 514 nm laser excitation was also carried out on the pearl’s surface and showed a doublet at 702 and 705 cm–1 as well as a peak at 1085 cm–1 indicative of aragonite. Weak polyenic pigment peaks associated with the pearl’s cream coloration were also observed at around 1135 and 1530 cm–1. Ultraviolet/visible reflectance spectra showed features at around 410, 435, and 460 nm and an additional band at 495 nm, in keeping with observations previously recorded for Pinctada radiata pearls (A. Al-Alawi et al., “Saltwater cultured pearls from Pinctada radiata in Abu Dhabi (United Arab Emirates),” Journal of Gemmology, Vol. 37, No. 2, 2020, pp. 164–179).
Although GIA was not permitted to cut the pearl in half or grind the surface down to reach the metal, we believe the feature may be a metal oxide similar to one previously documented (M.S. Krzemnicki, “Pearl with a strange metal core,” SSEF Facette, No. 24, 2018, p. 27). How this apparent metal found its way inside the mollusk is still a mystery. Since the diver found the pearl with other natural pearls that GIA also examined and confirmed, and it came from an area that lacks any pearl farms, it seems unlikely that a human inserted the metal core as a bead nucleus. It is possible that the core resulted from the pollution the region witnessed after the Gulf War in 1992, and a foreign metallic particle found its way into a mollusk. Residue from the shipping industry is another possibility, with potential pollution from the heavy volume of oil tankers and other vessels in the area. Hence, water contamination may be a convincing explanation for the unusual structure observed in this unique and fascinating natural Kuwaiti pearl. @chapter:14


Publication Year: 2024 Title: “Lily Pad” Structure in an Orangy Yellow Pearl Abstract: Figure 1. The orangy yellow pearl weighing 4.14 ct and measuring 9.51 × 8.43 × 7.51 mm. Photo by Gaurav Bera.
GIA’s Mumbai laboratory recently received for identification an orangy yellow semi-baroque pearl weighing 4.14 ct and measuring 9.51 × 8.43 × 7.51 mm (figure 1). Externally, the pearl had a distinct indentation on its top portion and possessed a medium surface luster. Observation of the surface under 40× magnification showed typical fine overlapping platelets of aragonite.
Energy-dispersive X-ray fluorescence revealed a manganese level below detection limits and a strontium level of 1226 ppm. When exposed to X-ray fluorescence, the pearl showed an inert reaction. Both results confirmed the pearl’s saltwater origin. Under long-wave ultraviolet light, it exhibited a yellowish green reaction. Raman analysis using a 514 nm laser excitation revealed a doublet at 701 and 704 cm–1 and a peak at 1085 cm–1, indicating the presence of aragonite. Photoluminescence spectra revealed two strong broad peaks at 620 and 650 nm as well as one weak peak at 680 nm, confirming the pearl’s natural color origin.

Figure 2. A: RTX image revealing a unique acicular “lily pad” feature with tiny flame-like structures. B: μ-CT scan displaying a small central core with elongated spiky features. C: A magnified μ-CT scan showing the spiky features surrounded by prominent growth arcs.
Upon further testing using real-time X-ray microradiography (RTX), the pearl displayed an unusual acicular feature resembling the shape of a lily pad, with tiny flame-like structures radiating from the center. This feature was intersected by several growth arcs (figure 2A). X-ray computed microtomography (μ-CT) provided a more detailed view, revealing a distinct small void at the center. Surprisingly, the acicular “lily pad” feature observed in the RTX images appeared as numerous elongated, spiky structures with very fine lines cutting through the shape (figure 2, B and C).

Figure 3. The 3D models generated using μ-CT scans show the acicular feature in red resembling a lily pad with a small core at the center, while the green area represents the pearl’s growth structure.
To further study this feature, three-dimensional models were created using specialized software to render the μ-CT scan images (C. Zhou et al., “New 3-D software expands GIA’s pearl identification capabilities,” GIA Research News, May 13, 2016). In both the μ-CT scan images and the 3D models shown in figure 3, it was evident that this unique feature was confined to the central part of the pearl and did not extend to the outer nacre layers. Notably, the lily pad feature had elongated spikes that were thicker at one end and gradually tapered as they radiated outward from the center.
Gemological laboratories do encounter pearls with internal structures that are very difficult to positively identify. Due to the lack of conclusive evidence proving it was a cultured pearl combined with the presence of a rare and distinctive natural structure, this pearl was considered noteworthy. Such intriguing natural growth structures can be influenced by several factors, including environmental conditions, the health of the mollusk during formation, and other external causes impacting the pearl formation process. The precise mechanism of natural pearl formation continues to be widely debated, and encountering such pearl samples causes us to further contemplate the creation of these exquisite gems. @chapter:14


Publication Year: 2016 Title: Natural Blisters with Partially Filled Areas Abstract: Figure 1. The four large baroque blisters examined are shown alongside a Pinctada maxima shell (left), a Pteria sterna shell (second from the left) and two Pteria penguin shells. Photo by Lhapsin Nillapat.

	Natural blisters and blister pearls have been the subject of previous reports in G&G (see Lab Notes from Fall 1992, Spring 1995, Winter 1996, and Winter 2015, and Gem News International from Fall 2001 and Winter 2009). In February 2016, four large “pearls” (figure 1) were submitted to GIA’s Bangkok laboratory for identification. On first impression they appeared to differ from most pearls or blister pearls examined in the past. The specimens ranged from approximately 25.06 × 18.31 × 13.41 mm to 55.90 × 13.89 × 7.96 mm, and they weighed 32.33, 37.20, 41.41, and 52.17 ct. Two of the items were white, and the other two were silver and orangy brown.

	All the samples had eye-visible areas on their bases and around their outlines where they had obviously been worked or cut to either remove them from their shell hosts or improve the symmetry (in some cases both). These are telltale signs of blisters and blister pearls, since both must be removed from the shell to be presented in loose form. What caught our attention was the fact that all four items possessed dark or cream bands on their bases (figure 2). These bands appeared to be organic-rich formations, noted in some pearls and more commonly in shells, yet this did not turn out to be the case in three of the samples.

Figure 2. Dark and cream-colored bands on the bases appeared to be organic-rich formations. Photo by Lhapsin Nillapat.

	The items were considered blisters rather than blister pearls (E. Strack, Pearls, Ruhle-Diebener-Verlag, Stuttgart, Germany, 2006, pp. 115–127). This determination was based on external appearance and features, the “work” that had taken place on them in relation to where they were likely removed from the shells, and the results of real-time X-ray microradiography (RTX), which revealed growth arcs following the shape of the blisters to varying degrees.

	The curving black band on the base of the smallest white blister contained translucent to opaque organic-looking material characteristic of conchiolin (figure 3A), one of the constituents of pearls and shells. The remaining three blisters had structures within their bands that did not match the structure observed in the first blister. The bands in the two orangy brown blisters consisted of an essentially transparent near-colorless substance in which minute black pinpoint particles imparted an overall black color (figure 3B). Meanwhile, the band in the remaining white blister showed areas of completely transparent near-colorless material and other areas of the same near-colorless material, mixed with small pieces of what appeared to be shell fragments. Distorted bubbles were clearly visible in the transparent areas on the base of the partially filled white blister (figure 3C) and one of the colored blisters (figure 3D); no obvious bubbles were seen in the other blister. RTX also revealed the extent of the filling on the bases of the three blisters.

	Figure 3. A: Part of the dark conchiolin-rich curving band on the flat base of the 32.33 ct white blister; field of view 2.88 mm. B: Black pinpoint particles in the transparent near-colorless filler on the base of the 37.20 ct colored blister; field of view 1.20 mm. C: Distorted bubbles in the transparent filler on the base of the 41.41 ct white blister; field of view 2.40 mm. D: Obvious bubbles in the filler on the base of the 52.17 ct colored blister; field of view 2.40 mm. Photos by Kwanreun Lawanwong.

	Raman spectroscopy of the near-colorless filled areas of the two colored blisters did not show any polymer or resin peaks that matched those found in the white blister’s filling. Therefore, we conducted basic testing on all three samples with a very carefully placed hot point in areas of the filling where some damage or abrasion already existed. The unmistakable plastic odor and melting of the tested areas was enough to confirm the artificial nature of the fillers. Interestingly enough, the fillers did not display a noticeable fluorescence under long-wave or short-wave ultraviolet light, but the two orangy brown blisters did exhibit distinct orange to orange-red fluorescence, which is characteristic of the porphyrins (naturally occurring pigments) known to exist in Pteria species shells of similar coloration (L. Kiefert et al., “Cultured pearls from the Gulf of California, Mexico,” Spring 2004 G&G, pp. 26–38). Out of curiosity, we also checked the dark conchiolin-rich band in the smaller white blister with the hot point and fluorescence. It was no surprise to smell a distinctly unpleasant organic reaction from the band and see a weak chalky yellowish reaction under UV lighting.

	These four blisters were good examples of this material, and three of them were the first partially filled blisters to be examined by GIA’s Bangkok laboratory. The three partially filled blisters show that even material with relatively low market value may be treated in some way, and buyers should always be aware of what is being offered to them. @chapter:14


Publication Year: 2019 Title: The Rock Hound: Muzo Emeralds and Ethical Practices Abstract: Figure 1. The centerpiece of the Molten Muzo collection, the “Candelabra” necklace features 20.63 carats of responsibly sourced Colombian emeralds. Photo by Kevin Schumacher, courtesy of The Rock Hound.

At the JCK Tucson show, Susi Smither (The Rock Hound, London) displayed pieces that showcase her love of gemstones and her passion for color. Combining technical knowledge with aesthetics to create unique lines, Smither refers to her business as “the gemologist jeweler,” and receives a number of commissions from gemologists. She offers jewelry at multiple price points, ranging from $400 to $11,000. A major point of pride for Smither is Molten Muzo, a five-piece fine jewelry collection launched in December 2018. One of 25 international jewelry designers selected by Muzo Emerald Colombia for collaboration, Smither combined ethically sourced emeralds in tumbled form with Fairtrade 18K yellow gold. The “Candelabra” necklace, the collection’s lead piece, is shown in figure 1. The collection also features two pairs of earrings and two rings, one of which is shown in figure 2. Smither allows the emeralds to steal the show; the gold “dripping” from the gemstones complements, rather than overtakes, the simplicity of the tumbled stones.

Figure 2. Left: The “Drip” earrings from the Molten Muzo collection use 16.22 carats total of emerald, catching the light as the wearer moves. Photo courtesy of The Rock Hound. Right: An inner world is visible in this 11.05 ct emerald, from one of two rings in the collection. Photo by Kevin Schumacher, courtesy of The Rock Hound.
The daughter of mineral collectors, Smither entered the industry as a jewelry designer and maker about 10 years ago. As she took on more commissioned work, she earned her FGA diploma from Gem-A, immersing herself in the world of “science and beauty.” During a field trip to Sri Lanka with the Scottish Gemmological Association in 2012, she was struck by the disparity between the luxuriously appointed jewelry shops of Hatton Garden and Bond Street and the gritty, often dangerous reality of mining. Thus, at the core of Smither’s brand are her ethical practices. The Rock Hound has been a Fairtrade licensee since its inception in 2015, using only recycled gold and Fairtrade Gold from Peru.

Figure 3. Pieces from The Rock Hound’s Chromanteq line. Left: This pendant features a 6.48 ct Brazilian heliodor in an 18K recycled white gold setting and an 18K yellow gold chain. The pendant’s blue color comes from a signature ceramic coating. Right: The rings in this line also use the ceramic coating. The ring on the left uses 18K recycled white gold and is set with a 9.95 ct Afghani peridot. The ring on the right has a 2.38 ct Tanzanian spessartine set in 18K recycled yellow gold. Photos by Kevin Schumacher, courtesy of The Rock Hound.
Smither noted that the industry has evolved even since The Rock Hound began. Last year she found a casting house in the UK that creates three different alloys of 18K gold three times a week, opening the doors for a fully Fairtrade Gold collection called RockStars, inspired by the shape of a natural tourmaline crystal. To ensure the integrity of her supply chain, she works with artisanal lapidaries who go into the field to work with mining communities. Stones sourced in this way are used in her Chromanteq line, which sets colored gemstones in ceramic-coated recycled 18K gold (figure 3).

	The Rock Hound

Smither’s commitment to responsible standards extends to her packaging, made from the perch leather that is a byproduct of the fishing industry. She has sometimes had to choose from a limited selection of materials due to her commitment to responsible sourcing. As a result she would design once she procured her materials rather than designing solely with good in mind. However, she feels that as a young designer starting out, she was better positioned to put sustainable practices in place. Trying to replace longstanding protocols would have been far more difficult for an established business. As this type of sourcing becomes more widespread, she feels that she can expand the design side of The Rock Hound—these days, Smither is “dreaming bigger.” She is eager to create new lines for the next wave of consumers who are equally passionate about sustainable jewelry. @chapter:34


Publication Year: 1999 Title: Sapphire and Garnet from Kalalani, Tanga Province, Tanzania Abstract: Located just 3 km south of the famous Umba locality, the geologically similar Kalalani area hosts deposits of gem-quality sapphire (reddish orange, yellow-brown, and other colors), pyrope-almandine, and tsavorite. The gems are mined principally from primary and eluvial sources associated with a serpentinite body and surrounding metacalcareous rocks. The gemological properties of sapphires from Kalalani are very similar or identical to those from Umba. The garnets, however, are different: Tsavorite is not known from the Umba area, and the dark red to brownish red pyrope-almandine from Kalalani is distinct from the pink-purple rhodolite more commonly found at Umba. @chapter:5


Publication Year: - Title: Very Large CVD Synthetic Diamond Abstract: Figure 1. This 2.16 ct marquise (13.42 × 6.73 × 3.94 mm) is the largest CVD synthetic diamond tested by GIA. It had J/K color, with a brownish tint. Photo by Jian Xin (Jae) Liao.

                      In the last decade, we have witnessed rapid improvement in the quality and size of lab-grown CVD synthetic diamonds. The GIA New York laboratory recently tested a 2.16 ct CVD synthetic from Scio Diamond Technology Corp. (figure 1), the largest specimen GIA has seen so far.

This marquise, which measured 13.42 x 6.73 x 3.94 mm, was more than twice the size of a 1.05 ct pear shape examined in 2010, previously the largest CVD synthetic tested by GIA (see Summer 2010 G&G Lab Notes, pp. 143–144). It had J/K color with a brownish tint, and microscopic observation revealed small fractures, pinpoints, and non-diamond-carbon black inclusions, resulting in an SI2 clarity grade.

The mid-infrared absorption spectrum showed the features of type IIa diamond. It was very pure in the infrared region, with no nitrogen- or hydrogen-related absorption features. Photoluminescence analysis at liquid-nitrogen temperature with varying laser excitations displayed typical CVD features: very strong emissions from N-V centers, moderate emission lines at 736.6/736.9 nm from the [Si-V]- center, and the CVD-specific 596/597 nm pair (figure 2). Also detected was weak emission from the H3 defect with a zero-phonon line at 503.1 nm, making for an interesting combination of optical centers. Under the short-wave UV radiation of the DiamondView, the table and crown facets showed pure blue fluorescence while the pavilion displayed banded orange fluorescence with irregular blue fluorescence regions. Very strong internal stress with irregular patterns was confirmed under the microscope using cross-polarized light.

	Figure 2. The 2.16 ct synthetic showed typical photoluminescence features of CVD growth, including strong emissions from N-V centers at 575 and 637 nm, moderate CVD-specific emissions at 596/597 nm, and 736.6 and 736.9 nm emissions from the [Si-V]– center.
Testing of this large, gem-quality CVD synthetic underscored the rapid improvement of lab-grown diamond technology. It is foreseeable that more of these products will continue to reach the jewelry industry.

Read More Lab Notes. @chapter:15


Publication Year: 1995 Title: Spring 1995 Gem News International Abstract: TUCSON ‘95
Diamonds
            New Diamond Cuts
Colored Stones
            Large Apatites from Madagascar
            Diaspore from Turkey
            Cat's-Eye and Trapiche Emeralds
            Emerald Necklaces Fashioned in India
            Garnets from Mali
            Fashioned Natural Glasses
            Fashioned "Rainbow" Hematite
            Iolite and Other Gems from Madagascar
            Iolite and Other Orissa Gems
            More Meteorite Products
            "Strawberry" Quartz and Other Russian Gems
            Miscellaneous Notes on Sapphires
            Sapphires from Tanzania
            Faceted Sphalerite and Other Collector Stones from Canada
            Swarovski Debuts Machine-Cut Gems
            Topaz and Beryl from the Ukraine
            Miscellaneous Notes on Tourmaline
Instrumentation
            Inclusion-Viewing System
            New Magnet for Gem Testing
Synthetics and Simulants
            Faceted Kashan Synthetic Rubies and Sapphires
            More Russian Synthetics and Simulants
            "Recrystallized" Synthetics
            Synthetic Zincite from Poland
            New Source of Synthetic Emeralds
Enhancements
            Diffusion-Treated Sapphires

To view the full section, download the PDF above. @chapter:23


Publication Year: 2017 Title: World of Gems Conference Abstract: Figure 1. A gathering of the presenters at the fifth World of Gems Conference, held in Chicago in September 2017. Photo by Scott Drucker.

The Gemworld International team, headed by Richard Drucker, hosted the fifth World of Gems Conference September 23–24 at the Loews Hotel in Chicago. The event was bookended by optional classes, making it an ideal opportunity for attendees to learn about new topics from a diverse group of international speakers (see above) and brush up on their practical gemology skills. Between presentations, the conference held its first-ever poster session. The posters included interactive discussions on jet and the identification of light blue stones using the polariscope and the conoscope, hosted by Sarah Caldwell Steele (Ebor Jetworks, Whitby, United Kingdom) and Kerry Gregory (Gemmology Rocks, Weavering, United Kingdom), respectively.

Invited speaker Emmanuel Fritsch (University of Nantes, France) opened with a talk about the identification of melee synthetic diamonds. He noted that while the majority of specimens are not hard to identify, near-colorless HPHT-treated synthetic melee may still be challenging. Dr. Fritsch also provided a brief history of synthetic diamond production and the current state of the industry, as well as basic and advanced methods of separating synthetic from natural. Isotropy and anomalous double refraction—otherwise known as strain—were covered in some detail, as he considered these very useful identification aids. Jon Phillips (Corona Jewellery Co., Toronto) reviewed world diamond production and the output of mines such as Jwaneng in Botswana, which accounts for 15% of total global production. Meanwhile, Canada’s five operating mines rank among the top 19 producers. One key takeaway from his talk was that De Beers plans to invest US$140 million on a marketing campaign aimed at women buying diamond jewelry for themselves. This should not be ignored by jewelers. Mr. Phillips also reflected on the threat of synthetic melee in the market. This author (GIA, Bangkok) reviewed the different types of pearls (nacreous and non-nacreous) seen in the market and the various mollusks that produce them. The presentation detailed the surface structures of a wide selection of non-nacreous pearls and concluded with a summary of the more frequently encountered treatments. Roland Schluessel (Pillar & Stone International, San Francisco) provided a comprehensive look at Burmese jadeite and defined the various types, including the term fei cui (kingfisher) for the vivid green variety. He examined cultural aspects and discussed factors such as grain size and orientation, which relate to transparency and overall quality. Mr. Schluessel also provided insight into the different colors and patterns, as well as the differences between omphacite and jadeite. Ҫiğdem Lüle and Stuart Robertson (Gemworld International, Glenview, Illinois) reported on various gem treatments that provide enough supply to satisfy market demand. Frequently encountered treatments and the pricing of untreated vs. treated material were reviewed. Diamond was offered as an example of a gem where treatments markedly affect the end value, while tanzanite shows little if any price difference between natural and treated material. A very lively presentation from Kerry Gregory about the daily happenings in the pawnbroking world rounded out day one. Ms. Gregory discussed some of her experiences saving valuable pieces that would have otherwise been destroyed due to lack of resources, training, and time. She also provided insight into her use of simple yet valuable gemological methods (such as the polariscope and conoscope) in identifying light blue stones removed from items destined for the melt.

J.C. (Hanco) Zwaan (Netherlands Gemmological Laboratory, Leiden) started the second day with a comprehensive look at the geological formation and gemological characteristics of metamorphic sapphires from Sri Lanka and to a lesser extent Montana. The search for a primary sapphire deposit in Sri Lanka and the discovery at Wellawaya (which Dr. Zwaan was involved with) were illustrated. Subsequent discussions on the use of chemical plotting in the separation of Sri Lankan and Montana material, from one another and from other sources, showed that it is beneficial but care is still needed with some cases that may overlap. Ҫiğdem Lüle followed with a solo talk about the various natural and “non-natural” black gem materials and the limitations encountered when testing such materials. She covered black diamonds in some detail, outlining the differences between the rare naturally colored stones and heated or irradiated specimens. Al Gilbertson (GIA, Carlsbad) reported on the status of GIA’s fancy-cut diamond grading project and showed the challenges faced when producing a system that takes all variables into consideration and satisfies all opinions. This was reinforced after receiving feedback from 440 participants in six global locations who were asked to look at various fancy cuts and answer a series of questions. Alan Bronstein (Aurora Gems, New York) took attendees on a journey through the colorful world of fancy-color diamonds, looking at the subtleties of the main colors available: yellow, orange, pink, red, green, and blue. Mr. Bronstein was clearly in favor of retaining the original cut of a diamond and not re-cutting it. Chameleon diamonds were also briefly covered. “Beauty trumps rarity” was Mr. Bronstein’s motto. Richard Drucker brought the presentations to a close with a look at some challenges that affect the pricing of gemstones. From the small print in pricing guides that might not be fully understood by users to gemological reports that raise doubts or cause confusion in appraisers’ minds, it became very apparent that the valuation of some colored stones needed careful thought.

The conference ended with a Q&A session in which Mr. Drucker opened the floor to all attendees. Topics such as correct nomenclature and disclosure, brand name cooperation with items submitted for valuation, and color diamond grading consistency were covered. @chapter:29


Publication Year: 2017 Title: Screening of Mounted Melee Using the GIA iD100 Abstract: Figure 1. A diamond ring with 100 melee side stones incorporated into the setting. Photo by Sood Oil (Judy) Chia.

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

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

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

Figure 3. The referred melee displayed strong phosphorescence to short-wave UV radiation, as is typical of HPHT-grown synthetic diamonds. Image by Paul Johnson.
This ring offered an excellent example of how the GIA iD100 can quickly screen very small mounted diamonds and accurately detect any synthetics or even simulants. @chapter:15


Publication Year: - Title: Alumni Couple Garners Hollywood Attention by Marrying Avant-Garde, Art Deco Designs Abstract: This Kavant and Sharart pendant features diamond and two individual slices of agate, purchased on one of the couple’s buying trips to Tucson.  Courtesy Kavant and Sharart

                      Their designs are splashed on the covers of magazines from Cosmopolitan to Marie Claire. They count superstars Katy Perry, Miranda Lambert, Gabrielle Union, K risten Stewart and Kylie Jenner among those who have been photographed in their luxury jewelry.

Kavant and Sharart, the Thailand-based design house − comprised of husband and wife team Nuttapon (“Kenny”) Yongkiettakul and Shar-linn Liew − has collectively earned two Centurion Emerging Designer Awards, a JCK Jewelers’ Choice Award, a GIA Student’s Choice Award and recognition from the Cultured Pearl Association of America.

	Singer Katy Perry wore a one-of-kind piece from Kavant and Sharart while performing at the “Change Begins Within: A David Lynch Foundation Benefit Concert” in New York City on November 4, 2015. The two-finger “Le Phoenix” ring features morganite and diamond.  Courtesy Kavant and Sharart
The couple’s acclaim within both design and jewelry-loving celebrity circles is, in large part, due to innovative designs like their self-coined “eartux.” Taking inspiration from the ear jacket concept, the piece goes a step further – making it appear as if the wearer has multiple piercings. Victoria’s Secret “angel” Adriana Lima has worn the eartux (and many other Kavant and Sharat pieces), and that design alone has been featured in    Women’s Wear Daily , JCK and W Magazine.

Popular “Gem Gossip” fashion blogger (and Kavant and Sharart fan) Danielle Miele, a fellow GIA alum, says she was “quite impressed” with the Yongkiettakul’s and Liew’s designs as soon as she previewed their first collection.

“They make a unique husband and wife duo,” Miele says, “as both of their styles juxtapose one another in the best way possible.”

The core of Kavant and Sharart’s “aesthetic and philosophy” emphasizes their individual styles − and celebrates that of the woman wearing it.

“We believe it’s crucial to stay true to who you are, to focus on innovating and exploring your own sense of style,” says Liew, a GIA GG and AJP. The core of their “aesthetic and philosophy” follows that lead, she says, so they create “luxury jewelry that not only satisfies the wearer’s need to wear something charming, but also her desire for something original that highlights her personality through effortlessly elegant accessories.”

	Kenny Yongkiettakul’s “avant-garde and organic” style takes inspiration from nature and the ocean, as seen in these Kavant and Sharart pieces – orange sapphire and diamond earrings, and yellow sapphire and diamond earrings featuring Baroque South Sea pearl. Courtesy Kavant and Sharart
The couple’s different styles and inspirations – his, “avant-garde and organic, inspired by nature and the ocean” and hers, rooted in Art Deco, Oriental and Modern arts, inspired by geometric shapes – were each nurtured in childhood.

Yongkiettakul, a GIA GJ, GG, AJP and AJA, grew up in his family’s Bangkok jewelry store, which he watched grow from the “very humble beginnings” of a single retail counter near the city’s Victory Monument. Though Yongkiettakul studied chemical engineering in college, he joined his family’s business after graduation.

“Since I was young, my dad was always telling me about GIA, and that I must attend this prestigious school one day,” he says. “It was ingrained in my mind.”

Liew began dreaming of design as a young girl in Singapore, following her dress-maker/fashion-designer mother through the fabric markets of Hong Kong and into meetings with seamstresses.

“My mother had a very good eye for proportions and color concepts, and her attention to detail was acute,” she says. “I was immensely inspired. The concept of proportion and balance in design was instilled in me since I was young.”

The couple, who met in 2003, moved to California to pursue Yongkiettakul’s studies at GIA Carlsbad in 2007. Liew soon followed suit.

“My interest grew when Kenny shared his wonderful experience,” she says. Liew graduated with her Graduate Diamonds diploma in 2007 and later earned her AJP and her GG on campus in Thailand.

	The eartux is a signature Kavant and Sharart design. Clockwise from top left, the Le Phoenix Single Claw Rhodolite Garnet Eartux; the Le Phoenix Enchanted Diamond Eartux in 18K rose gold; and a pearl version of the design. Courtesy Kavant and Sharart
When the couple eventually prepared to marry, they also decided they wanted to merge their styles in one brand.

“We knew we wanted to work together when we were designing my wedding jewelry,” Liew says. “It was a logical transition to merge our two brands into one. Although we have different design aesthetics, the merge also allowed something for everyone – marrying the two different aesthetics somehow worked. We’re putting a woman’s and man’s perspective into one piece.”

They each procure gemstones and create designs for Kavant and Sharart, with Yongkiettakul managing most of the company’s quality control.

“I think the beautiful part about [our career] is being able to express our love for design through jewelry and gemstones,” Liew says. “Being able to materialize a design from a sketch to a finished product – and subsequently, when a customer buys it – the sense of fulfillment is very satisfying.”

	Kavant and Sharart is comprised of husband and wife team Kenny Yongkiettakul and Shar-linn Liew, both award-winning designers and GIA graduates. The pair is grateful for the guidance they received at GIA and want to do the same for current students. “Keep in touch with friends and teachers,” says Yongkiettakul. “We have been very blessed with mentors along the way, and we hope to help fellow GIA students in any way we can. Our doors are always open.” Courtesy Kavant and Sharart
Yongkiettakul says that GIA prepared the couple well for their careers.

“GIA serves as a solid foundation for anyone interested in this trade,” he says. “The knowledge you gain throughout your education will serve you well, but it’s definitely important to keep up with the latest news in the industry through journals like  Gems & Gemology  and visiting trade shows.”

As much as their GIA experience was “intense and fast,” it was also “enlightening and inspiring,” he says.

“Give it your best at each level, because six months fly by,” he says. “All the resources are in your hands.” @chapter:36


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

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

Figure 3. High-quality opal from Brazil shows extremely vivid play-of-color. Some are of transparent light gray to white bodycolor such as this 132.3 ct freeform (left), while others have darker bodycolor (right). Photos by Robert Weldon; courtesy of Prime Gems.
Prime Gems offered Brazilian opal with transparent light gray to white bodycolor from Pedro II, similar in appearance to white opal from Australia (figure 3, left). The play-of-color was especially charming in less transparent pieces that showed colors of the whole spectrum, with bluish and greenish colors most commonly displayed. Red play-of-color is rarer and more sought after, with a higher price tag. Some pieces with darker bodycolor resembled Australian black opal (figure 3, right).
Finished products available at the show included loose opal as cabochons, freeform polished singles or pairs, doublets, and some mosaic pieces. The top-quality materials displayed a vibrant whole-spectrum play-of-color. Opal that was of good quality but too thin for freeform single pieces was used to make doublets, with the thin opal layer glued to a dark base. To support local communities, mine operators allow the local people to use very small pieces of opal from mine waste to create mosaics for sale. The supplemental income from the sales of the mosaics can reach as much as $30 per day.
The miners informed the author that Brazilian opals are sometimes sold as Australian in the marketplace. Brazilians are proud of the quality of their opal, and opal from Pedro II is one of the two products from the state of Piauí that bear the Geographical Indication certificate. The Brazilian government grants this GI label to products or services that are characteristic of a region. The aim is to ensure that Brazilian opal is properly represented and can generate revenue to further support mining and the local communities. @chapter:39


Publication Year: 2016 Title: A Fantastic Display of Phase Changes in a Sapphire’s Fluid Inclusion Abstract: This negative crystal, measuring 1 mm in length, contains a large graphite crystal and carbon dioxide. When cooled below the supercritical point, the CO2 exists as a gas and liquid; gas bubble gaseous CO2 is visible due to the difference in refractive index between the liquid and gas phases (B–F). When heated above the supercritical point, the CO2 homogenizes into a supercritical fluid (A and G). The flat surface of the negative crystal gives rise to a high nucleation density of gas bubbles, which ultimately coalesce into a single large (B and E). Photomicrographs by Nathan Renfro.

	In corundum of metamorphic origin, the presence of carbon dioxide (CO2) fluid inclusions is a useful diagnostic indicator that no heat treatment has occurred; a gemologist simply has to cool the stone to below approximately 31.5°C to observe these inclusions (J.I. Koivula, “Carbon dioxide fluid inclusions as proof of natural-colored corundum,” Fall 1986 G&G, pp. 152–155). Even though this type of inclusion is considered commonplace in sapphires that form in a metamorphic environment, a spectacular example was recently witnessed in a Sri Lankan sapphire.

	Sapphire's Fluid Inclusion

	Temperature and pressure conditions create phase changes in this Sri Lankan sapphire's negative crystal inclusion.

	When viewed correctly, the inclusion is revealed to be a negative crystal with a very tabular morphology (figure 1); for more on distinguishing negative crystals, see Fall 2009 Lab Notes, pp. 212–213. The negative crystal also contains a rather large graphite crystal. As the specimen’s temperature is lowered, the CO2 trapped in the negative crystal remains homogenized with no bubbles present until reaching approximately 31.5°C, whereupon both liquid and gas phases become clearly observable. The homogenized state represents a supercritical fluid, one that behaves like a liquid and a gas under certain conditions. Under these circumstances, the CO2 assumes the shape of its “container” (the negative crystal) and can be compressed much like a gas phase while retaining the density of a liquid. This supercritical phase of CO2 has some unique properties, such as the ability to dissolve certain substances, which is otherwise impossible in its gas or liquid phase. The observation of the phase change elegantly illustrates the temperature and pressure conditions of this fluid inclusion system. Such inclusions generate pressure 75 times that of sea level (>1000 psi), and this extreme pressure accounts for their tendency to rupture during heat treatment (see E. Roedder, Fluid Inclusions, Reviews in Mineralogy, Vol. 12, Mineralogical Society of America, Washington, DC, 1984).

	When CO2 is cooled below 31.5°C, the liquid and gas phases have very different densities and thus very different refractive indices, making them clearly distinguishable. Above that temperature, while in the supercritical state, the homogenized liquid has a uniform density, and the two phases are impossible to differentiate. As one raises and lowers the temperature, the changing internal scene repeatedly follows this fascinating course.

	In this example of a CO2-filled negative crystal, numerous bubbles spontaneously nucleate as the temperature drops below the supercritical point. This proliferation is largely due to the flat, smooth surfaces of the tabular void. The highest-energy areas for the bubbles to nucleate exist on minute imperfections along these flat surfaces, creating an extraordinarily high nucleation density of gas bubbles. This is one of the most fantastic examples of a carbon dioxide fluid inclusion phenomenon the authors have encountered in sapphire. @chapter:19