# Publication Year: 2017
# Title: Fine Gems and Update from Myanmar
# Abstract: Figure 1. Suites combining blue-to-violet pastel colored spinels with red to rose-colored gems of similar tone. The blue gems range from 3.63 to 8.30 ct and the pink to red examples from 3.16 to 5.70 ct. Photo by Albert Salvato; courtesy of RareSource.

At the AGTA GemFair, Edward Boehm (RareSource, Chattanooga, Tennessee) showed us a succession of top-quality gems. Boehm is a geologist, gemologist, and accomplished gem dealer who works with rare and higher-end gems. He noted that the price of spinel from Myanmar has increased dramatically, with recent prices at the source more than double those of previous years. He explained that spinel has gained favor in Myanmar, which is reflected by the higher prices at this year’s show.

Boehm noted that a growing appreciation for spinel from all sources is driving higher market prices. As an example, he showed us a beautiful oval 21.56 ct Sri Lankan pink spinel cut to make the most of the gem’s high clarity and moderate dispersion. The size, clarity, and brightness are reminiscent of Tajik spinel. He compared this bright lilac pink Sri Lankan spinel with a strong orangy red square cushion-cut 9.82 ct Burmese gem, which he described as having a “flame” color. The per-carat price of the flame-colored Burmese stone is almost double that of the Sri Lankan spinel—$12,000 per carat wholesale versus $7,000 per ct. A strong red “flame” color makes the price jump significantly. If the stone were above 10 ct, Boehm added, the price would further jump to around $15,000 per carat.

	Edward Boehm - RareSource

In this video, Edward Boehm presents a selection of high-end gems, including red and pastel-colored spinel, spessartine garnet, peridot, demantoid garnet, sphene, and untreated Madagascar morganite. He concludes with a spectacular 31.79 ct Sri Lankan padparadscha sapphire.
Pastel blue to violet spinels are also selling well for Boehm. Designers like to mix these delicate blues with pinks or “rose” colors of similar tone and saturation to produce very attractive suites and sets. The pinks help to highlight the violet or purple in the pale blues, he added. The bluish violet examples he showed us hailed from Sri Lanka and wholesaled for $1,200–$1,500 per ct (figure 1). Complementary rose-colored gems came from a variety of sources—including Vietnam, Sri Lanka, and Myanmar—and ranged from $1,000 to $1,800 per ct.

Boehm explained that the most sought-after color is the “electric” haüyne blue, which comes from Luc Yen, Vietnam, and is only sporadically available in small sizes. He added that the light-toned, gray-to-violet blue colors are more available than in the past—partly because there’s more demand so more people are bringing it to market.

Like Burmese spinel, Burmese peridot is currently in vogue. Boehm showed us a fine 20.41 ct cushion-cut gem (figure 2). The presence of a multitude of tiny inclusions lend it a softness and reduce extinction. By comparison, fine Pakistani peridot—which is also available in large sizes—has a more “crystalline” appearance and deeper color, but shows more extinction. He explained that the price of Burmese peridot has recently gone up sharply. A top gem like the one in figure 8, which would formerly have been in the $250–$350 per carat range, is now wholesaling for $450–500 carat and even up to $600 per carat. He cautioned buyers to check whether a stone shows doubling in the pavilion in the face-up position, which is considered less desirable. Buyers want to ensure the stone is oriented in such a way that doubling isn’t visible through the table.

Figure 2. This cushion-cut 20.41 ct Burmese peridot shows a softer appearance due to a multitude of tiny inclusions. Photo by Albert Salvato; courtesy of RareSource.
Next, he showed us a rich green, 4.81 ct cushion-cut demantoid garnet from Russia, which contained a golden-colored horsetail inclusion. Such a gem would wholesale for $15,000 per ct, he said. According to Boehm, gems of such pure green color rarely come out of the ground—they are typically heated to this color. This treatment has been going on for 10–15 years, he explained. Despite this treatment, the demantoid is still an exceptional stone.

Boehm explained that judicious heating converts a yellowish green gem to a vibrant green but removes some of the stone’s characteristic fire, making it an almost “electric” green color. He prefers a balance of color and fire, acknowledging that the gem’s inherent fire—flashes of red and blue coming off a green bodycolor—is part of its unique appeal. In today’s market, any demantoid over 2 ct is extremely rare, so this gem’s size of almost 5 ct makes it very desirable.

The demantoid was from new production rather than the secondary market, Boehm explained. He added that there is still newly mined supply and treaters are perfecting heating techniques to make gems much more vivid, although not all respond like this one.

Finally, he showed us a striking 31.79 ct Sri Lankan pear-shaped sapphire with padparadscha color—a delicate pink flushed with a bloom of orange (figure 3). He explained that the gem had been recut three times to perfect its shape and proportions. The objective of recutting the original old-style cut was to close the window on the pavilion, but any further work would affect the brilliance and might even lose the cherished pinkish orange color. He added that when cutting padparadscha sapphire, it is very hard to keep that balance of pink and orange, because sometimes the orange might be in just one portion of the stone, which could easily be removed accidentally. A gem of this size is enormous for a padparadscha, he noted, and the wholesale asking price would be in the neighborhood of $30,000–$35,000 per ct.

Figure 3. This 31.79 ct Sri Lankan padparadscha sapphire shows the cherished combination of a pink bodycolor suffused with orange. Photo by Albert Salvato; courtesy of RareSource.
Boehm noted that on October 7, 2016, President Barack Obama signed an executive order lifting U.S. sanctions on Myanmar, allowing Burmese jadeite and rubies, and any jewelry containing them, to be imported into the United States. The sanctions had been imposed in 1997 (see https://www.treasury.gov/resource-center/sanctions/Programs/pages/burma.aspx).

Boehm felt fortunate to be in Mogok (figure 4) when the ban was lifted and was able to celebrate with many of the local miners and brokers. He hoped the change would significantly improve the supply of Mogok gems but anticipated that any increase in gems reaching the U.S. from this source would likely take some time. Most if not all Mogok mining licenses have been suspended as the Burmese parliament and ministries work together to rewrite mining laws in Mogok and the jade mining areas in Pagan. These laws have been in place for more than 100 years and have changed little.

Figure 4. In October 2016, an AGTA delegation visited gem markets and mines around the world-famous locale of Mogok. Their mission was to report back on conditions within the local gem and mining industry after the new government took office. Photo by James E. Shigley.
When Aung San Suu Kyi’s National League of Democracy party won a majority of seats in parliament during the November 2015 election, it was able to effect change with a special focus on the environment. The new administration’s objective is to make reclamation integral to obtaining a mining or prospecting license, so that when mining finishes, the licensee will be obligated to return the land to its original condition. The government wants to ensure these laws are enforced and that environmental and ethical standards conform to Western expectations for the gem mining sector. The aim is for the new mining laws to meet the internationally accepted standards outlined by the Organization for Economic Cooperation and Development (OECD), a group of 34 democratic countries that develop economic and social policy to support free market economies. These principles are laid out in the policy paper OECD Due Diligence Guidance for Responsible Supply Chains of Minerals from Conflict-Affected and High-Risk Areas (http://dx.doi.org/10.1787/9789264252479-en). For more information on corporate social responsibilities and ethical colored stone supply chains, please see J. Archuleta, “The color of responsibility: Ethical issues and solutions in colored gemstones,” Summer 2016 G&G, pp. 144–160).

	Edward Bohm – End of Burma sanctions

In this interview, Mr. Boehm explains the context of the recent lifting of the U.S. trade ban on imports of ruby and jadeite from Myanmar. He draws on his long experience of trading in Burmese gems to predict the supply of ruby to U.S. markets in the near future.
Boehm mentioned the recent AGTA October 2016 delegation (figure 5) to Myanmar that visited the cities of Yangon, Nay Pyi Taw, Mandalay, and Mogok. Along with other U.S. trade and industry bodies, AGTA is seeking to reestablish responsible gemstone trade between the two countries. This is only possible because of the political and economic progress Myanmar has made in the past six years, but it also depends on Myanmar’s gemstone sector meeting international standards such as OECD’s guidelines.

Figure 5. The October 2016 AGTA delegation at Mogok’s Taung ruby and sapphire mine. Edward Boehm and GIA’s Dr. Jim Shigley are at left. Photo courtesy of James E. Shigley.
The delegation, which included GIA researcher Dr. James Shigley and representatives from Jewelers of America, met with a cross section of stakeholders, including the U.S. ambassador, ministers and representatives of the Myanmar government, international and local organizations, trade associations, gem dealers and traders, and mine owners. They visited a number of gem markets and mines, including the Baw Maw mine (figure 6) and the Taung ruby and sapphire mine.

Figure 6. Workers sorting heavy mineral concentrate from the Baw Mar mine near Mogok.
Photo by James E. Shigley.
According to Boehm, the delegation was an impartial group sent to look at the situation “on the ground” in Myanmar, particularly in Mogok. He explained that it was an “eye-opening” experience and although conditions were much better than the group anticipated, there was room for improvement. The delegation made a series of observations that were set out in their white paper, Step by Step – Myanmar Gem Sector Emerges from Isolation and U.S. Sanctions, which is available from AGTA’s website at http://agta.org/info/docs/burmawhitepaper2016.pdf

Boehm indicated that Mogok was still beholden on the U.S. gem industry’s ongoing efforts to ensure that Myanmar’s government follows through with its promise to manage the gem sector properly and that the Burmese people benefit from the gems. He cautioned that a lot of mining licenses remain suspended. Therefore it’s very unlikely that U.S. businesses will see much production until these are reinstated, possibly in late 2017. He forecasts that the U.S. trade at large will have to wait at least another year before production appears in earnest. At that point, he expects many more U.S. buyers will travel to Mogok and competition for scarce goods will drive prices up, but at least the goods can be legally imported into the U.S. once more.

He reported that because of the government’s suspension of mining licenses, Mogok’s mines are currently closed again after a brief reopening. Boehm suspects several reasons for caution on the part of the authorities. Firstly, it would be very tempting for miners to produce as much material as possible now that dealers from the U.S. can legally buy gems in Mogok, so the government wants to buy time to regulate mining ethically to make sure the Burmese people are protected (figure 7). Secondly, they want to prevent large foreign investors from taking over the mining sector. Finally, there are some security issues with traveling the new road leading into Mogok at night, which the authorities want to correct before mining licenses are reinstated. Boehm considers these good signs that demonstrate the Myanmar government’s commitment to security and corporate social responsibility for the good of its citizens.

Figure 7. During the AGTA trip, delegates watched villagers searching for peridot in the waste tailings of the Pyaung Gaung mine near Mogok. Photo by James E. Shigley. @chapter:40 @chapter:0 @chapter:40


# Publication Year: -
# Title: Pearl Species and Localities
# Abstract: All GIA pearl reports include details about the mollusk (if determinable). The chart below and the downloadable PDF include more information about pearl species, localities, and growth, along with definitions for the 7 Pearl Value Factors™ and terminology GIA uses to describe your pearl.

	This information was included with Pearl Identification Reports and Pearl Classification Reports until March 2013. @chapter:11 @chapter:4 @chapter:11


# Publication Year: 2008
# Title: The Use of Laser and X-Ray Scanning to Create a Model of the Historic Koh-I-Noor Diamond
# Abstract: For centuries, the Koh-i-Noor was one of the world’s largest diamonds. It was recut in 1852 from its historic form of 186.1 old carats to an oval of 105.60 modern carats. While the modern shape is well documented, the original form is not. Fortunately, the Natural History Museum in London commissioned a mold of the diamond in 1851 before it was recut. Using one of two plaster replicas made from this mold, the present study captured the surface topology of the original Koh-i-Noor through photography plus laser and X-ray scanning methods. A crystallographic analysis of the major facets determined the diamond’s orientation within a “perfect” diamond crystal, which was used to refute one theory about the diamond’s genealogy. Computer modeling established the orientation of the recut diamond within the historic version. Information from this study was used to create an accurate replica from cubic zirconia. @chapter:41 @chapter:1 @chapter:41


# Publication Year: -
# Title: Searching for Sapphire in the Tasmanian Wilderness
# Abstract: View Gallery

Twentieth century Australian tin miners came across a deposit of material that was very different − and much more colorful − than what they expected: fine blue, green and yellow sapphire.

GIA field gemologists journeyed to the deposit near Weldborough in North Eastern Tasmania in 2012 and 2013 to gather samples for GIA’s reference collection, which is used for the Institute’s research and education programs. Field researchers went back to the Tasmanian wilderness in early 2015, bringing along the newest member of their team for hands-on training.

“The best way we can determine where a reference sample is from is to mine it ourselves,” said Vincent Pardieu, GIA’s senior manager of field gemology. “Knowing how to efficiently mine sapphires from a stream is a great skill for any field gemologist to have.”

Outfitted in wet suits and using traditional hand tools, the field gemologists worked tirelessly for three days in a stream surrounded by lush vegetation. They collected more than 200 sapphire samples, all of the basalt-related type, which are mostly blue with some yellow and green samples. In addition to sapphire, the team uncovered black spinel, zircon and topaz in the gravels.

“Digging for sapphire in Tasmania was tough, but extremely fascinating and rewarding,” said Stanislas Detroyat, a field gemology trainee at GIA. “I learned where to find sapphires in secondary deposits and felt the excitement of finally getting a sapphire from the field in my hands.”

Detroyat and Pardieu were accompanied by Didier Barriere Doleac, videographer; Chris Hood, gemologist and jeweler for Metal Urges in Tasmania; and expedition guests Eleonore Tatou, Marjorie Michel and Benjamin John. The team also had the opportunity to meet with Khin Zaw, research professor at the University of Tasmania, and Brendan M. McGee, a copper miner in Western Tasmania who wrote a thesis about Tasmanian sapphire under Professor Zaw’s supervision.

Background

In keeping with its mission to ensure the public trust in gems and jewelry, GIA regularly conducts research field trips to important gem and jewelry centers around the globe, incorporating findings into research practices and education programs and providing information to the trade and public. GIA appreciates the access and information provided during these visits; however, they should not be taken as or used as a commercial endorsement. Findings from the Tasmania field trip will be featured in an upcoming issue of G&G, as well as in field reports and video documentaries on the website. @chapter:4 @chapter:0 @chapter:4


# Publication Year: 2002
# Title: Summer 2002 Gem News International
# Abstract: Conference Reports
            AGU Meeting Examines Diamond Provenance
            GSA Meeting Reports on Western U.S. Gem Occurrences
            Report from the 3rd World Diamond Conference, Vancouver
Diamonds
            New Round Diamond Cuts
Colored Stones and Organic Materials
            Benitoite Recovery and Cutting: Significant Progress
            Cassiterite from Viloco, Bolivia
            Emerald with Feldspar Matrix from Brazil
            Sunstone Feldspar from Tanzania
            Update on Namibian Demantoid Garnet
            Unusual Kyanite from Brazil
            South Sea Cultured Pearls with Broken Beads
            Some Developments in Freshwater Cultured and “Keshi” Pearls
            New Sapphire Locality in Afghanistan
            Elbaite-Liddicoatite Tourmaline from Vietnam
            Green Zoisite Reappears
Synthetics and Simulants
            Massive Fuchsite Imitations of Emerald
            Unusual Synthetic Rubies
Treatments
            Another Identification Criterion for Imitation Asterism Produced by Surface Scratching
            Irradiated Color-Change Fluorite
Announcements
            Now Available: extraLapis English
Conferences
            Natural Glasses Scheduled for France in August
            Diamond 2002 Will Take Place in Spain in September
            Hong Kong Jewellery and Watch Fair Scheduled for September
Exhibits
Pearls Exhibit at the Field Museum
            Diamond Exhibition in Antwerp

To view the full section, download the PDF above. @chapter:1 @chapter:0 @chapter:1


# Publication Year: 2016
# Title: Fordite from the Corvette Assembly Plant
# Abstract: Figure 1. Three fordite slag specimens alongside a partially open piece that shows paint layers with various colors and thicknesses. Photo courtesy of Jay’s Minerals.

	Gemstone cutter and mineral specimen collector Jason Baskin of Jay’s Minerals (Flemington, New Jersey) presented some spectacular freeform fordite cabochons, a byproduct of an automobile painting process that is long gone.

	Workers once painted automobile bodies on train cars, which are commonly used on large assembly lines. As the paint was sprayed onto the target, the overspray collected on the train cars, and the accumulated layers of excess paint went together with the painted car body to the oven. The factory removed the accumulation periodically to clean the working platform and possibly recycle the paint. Mr. Baskin was informed by his contact in the factory that it takes about 997 layers of paint to build a one-inch-thick fordite slag specimen (figure 1). Since hand spraying has been replaced by powder painting, fordite is no longer produced, and the material on the market is all that exists. Fordite was first collected at Ford Motor Company in Michigan in the 1940s. The material saved from the 1960s and 1970s has the boldest colors, since cars were painted in very bright colors during that period.

	Mr. Baskin was introduced to fordite about three years ago by a friend and fellow gem cutter whose uncle worked at the Corvette assembly plant in Bowling Green, Kentucky. Mr. Baskin and his friend now own a substantial collection of the material from that location. Mr. Baskin is also pursuing other sources, including Lincoln-Mercury paint from a Canadian plant and Ford paint from Detroit. He is also looking for fordite from Harley-Davidson motorcycles to fulfill the appetite of Harley lovers.

	The color layers and patterns of polished fordite are eye-catching, and experienced cutters know how to unveil its most beautiful side (figure 2). Because it is composed of paint, the material is very light. Protection such as a dust mask is necessary during the cutting and polishing processes.

Figure 2. Different patterns may be exposed when the fordite material is cut open. The original profile of the paint slag can be kept as well. Strata and concentric color circles are some of the most spectacular patterns. On the left is a 32.36 ct (52 × 64 mm) specimen; the one on the right is 41.86 ct (28 × 73 mm). Both pieces were polished by Jason Baskin. Photo by Robert Weldon/GIA; courtesy of the Clamshell.

	Mr. Baskin noted that jewelry designers and hobbyists purchase most of his fordite, though he also sells the cut material (figure 3) through other gem dealers. Some of the knobs from the heaters and gear shifters in the old Corvettes had a piece of embedded plastic; clients have him cut Corvette fordite to replace that plastic. Pricing ranges from $20 to several hundred dollars apiece. A very rare type of fordite from 1972 with large metal flakes sold for $400 once it was cut into a 40 × 30 mm cabochon.

Figure 3. The finished pieces shown here are some of the finest fordites on the market. Photo by Orasa Weldon/GIA; courtesy of Jay’s Minerals. @chapter:21 @chapter:0 @chapter:21


# Publication Year: 2014
# Title: Assemblage of Synthetic Ruby in Calcite Matrix
# Abstract: Figure 1. This synthetic ruby was fixed in a white and cream-colored matrix and represented as natural ruby. Photo by Sutas Singbamroong, Dubai Central Laboratory.

              Recently, the Dubai Central Laboratory received a white and cream-colored rough sample for identification (figure 1). The 124.4 × 107.7 × 65.8 mm, 5917.35 ct specimen had two openings, the larger one about 25 mm long and 10 mm wide. A hexagonal red stone embedded in the matrix could be seen through these openings (figure 2). Only the prism side was visible, and the rough concealed both terminations.

	Figure 2. The synthetic ruby was embedded in a calcite matrix, seen here under incandescent light. Photo by Nazar Ahmed, Dubai Central Laboratory.
The red stone’s refractive index and specific gravity were impossible to determine, and only a very small portion was visible for obtaining other information. A spectroscope was the only option, and the stone clearly showed a ruby spectrum. It also displayed strong and medium red reactions to long- and short-wave UV radiation, respectively. Microscopic examination with fiber-optic light revealed a group of round gas bubbles and tiny fractures, but curved striae were not seen. These properties indicated a flame-fusion synthetic ruby cleverly embedded in matrix to imitate natural ruby.

Raman spectroscopy identified the matrix as calcite. Close examination indicated that the cream-colored side of the stone had been drilled to make a hole for inserting the synthetic ruby. After the drilled area was sealed with a mixture of glue and calcite powder, two openings were cut to reveal the synthetic ruby inside. Under long-wave UV radiation, the drilled area showed strong greenish blue fluorescence, while the rest of the stone was inert or exhibited a light greenish blue reaction (figure 3).

	Figure 3. Under long-wave UV radiation, the drilled area showed strong greenish blue fluorescence. Photo by Nazar Ahmed, Dubai Central Laboratory.
These types of artificial assemblages should alert traders to exercise caution when purchasing rough stones, especially in newer, less established markets. @chapter:24 @chapter:0 @chapter:24


# Publication Year: -
# Title: Jewelry Sales Show Modest Rise; Higher End Soars
# Abstract: Retail traffic was down across the board ‒ though sales were up ‒ this past holiday season. Photo by Russell Shor/GIA

Jewelry sales during the U.S. holiday season increased slightly from 2018 on average, with higher-end independent jewelers far exceeding that average, according to various surveys. Online buying surged, while foot traffic in retail stores slowed.
A MasterCard survey reported that online jewelry buying increased 9% over 2018, while overall jewelry sales were up less than 2%. The National Retail Association Federation mid-season survey found overall retail sales to be up about 2.1%, half of the higher end of the estimated 3.4% to 4.2% it had predicted.
Preliminary results from Tiffany & Co., which reported sales declines in each of the past three quarters, rebounded to show a 2% to 4% holiday sales increase in North America and 1% to 3% worldwide ‒ with a steep drop occurring in Japan. Signet Group, which includes Kay Jewelers, Zales and Jared, said it expects a 2% to 4% decline in same store sales when it announces its quarterly earnings later this month.
Some retail analysts attributed the sharp decline in foot traffic in 2019 year to an abnormally short shopping period between Thanksgiving and Christmas, saying it shifted a lot of business to the internet.
“Due to a later-than-usual Thanksgiving holiday, we saw retailers offering omnichannel sales earlier in the season, meeting consumers’ demand for the best deals across all channels and devices,” said Steve Sadove, senior adviser for MasterCard, in a press statement.
Independent jewelers in the U.S. turned in one of their best years ever, according to a recent survey in The Centurion newsletter. It found that 81% of jewelers saw increases, with more than half of that group posting hikes of 6% or more. Only 7.1% of those surveyed said they saw real declines in business and the remainder stayed even. A mid-season survey found a much higher percentage running behind last year, but a flurry of final-week business pushed most of them into positive territory.
“Although the season started slow for many upscale jewelers, the end result was well worth it, with more than 80% of respondents to The Centurion's Holiday Sales Success Index reporting sales gains over last year's already-solid season,” says Hedda Schupak, editor of The Centurion newsletter. “But jewelers in the Midwest are not feeling as much love as their peers. With the exception of a few outliers who cited specific reasons for a drop ‒ such as losing either a coveted brand or a key top-performing salesperson ‒ those jewelers reporting steep year-on-year sales declines were mainly located in the Midwest.”
One down spot in the survey: Business from millennial shoppers was down ‒ millennials accounted for 18% of jewelers’ seasonal sales compared to 25% in 2018.
JEWELRY AUCTIONS
The top auction houses Sotheby’s and Christie’s ended 2019 somewhat below the record years of the past decade, totaling an estimated $750 to $800 million for the year, with Christie’s holding the larger share at about $430 million.
Sotheby’s year-closing Dec. 12 New York sale featured a GIA-graded 7.55 ct cushion cut Type IIb, Fancy Deep grayish-blue diamond that sold for $6.6 million, 10% above its low estimate. A 20.16 ct Fancy Deep brownish-pinkish-orange diamond sold for $2.8 million, well above its estimate. The sale totaled $43 million.
At Christie’s New York auction a day later, a brooch featuring an 11.20 ct Burmese ruby surrounded by emeralds and diamonds sold for $9 million, more than double its pre-sale estimate. The brooch belonged to the Du Pont family. The sale also included a GIA-graded 3.07 ct Fancy Vivid blue diamond, Type IIb, that sold for $3.4 million and a Kashmir sapphire and diamond ring with a combined weight of 30.14 cts that brought $3 million. That sale totaled $67.5 million.
JAPANESE RETAIL
Larger jewelers in Japan, the world’s fourth largest jewelry market, are bracing for a sales hit after the government added a 2% increase to the national sales tax that had been delayed two years. In 2012, the government voted to double the consumption tax to 10% in two stages. The first stage in 2014 raised the tax to 8%, which sharply curtailed retail spending and caused the nation’s economy to fall into recession.
The nation’s economic difficulties caused the government to delay the second stage, originally scheduled for the following year, until last October, when it raised the consumption tax from 8% to 10%. The tax has begun to dampen spending on high ticket items. To reduce the economy-dulling effects of the tax, the government is offering 5% consumer rebates on purchases made to smaller retailers, including independent jewelers, by electronic payments. Some economists believe the 5% rebate will mitigate some of the negative effects on the economy.
Japan accounts for 10% of the world’s spending on luxury goods, which is dominated in Japan by international firms and large retail chains that are not eligible for the rebate program. Tiffany & Co. in Japan, for example, has already felt the effects: sales plunged 12% to 14% between Nov. 1 and Dec. 31, 2019. @chapter:32 @chapter:3 @chapter:32


# Publication Year: -
# Title: Bench Tip #14: How to Handle the Flexshaft and Handpiece
# Abstract: Flexshaft and handpiece

 Here are a few observations that can make your equipment last longer and prevent possible injury.

The flexible shaft machine, commonly called a “flexshaft,” is a combination of a motor, handpiece and the flexible shaft that connects the two. The machine is usually operated by a foot pedal. Because jewelers often use more than one handpiece during the workday, the procedure of connecting a handpiece to the flexible shaft is a common operation, but is often done incorrectly.

	The handpiece (A) fits onto the end of the flexshaft (B), but must be properly aligned.
The end of the flexible shaft is a “keyed tip” that rotates when the foot pedal is depressed. When connecting the shaft to a handpiece, it is essential to fit this keyed tip into the slot inside the cover of the handpiece. Since the slot is inside the handpiece, it is difficult to see.

	The rotating keyed tip portion of the flexible shaft (A) fits and slides into the locking mechanism of the flex shaft handle (B).
If the flexshaft tip is pushed into the handpiece without aligning the key to the slot, there is potential for equipment damage and personal injury:

		Sometimes the key will rotate and drop into the slot when the pedal is depressed, but this will eventually wear down the key.

		The shaft can also bend the connector inside the handpiece, causing it to jam and the handpiece to violently jerk if the pedal is depressed quickly. This can cause injury or damage the flexshaft or handpiece.

	If not inserted properly, the keyed tip will wear down and eventually fail.
To make sure the key and slot are properly aligned, some jewelers will look down inside the handpiece to find the orientation of the slot, then turn the handpiece as needed so the key drops in. This works, but here is a fast and simple way to make the connection:

		Slightly depress the foot pedal so the shaft is turning slowly, then insert the shaft into the handpiece and gently push.

		You will feel the key drop into the slot and can see that the connection is correct when the handpiece begins to move (rotate or hammer, depending on the handpiece).

		Now you know the key and slot are properly aligned and it is safe to snap the shaft the rest of the way into the handpiece. @chapter:28 @chapter:2 @chapter:28


# Publication Year: 2001
# Title: Summer 2001 G&G Book Reviews
# Abstract: “Ammolite 2: A Guide for Gemmologists, Jewellers and Lapidaries”
By Donna Barnson, 116 pp., illus., publ. by the author, 2000. Can$29.95

“The Dorling Kindersley Handbook of Gemstones”
By Cally Hall, with photography by Harry Taylor, 160 pp., illus., publ. by Dorling Kindersley, London, 2000. US$18.95

“Gem & Jewelry Pocket Guide”
By Renee Newman, 156 pp., illus., publ. by International Jewelry Publications, Los Angeles, 2001. US$11.95

“Nature Guide to Gemstones & Minerals of Australia.”
By Lin Sutherland and Gayle Webb, 128 pp., illus., publ. by Reed New Holland Publishers, Sydney, 2000. Aus$24.95

“The Practical Guide to Jewelry Appraising”
By Cos Altobelli, 292 pp., publ. by the American Gem Society, Las Vegas, NV, 2000. US$49.95

“Ethnic Jewelry: From Africa, Europe and Asia”
By Sibylle Jargstorf, 160 pp., illus., publ. by Schiffer Publishing Co., Atglen, PA, 2000, US$29.95.

“Costume Jewelers: The Golden Age of Design, 3rd Ed”
By Joanne Dubbs Ball, 205 pp., illus., publ. by Schiffer Publishing Co., Atglen, PA, 2000, US$39.95

To view the full section, download the PDF above. @chapter:33 @chapter:2 @chapter:33


# Publication Year: 2016
# Title: Quarterly Crystal: Quartz with Axinite
# Abstract: Figure 1. Two examples of quartz with inclusions of ferroaxinite from the New Melones Dam in Calaveras County, California. The larger specimen measures 65.28 mm tall. Photo by Kevin Schumacher.

In their September-October 1982 Mineralogical Record article, D. Pohl et al. described a discovery of ferroaxinite from New Melones Dam in Calaveras County, California. There was a very brief mention of ferroaxinite inclusions in quartz, but no illustrations of the inclusions were provided. Recent exploration of the Calaveras County locality by one of the authors (JM) led to the discovery of a large pocket that produced some beautiful axinite and quartz specimens (figure 1) containing bladed inclusions of ferroaxinite.

This new mineralized pocket was situated on the edge of a ledge and had a different geological appearance than the surrounding area. Successive layers within the pocket, 6–12 cm in thickness, were composed of metagabbro and crushed coarse rock crystal quartz that contained well-developed single quartz crystals measuring up to 9 cm in length and 6 cm in diameter. These crystals displayed both long and short columnar habits. Also found within them were crushed coarse crystalline axinite and mats of small epidote needles. Cracks in the crystals allowed quartz-forming fluids to seep through and crystallize on the surface of the metagabbro, often surrounding both the epidote matting and a mixed layer consisting of chlorite/axinite/epidote.

The large pocket, measuring approximately 7 feet deep, 4 feet wide, and 6 feet long, produced almost 2,000 pounds of quartz. The specimens ranged from translucent to extremely clear and varied in size from 1 to 18 cm. Some of them contained axinite or chlorite phantoms as well as full and partial inclusions of bladed axinite floater crystals. This huge pocket also produced several spectacular plates of axinite, with individual crystals measuring up to 8 cm long, along with floater crystals of similar dimensions.

The axinite inclusions themselves displayed the typical bladed habit expected for this mineral. When examined with polarized light, they also showed pronounced pleochroism, from a light brown (figure 2, left) to a more intense pinkish purple (figure 2, right). This represents the first visual record of axinite inclusions in quartz published in the gemological and mineralogical literature.

Figure 2. With plane-polarized light, the axinite inclusions in quartz show very distinct pleochroism. Both of these images were taken with the polarizer rotated at approximately 90 degrees from each other. Photomicrographs by John I. Koivula; field of view 9.0 mm. @chapter:8 @chapter:0 @chapter:8


# Publication Year: 2018
# Title: Large Pargasite Inclusion in Kashmir Sapphire
# Abstract: Figure 1. This 14.06 ct octagonal blue Kashmir sapphire exhibits large, eye-visible inclusions of prismatic pargasite. Photo by Towfiq Ahmed.

Kashmir sapphires are known to have occurred in kaolinized plagioclase feldspar pegmatites, found as pockets between metamorphic stratified beds/cliffs of the Himalayan Zanskar Range. These sapphires captured many cognate mineral inclusions—such as pargasite, plagioclase feldspar, tourmaline, and zircon—which demarcate the pockets against the country rock (E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Vol. 3, Opinio Publishers, Basel, Switzerland, 2008, p. 194).
Pargasite mineral inclusions (prismatic or as long, fine needles) in blue sapphire are regarded as a strong indicator of Kashmir origin. (R. Schwieger, “Diagnostic features and heat treatment of Kashmir sapphires,” Winter 1990 G&G, pp. 267–280).
Recently, a 14.06 ct octagonal-cut blue sapphire (figure 1) submitted to GIA’s Carlsbad laboratory for origin determination was of particular interest for its several unusually large, eye-visible pargasite crystal inclusions. Standard gemological properties confirmed the host sapphire’s identity, and advanced analytical testing specified its metamorphic geological origin.
Microscopic examination revealed an inclusion scene reminiscent of “new Kashmir,” a term referring to Kashmir sapphires that have come into the market since the 2000s. The blue sapphire featured several negative crystals, black graphite inclusions, unidentified rounded and needle-shaped colorless crystal inclusions (probably slender zircon rods or pargasite), reflective thin films, and fluid fingerprints.
Classic Kashmir sapphire features were also observed, such as “milky” turbid whitish broad bands, clouds, a parallel chromium-enriched zone (which glows red under long-wave UV illumination), ladder-like/antenna-like stringers, and snowflake-like inclusions.

Figure 2. A large prismatic pargasite mineral inclusion. Photo by Jonathan Muyal; field of view 7.19 mm.

Figure 3. Unoriented Raman spectra with 514 nm excitation confirmed the pargasite mineral inclusion identity (blue spectrum), using the RRUFF database as a reference (red spectrum).
The main inclusion features, the pargasite crystals (figure 2), were transparent with a brownish green bodycolor. Many of them were doubly terminated with a flat, columnar prismatic morphology with striations along their length, surrounded by halo- or rosette-like thin reflective films. The pargasite crystal’s surface pits and altered appearance suggested that these pargasite crystals were protogenetic inclusions present in the pegmatitic growth environment before the sapphire began to form. Raman microspectrometry analysis (figure 3) confirmed the identity of several crystal inclusions as pargasite.
The absence of 3309 peak series in IR spectroscopy and the microscopic observation of unaltered internal features supported an unheated call. The classic metamorphic UV-Vis absorption spectra, the metamorphic-type low-Fe chemistry data collected with Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS), and the observed inclusion scene supported a Kashmir origin conclusion. The issued GIA report identified the stone as a natural sapphire from Kashmir with no indications of heating.
Pargasite was once thought to be unique to Kashmir until it was found in sapphires from other countries. Nonetheless, pargasite inclusions are a strong indicator of Kashmir origin. With the support of advanced analytical instrumentation (UV-Vis and LA-ICP-MS) in addition to careful examination of the overall internal features (milky bands, ladder-like stringers, and snowflakes), the presence of pargasite inclusions can conclusively determine a Kashmir origin. @chapter:26 @chapter:0 @chapter:26


# Publication Year: 2021
# Title: Pink Aventurine Quartz with Alurgite Inclusions
# Abstract: Figure 1. This bangle was submitted as “strawberry quartz” to TULAB. Photo by Shu-Hong Lin.
“Strawberry quartz” is not a strictly defined term in gemology but generally recognized in the market as single-crystal quartz with numerous striped or flaky hematite inclusions, which cause a pink to red overall appearance (D.I. Belakovskiy, “New acquisitions of the Fersman Mineralogical Museum, Russian Academy of Sciences (1997–2001),” New Data on Minerals, Vol. 38, 2003, pp. 101–112). Strawberry quartzes, due to limited mine production and rough sizes, are usually cut into beads, cabochons, or faceted stones or used for small carvings, all very popular products in the Taiwanese market.
Recently, a bangle was submitted for identification service to the Taiwan Union Lab of Gem Research (TULAB) as strawberry quartz (figure 1). The bangle had a brownish pink color in appearance and had a number of orangy pink to orangy red flaky crystals visible under the microscope. It had a refractive index of 1.54 and a specific gravity of 2.60. The material was found to be crystal aggregates through a polariscope and showed aventurescence under penlight.

Figure 2. Raman spectra comparisons between the red inclusions and those of quartz and muscovite from the RRUFF database identified the bangle as aventurine quartz with orangy red muscovite inclusions. The stacked spectra are baseline-corrected and normalized.
In order to identify this material and its inclusions, the bangle was analyzed with micro-Raman spectrometry and the RRUFF database. It was found that the material was actually polycrystalline quartz and the red flaky inclusions were muscovite (KAl2(Si3Al)O10(OH,F)2) (figure 2). SEM-EDS analysis of the inclusions exposed to the surface further verified them as iron-bearing muscovite; however, EDXRF analysis revealed trace amounts of manganese in addition to iron. In other words, this bangle should be defined as brownish pink aventurine quartz with pink to red muscovite inclusions.

Figure 3. Microscopic images of the red striped and irregular flaky hematite in strawberry quartz (left) and the orangy red muscovite (alurgite) inclusions in the pink aventurine quartz sample (right). Photomicrograph by Shu-Hong Lin; field of view 1.26 mm.
In comparison to those strawberry quartz with hematite inclusions, the red muscovite showed slight differences under the microscope. Hematite inclusions in strawberry quartz are usually striped, hexagonal, or irregular flaky crystals with medium to very dark red color under the microscope (figure 3, left); however, the red muscovite inclusions in the sample were mostly rounded flaky crystals with medium light to medium orangy red color (figure 3, right).

Figure 4. The visible light absorption spectrum of the pink aventurine quartz was compared to the reference spectra of mica (Mineral Spectroscopy Server of Caltech); results revealed that the visible light absorption spectra were consistent with that of alurgite. The overlapped spectra are normalized.
Moreover, the visible light absorption spectra of the bangle were analyzed and compared to those of mica on the Mineral Spectroscopy Server of Caltech. The pink aventurine quartz presented absorption peaks at 445, 454, 515, and 548 nm (figure 4), consistent with the spectrum of alurgite (GRR727, Mineral Spectroscopy Server of Caltech), which is a reddish purple variety of muscovite.
Since “strawberry quartz” is not a strictly defined marketing name, consumers should notice that there are actually different types of quartz with various inclusions sold with the same trade name. As an atypical strawberry quartz material, pink aventurine quartz with alurgite can be distinguished with hematite-included strawberry quartz through the methods of polariscope, microscope, and micro-Raman spectroscopy. @chapter:15 @chapter:0 @chapter:15


# Publication Year: 2004
# Title: Gem Treatment Disclosure and U.S. Law
# Abstract: In recent years, the obligation to fully disclose all gem treatments has changed from a mere ethical responsibility to a legal one. The U.S. Federal Trade Commission Guides for the gem and jewelry trade, which were fairly simple rules in the early 20th century, now require disclosure of any treatment to a gem material that substantially affects its value. In addition, all state deceptive trade practice regulations in the U.S. require that vendors not mislead customers as to the treatment status of gems they sell. Finally, vendors should also be aware that insufficient disclosure can subject them to substantial civil liability for fraud by nondisclosure. Several case studies demonstrate the serious risks involved in not complying with this body of rules and regulations. Suggestions for avoiding legal problems are provided.

	DATA DEPOSITORY

Appendix A: Excerpts from the FTC Guides
Capsule Descriptions of Cited Cases
U.S. State Laws Governing Deceptive Trade Practices and Gem Disclosure Obligations
	Submitted by Thomas W. Overton
	Summer 2004 @chapter:49 @chapter:3 @chapter:49


# Publication Year: 1986
# Title: Summer 1986 G&G Book Reviews
# Abstract: “Birthday Book of Gems”
By Harold and Erica Van Pelt, 128 pp., illus., publ. by Van Pelt Photographers, L. A., CA, 1986.
US$8.95

“The New World of Gold”
By Timothy Green, 290 pp., paperback, publ. by Walker and Co., New York, NY, 1984 (rev.). US$12.95

“Diamond, Ruby, Emerald, and Sapphire Facets”
By Gary Grelick, 56 pp., illus., privately published, 1985. US$5.00

“Art Nouveau Jewelry”
By Vivienne Becker, 240 pp., illus., publ. by E. P. Button, New York, NY, 1985. US$50.00

“Reviews in Mineralogy Volume 12: Fluid Inclusions”
By Edwin Roedder, 644 pp., illus., pub. by the Mineralogical Society of America, Washington, DC, 1984. US$15.00

To view the full section, download the PDF above. @chapter:23 @chapter:2 @chapter:23


# Publication Year: 2019
# Title: Condor Agate from Argentina
# Abstract: Core of a “Condor” agate containing faint hemispheres of fibrous, white chalcedony. Photomicrograph by Tyler Smith; field of view 14.52 mm.

“Condor” agates from the Mendoza region of Argentina are sought after by collectors for their vibrant colors and sharp banding. This variety of agate is named after the impressive Andean condor, which calls this mountainous region home. One such stone (see above) was recently examined for photomicrography. It displayed intense orange and yellow bands, likely colored by fine hematitic and limonitic concentrations. The banding ended abruptly at an opaque gray mineral interface that demarcated the transparent core. Contained within this lake were ghostly oolitic concretions, some of which enclosed their own hematite particles. Chalcedony is available in a dizzying selection of varieties and is a constant source of inspiring specimens. @chapter:8 @chapter:0 @chapter:8


# Publication Year: -
# Title: Diamond Quality Factors
# Abstract: Diamond is available in a range of sizes and qualities to fit every consumer's tastes.

	One of the first things most people learn about diamonds is that not all diamonds are created equal. In fact, every diamond is unique. Diamonds come in many sizes, shapes, colors, and with various internal characteristics.

	All polished diamonds are valuable. That value is based on a combination of factors. Rarity is one of those factors. Diamonds with certain qualities are more rare—and more valuable—than diamonds that lack them.

	Jewelry professionals use a systematic way to evaluate and discuss these factors. Otherwise, there would be no way to compare one diamond to another. And there would be no way to evaluate and discuss the qualities of an individual diamond. Diamond professionals use the grading system developed by GIA in the 1950s, which established the use of four important factors to describe and classify diamonds: Clarity, Color, Cut, and Carat Weight.

	Diamonds can be fashioned into a variety of shapes and still be beautiful.

	These are known as the 4Cs. When used together, they describe the quality of a finished diamond. The value of a finished diamond is based on this combination.

	A diamond’s value is often affected by the rarity of one or more of the 4Cs. Colorless diamonds are scarce—most diamonds have tints of yellow or brown. So a colorless diamond rates higher on the color grading scale than a diamond that is light yellow. Value and rarity are related: In this case a colorless diamond is more rare and more valuable than one with a slight yellow color. The same relationship between rarity and value exists for clarity, cut, and carat weight.

	The 4Cs describe the individual qualities of a diamond, and the value of an individual diamond is based on these qualities. The terms that people use to discuss the 4Cs have become part of an international language that jewelry professionals can use to describe and evaluate individual diamonds.

	Today, the descriptions of each of the 4Cs are more precise than those applied to almost any other consumer product. And they have a long history. Three of them—color, clarity, and carat weight—were the basis for the first diamond grading system established in India over 2,000 years ago.

Color

	Subtle differences in color can dramatically affect diamond value. Two diamonds of the same clarity, weight, and cut can differ in value based on color alone. Even the slightest hint of color can make a dramatic difference in value.

	This emerald cut diamond is colorless and is a D color grade. – Courtesy Lazare Kaplan Diamonds

	In the normal color range, the closer a diamond gets to colorless, the higher its per-carat price. There’s an especially large leap in the price of a colorless diamond, which is extremely rare.

	Diamonds come in many colors. Diamonds that range from colorless to light yellow and brown fall within the normal color range. Within that range, colorless diamonds are the most rare, so they’re the most valuable. They set the standard for grading and pricing other diamonds in the normal color range.

	These diamonds—graded E, K, and Z—represent diamond colors near the top, middle, and bottom of the GIA Color Scale. - © GIA & Tino Hammid

	At the GIA Laboratory, diamonds are color graded under controlled conditions by comparing them to round brilliant diamonds of known color, called masterstones.

	To eliminate the guesswork from grading a diamond’s color, graders compare it to masterstones that represent known colors in the GIA D-to-Z scale. - © GIA & Tino Hammid

	The GIA D-to-Z scale is the industry standard for color-grading diamonds. Each letter represents a range of color based on a diamond’s tone and saturation.

	Many diamonds emit a visible light called fluorescence when they’re exposed to ultraviolet (UV) radiation. Although invisible to the human eye, UV radiation is everywhere. Sunlight contains it. Fluorescent lights emit it, too. Under the right conditions, you can see fluorescence in about 35 percent of gem diamonds.

	Blue is the most common fluorescent color in gem-quality diamonds. In rare instances, fluorescence can be white, yellow, orange, or many other colors.

	Strong blue fluorescence can make a light yellow diamond look closer to colorless in sunlight. Blue and yellow are color opposites and tend to cancel each other out, so blue fluorescence masks the yellow color. If the fluorescence is too strong it can make the stone look cloudy or “oily,” which can lower the value of the diamond.

Clarity

	Few things in nature are absolutely perfect. This is as true of diamonds as anything else. Diamonds have internal features, called inclusions, and surface irregularities, called blemishes. Together, they’re called clarity characteristics. Clarity is the relative absence of inclusions and blemishes.

	Among other things, blemishes include scratches and nicks on a diamond’s surface. Inclusions are generally on the inside, and some might break the surface of the stone. Sometimes, tiny diamond or other mineral crystals are trapped inside a diamond when it forms. Depending on where they’re located, they might remain after the stone has been cut and polished, and they can affect a diamond’s appearance.

	Clarity characteristics might have a negative influence on a diamond’s value, but they can have positive effects as well. For one thing, they help gemologists separate diamond from imitations. (This is easier with included diamonds than with flawless ones.) And because no two diamonds have exactly the same inclusions, they can help identify individual stones. They can also provide scientists with valuable information about how diamonds form.

	No two diamonds have exactly the same clarity characteristics in exactly the same locations. This fact helps gemologists identify individual diamonds.

	Like the rest of the 4Cs, clarity’s influence on value is directly related to the concept of rarity. Flawless is the top grade in the GIA Clarity Grading System. Diamonds graded Flawless don’t have visible inclusions or blemishes when examined under 10-power (10X) magnification by a skilled and experienced grader.

	As clarity increases, and if all other value factors are equal, diamond price per carat also increases.

	Flawless diamonds are very rare—so rare, in fact, that it’s possible to spend a lifetime in the jewelry industry without ever seeing one, and they command top prices.

	At the other end of the scale are diamonds with inclusions that can be easily seen by the unaided eye. Between the two extremes are diamonds with inclusions visible only under 10X magnification. Stones in the middle range make up the bulk of the retail market.

	There are 11 clarity grades in the GIA clarity grading system. They are Flawless, Internally Flawless, two categories of Very, Very Slightly Included, two categories of Slightly Included, and three categories of Included.
	The effect of a clarity characteristic on the clarity grade is based on its size, number, position, nature, and color or relief.

	The GIA clarity scale includes eleven diamond clarity grades. The scale narrows at the top because there are very few diamonds in the higher clarity grades.

	Sometimes, one factor makes more difference to the clarity grade than the others. But it’s not always the same one. The relative importance of each factor varies from diamond to diamond. For example, an inclusion off to the side of a stone would have less impact on clarity than the same size inclusion located directly under the table. In this case, the position is probably the determining factor.

	A clarity characteristic's effect on a diamond's clarity grade is determined by five factors: size, number, position, nature, and color or relief. - Gary Roskin GG, FGA

	Occasionally, if an inclusion has the potential to cause damage to a stone, it can affect the grade. But this is rare, and usually applies only to Included (“I”) diamonds.

	Diamond professionals use a set of terms that originally included very very slightly imperfect, very slightly imperfect, slightly imperfect, and imperfect. In recent years, the term imperfect has been replaced with included. (GIA uses included in its clarity grading system.)

	These terms were shortened to the initials VVS, VS, SI, and I. The abbreviations eventually gained acceptance throughout the international diamond community. Their use is now widespread regardless of how the words they stand for translate into various languages. Very may translate to tres in French, for instance, but in France a very slightly included diamond is still a VS. Even a country like Russia, with a completely different alphabet, uses the same abbreviations.

Cut

	A beautifully finished diamond is dazzling, with every facet displaying the craftsman’s skill and care. When a diamond interacts with light, every angle and every facet affects the amount of light returned to the eye. This is what gives it its face-up appearance.

	In efforts to differentiate themselves, and because of increasing demand for precision in cutting, many manufacturers fashioned diamonds to exacting standards throughout the decade. Note the precise arrow pattern in this 1.54 ct diamond.

	A diamond’s proportions determine how light performs when it enters the diamond. If light enters through the crown and goes out through the pavilion, the diamond will look dark and unattractive.  Diamonds with different proportions and good polish make better use of the light, and will be bright, colorful, and scintillating.

	A well-cut diamond displays the beauty consumers expect to see in a diamond.

	A beautiful diamond looks the way it does because of three optical effects: white light reflections called brightness, flashes of color called fire, and areas of light and dark called scintillation. Pattern is the relative size, arrangement, and contrast of bright and dark areas that result from a diamond’s internal and external reflections. There must be enough contrast between the bright and dark areas to give the pattern a crisp, sharp look.

	The diamond industry has long known that some proportion combinations make light perform better than others. In recent years, however, scientists and researchers in GIA’s Research Department and the GIA Laboratory have shown that there are many variations and combinations of proportions that will maximize brilliance and fire in round brilliant cut diamonds.

	As a general rule, the higher the cut grade, the brighter the diamond. Under fluorescent lighting, these diamonds (left to right) display high, moderate, and low brightness.
	The term “cut” also can describe a fashioned diamond’s shape. Shapes other than the standard round brilliant are called fancy cuts. They’re sometimes called fancy shapes or fancies. Fancy shapes also have names of their own, based on their shapes. The best known are the marquise, princess, pear, oval, heart, and emerald cut.

	Fancy-shape diamonds, along with the classic round diamonds, are popular choices for today’s jewelry consumer. Courtesy Lazare Kaplan Diamonds

Carat Weight

	Many goods are sold by weight—by the kilogram, ounce, pound, or ton. Even people who have never bought a diamond are used to the idea that weight and price are related. They understand that a larger diamond is probably more valuable than a smaller one. But there are two things that often surprise people when they start learning about diamonds and carat weight.

	The first is the precision with which diamonds are weighed. Diamond weights are stated in metric carats, abbreviated “ct.” One metric carat is two-tenths (0.2) of a gram—just over seven thousandths (0.007) of an ounce. One ounce contains almost 142 carats. A small paper clip weighs about a carat.

	The metric carat is divided into 100 points. A point is one hundredth of a carat.

	Diamonds are weighed to a thousandth (0.001) of a carat and then rounded to the nearest hundredth, or point. Fractions of a carat can mean price differences of hundreds—even thousands—of dollars, depending on diamond quality.

	Over a carat, diamond weights are usually expressed in carats and decimals. A 1.03-carat stone, for example, would be described as “one point oh three carats,” or “one oh three.” Weights for diamonds that weigh under a carat are usually stated in points. A diamond that weighs 0.83 carat is said to weigh “eighty-three points,” or called an “eighty-three pointer.”

	Large high quality diamonds are rare and valuable gems. This diamond weighs a remarkable 100.20 carats and is internally flawless. - © GIA and Harold & Erica Van Pelt, courtesy The Steinmetz Group

	The relationship between rarity, weight, and value can be surprising. People know that a pound of sugar costs twice as much as a half-pound of sugar. But diamonds aren’t a commodity like sugar. Their price depends on a number of variables—weight is just one of them. So it’s not always easy to understand, or explain, why a 1-carat diamond is worth, say, $6,000, while a 2-carat diamond of similar quality might be worth $15,000.

	It’s really a simple concept: Large diamonds are more rare than small diamonds. The more scarce something is, the more it is worth. So a larger stone doesn’t just cost more. It also costs more per carat. A 1-carat diamond weighs the same as four 0.25-carat diamonds. But even if all the other quality factors are equal, the larger diamond is worth much more than the sum of the four smaller diamonds.

	Carat weight can also be symbolic. While the visual difference between a 0.98-carat diamond and a 1.01-carat diamond is negligible, many people will opt for the larger stone—even at a much higher price. Some weights are considered “magic sizes”: half carat, three-quarter carat, one carat, etc. There’s not much difference in their weights, but if both are D-color round brilliants with identical clarity and cut, the size makes all the difference. They really don’t look much different, but if a consumer’s heart is set on the one-carat size, the difference is enormous. The fact that the second stone is slightly over the “magic” one-carat size can give it as much as a 20 percent difference in price with only a 6-point difference in weight.

	This oval shape diamond weighs 1.01 carats and made the 1.00 carat magic size range. When diamonds reach the so called magic sizes the value per carat increases. – Courtesy Lazare Kaplan Diamonds

	Don’t confuse the term carat with karat. Karat is a unit of measure used to describe how much pure gold there is in an alloy. @chapter:41 @chapter:1 @chapter:41


# Publication Year: 2017
# Title: Exhibition Review: Gemstone Carvings: The Masterworks of Harold Van Pelt
# Abstract: Figure 1. Faceted quartz egg. © 2010 Harold and Erica Van Pelt.

World renowned for their gem photography, Harold and Erica Van Pelt are no strangers to beauty, accuracy, and integrity. Harold Van Pelt has applied the same principles to gemstone carving for more than 40 years. Thirty-five of his pieces, including the faceted quartz egg with aquamarine pedestal seen in figure 1, have returned to Santa Ana’s Bowers Museum, where they were first exhibited in 2010. The exhibition, called Gemstone Carvings: The Masterworks of Harold Van Pelt, is located in the PIMCO Foundation Gallery of the Dorothy and Donald Kennedy Wing.

The precision of Van Pelt’s work is apparent even at the entrance of the gallery. Displayed here are three carvings, including a stunning moss agate bowl and an agate rhyton shaped as a ram’s head (figure 2). Along the wall, glass cases show 26 of Van Pelt’s carvings. Some are accompanied by rough crystals of the material used in the carving; a striking amethyst cup with 24 flutes carved into the base and body is placed alongside two rough amethyst crystals (figure 3). A candlestick carved from Australian chrysoprase is shown with a piece of rough that reveals the blue-green gem emerging from the gray rock.

Figure 2. Agate rhyton. © 2010 Harold and Erica Van Pelt.

Figure 3. Amethyst cup with amethyst crystals. © 2010 Harold and Erica Van Pelt.
Quartz eggs are prominent throughout the exhibition, along with instructions and photographs along one wall detailing how to create these pieces. In “Suspension,” one of these hollow eggs is supported by gold over a mahogany obsidian base. The eggs are by no means the only showcase for Van Pelt’s talents. A seemingly delicate quartz container suspended from two pillars of rutilated quartz, called “Balancing Act” (figure 4) shows how much strength the material actually possesses. While quartz is featured in many pieces, other materials used in combination include petrified wood and tourmaline, the latter in a stunning vase.

Figure 4. “Balancing Act.” © 2010 Harold and Erica Van Pelt.
Of particular note are carvings that represent the human anatomy, such as an exquisite reproduction of a skeleton’s hand in white chalcedony. The material was chosen for its resemblance to the color of human bones. Both sides of the piece are visible, and each bone in the hand took months to complete, showing Van Pelt’s attention to even the smallest details of each carving. Similarly, a life-sized recreation of both sides of Erica Van Pelt’s hand in rutilated quartz (figure 5) even captures the shape of her fingernails. A hollow skull carved from quartz with rare izoklakeite inclusions features a jaw that opens and closes (figure 6). Created from a 250 lb. crystal, the finished piece weighs 6.5 lbs. and is named “Izok.”

Figure 5. Rutile hand. © 2010 Harold and Erica Van Pelt.

Figure 6. “Izok.” © 2010 Harold and Erica Van Pelt.
While the exhibition is a must for gem aficionados, Gemstone Carvings is worth a visit for anyone who appreciates beauty and artistic skill.

Gemstone Carvings: The Masterworks of Harold Van Pelt is on exhibit at the Bowers Museum indefinitely. General admission is $13 on weekdays, $15 on weekends. Students and seniors are $10 on weekdays and $12 on weekends; children under 12 are free every day. The Bowers Museum is open Tuesday–Sunday from 10:00 a.m. to 4:00 p.m.; it is closed on Mondays, Thanksgiving, Christmas Day, New Year’s Day, and July 4th. @chapter:28 @chapter:2 @chapter:28


# Publication Year: 1992
# Title: Spring 1992 G&G Book Reviews
# Abstract: “Cameos Old and New”
By Anna M. Miller, 216 pp., illus., publ. by Van Nostrand Reinhold, New York, 1991. US$39.95

“Basic Wax Modeling: An Adventure in Creativity”
By Hiroshi Tsuyuki, 106 pp., illus., publ. by Matsubara-Kashiwa Books, Japan, 1990. US$25.00

“The Encyclopedia of Gemstones and Minerals”
By Martin Holden, 303 pp., illus., publ. by Michael Priedman Publishing Group, 1991. US$45.00

“Ancestral Jewels”
By Diana Scarisbrick, 191 pp., illus., publ. by Vendome Press, New York, 1991. US$37.50

To view the full section, download the PDF above. @chapter:31 @chapter:2 @chapter:31


# Publication Year: 2023
# Title: “Sun Spangle” in Amber
# Abstract: A “sun spangle” created in amber as a result of rapid cooling. Photomicrograph by Aamir Sayed; field of view 1.5 mm.
Fractures often diminish a gemstone’s beauty and appeal. To reduce the detrimental effects caused by fractures and to enhance appearance, many gemstones undergo treatment. But not all fractures are undesirable. One such example is the circular stress fracture in amber (see above) recently encountered by the author.
Minute gas bubbles in amber cause cloudiness, which can be removed by heating the material. If the amber cools too rapidly, it may develop internal circular stress cracks called “sun spangles.” Sun spangles are considered desirable and are often created deliberately, such as the attractive example shown here. The concept can be likened to the Japanese art of kintsukuroi or kintsugi, in which broken pottery is repaired with gold undisguised, embracing the piece as more beautiful for having been broken. @chapter:16 @chapter:0 @chapter:16


# Publication Year: 1997
# Title: Modern Diamond Cutting and Polishing
# Abstract: This article examines the sophisticated techniques and equipment currently used to fashion a polished gem from a rough diamond. The basic manufacturing techniques— sawing, bruting, blocking, and polishing—are described with regard to the decisions that must be made to obtain the greatest value from a specific piece of rough. Over the last 25 years, the diamond-cutting industry worldwide has been revolutionized by sophisticated instruments for marking, laser sawing machines, laser kerfing machines, automatic bruting machines and laser bruting systems, automatic centering systems, and automatic polishing machines. @chapter:41 @chapter:1 @chapter:41


# Publication Year: 2015
# Title: Beryllium-Diffused and Lead Glass–Filled Orange Sapphire
# Abstract: Figure 1. This 4.25 ct orange sapphire was submitted for a colored stone identification report. Photo by Robison McMurtry.

              The Carlsbad laboratory recently received a 4.25 ct transparent orange oval mixed-cut stone (figure 1) for a colored stone identification report. Standard gemological testing established the following properties: RI—1.762 to 1.770; birefringence—0.008; optic sign—uniaxial negative; pleochroism—strong orange and very light yellow; and SG—3.98. All of these properties are consistent with both natural and synthetic sapphire.

Under magnification, the most distinctive internal characteristic was the presence of numerous fractures partially healed by glassy flux-like droplets. Some had a wispy veil and fingerprint-like appearance. One fracture with large healed areas showed a strong flash effect, which appeared greenish blue under brightfield illumination (figure 2, left) and orange-red under darkfield illumination (figure 2, center) when rotating the stone to another direction. Under diffused lighting, the outline of the large partially healed areas stood out clearly (figure 2, right). The flash effect indicates that the fracture was healed using a material with a high refractive index, possibly lead glass (S. F. McClure et al., “Identification and durability of lead glass–filled rubies,” Spring 2006 G&G, pp. 22–34).

Figure 2. Under brightfield illumination, the large healed fracture showed a greenish blue flash effect (left). Under darkfield illumination, the same fracture showed an orange-red flash effect (center). Under diffused lighting (right), the outline of the fracture became distinct. Photos by Ziyin Sun; field of view 3.45 mm.
Heat-treated sapphires submitted to GIA are routinely checked using advanced analytical tools. Energy-dispersive X-ray fluorescence (EDXRF) analysis was performed on the table facet where the large healed fracture with flash effect was located. The presence of Pb was clearly detected, indicating the filler was lead glass. Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) was used to confirm the stone’s natural trace-element chemistry and detect the beryllium-diffusion treatment. Beryllium was present in all laser ablation spots, but analysis of the partially healed fractures revealed high Pb content in addition to Be. In one spot, both high Be (156 ppmw) and Pb (23,300 ppmw) were present, which provided some possible insight into the treatment process.

Corundum selected for lead-glass filling usually goes through a two-step process. The material is heated at temperatures from 900° to 1400°C to remove the impurities in fissures, followed by another heating at 900° to 1000°C in the presence of a lead-glass mixture to fill the fractures (V. Pardieu, “Lead glass filled/repaired rubies,” Asian Institute of Gemological Sciences Gem Testing Laboratory, 2005, http://fieldgemology.org/Ruby_lead_glass_treatment). Beryllium diffusion requires a temperature range from 1800° to 1850°C, close to corundum’s melting temperature of 2045°C, which requires a special resistance furnace (J. L. Emmett et al., “Beryllium diffusion of ruby and sapphire,” Summer 2003 G&G, pp. 84–135). If the stone had been filled first, the lead-glass filler likely would have melted and flowed out of the fractures during the beryllium diffusion treatment (McClure et al., 2006). It is unlikely that the Be diffusion and lead glass–filling treatments occurred simultaneously. Such a process has not been documented and would likely pose technical challenges, partly because the relatively high temperature required for the beryllium diffusion treatment would have outgassed much of the lead and caused serious toxic gas exposure.

The best possible explanation is that the stone was beryllium diffused at a high temperature to improve its color before being treated with lead glass at a lower temperature to improve its clarity. If some residue of the original Be treatment was left in a fracture that was later filled with lead glass, this could explain the correlation of high Be and high Pb in one of our LA-ICP-MS analyses.

GIA’s laboratories have identified numerous beryllium-diffused or lead glass–filled stones. That the two treatments were applied in a single sapphire is very rare. It is the first time such a stone has been examined by the GIA laboratory. @chapter:19 @chapter:1 @chapter:19


# Publication Year: 2016
# Title: Olivine in Oregon Labradorite
# Abstract: Figure 1. This octagonal step-cut labradorite (left) was faceted with an extra-large girdle and a simple faceting pattern to showcase the olivine inclusion trapped inside (right). Photos by Kevin Schumacher.

	Gem-quality labradorite from Oregon is typically prized for its red, orange, and green colors, as well as the tiny exsolution platelets of copper that create the phenomenon of aventurescence. Other notable inclusions can also be found in this gemstone from time to time, such as the olivine inclusion in the stone provided by Ken Lack of Gem Net LLC in Grants Pass, Oregon (figure 1). These rare inclusions typically display a greenish yellow bodycolor and compression cracks, indicating a significant amount of strain between the feldspar host and the olivine guest (figure 2; see E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Vol. 2, Opinio Verlag, Basel, Switzerland, 2005, pp. 419, 422). In this example, the stone was reported to have cracked during cutting, presumably due to the strain. This labradorite was cut to showcase the inclusion, making it easy to view from multiple angles.

Figure 2. The olivine inclusion was photographed in an immersion liquid, which wicked along surface-reaching cracks and partially eliminated the reflective interface, allowing better observation inside the olivine. Photomicrograph by Nathan Renfro; field of view 3.83 mm.

	Olivine inclusions in labradorite feldspar typically indicate an Oregon origin—if one is lucky enough to find such a rare internal feature. @chapter:2 @chapter:0 @chapter:2


# Publication Year: 2010
# Title: Play-of-Color Opal from Wegel Tena, Wollo Province, Ethiopia
# Abstract: A new opal deposit was discovered in 2008 near the village of Wegel Tena, in volcanic rocks of Ethiopia’s Wollo Province. Unlike previous Ethiopian opals, the new material is mostly white, with some brown opal, fire opal, and colorless “crystal” opal. Some of it resembles Australian and Brazilian sedimentary opals, with play-of-color that is often very vivid. However, its properties are consistent with those of opal-CT and most volcanic opals. Inclusions consist of pyrite, bariummanganese oxides, and native carbon. Some samples show “digit patterns”: interpenetrating playof-color and common opal, resembling fingers. The opaque-to-translucent Wegel Tena opals become transparent when soaked in water, showing a remarkable hydrophane character. White opals from this deposit contain an elevated Ba content, which has not been reported so far in opal-CT. The fire and crystal opals are prone to breakage, while the white, opaque-to-translucent opals are remarkably durable. The proportion of gem-quality material in the Wegel Tena deposit seems unusually high, and 1,500 kg have already been extracted using rudimentary mining techniques. The deposit may extend over several kilometers and could become a major source of gem-quality opal.

	DATA DEPOSITORY

Details of the LA-ICP-MS Analytical Conditions
Chemical Composition of Opals from Wegel Tena, Ethiopia, Measured by LA-ICP-MS
	July 31, 2010 @chapter:48 @chapter:0 @chapter:48


# Publication Year: -
# Title: Anahí’s “New” Ametrine
# Abstract: Figure 1. At Bolivia’s Anahí mine, a worker removes an ore car loaded with quartz-bearing material that will then be washed and presorted. Photo by R. Weldon.

              The Anahí mine in southeastern Bolivia, near the border with Brazil, has enjoyed consistent production since coming under private control in 1990. The mine is best known for its ametrine (amethyst-citrine), a quartz variety that exhibits two principal colors, purple and yellow (see P. M. Vasconcelos et al., “The Anahí ametrine mine, Bolivia,” Spring 1994 G&G, pp. 4–23). Bolivia is the world’s only commercial source of this gem. Mine owner Ramiro Rivero has transformed operations in recent years to better control production, cutting, jewelry manufacturing, and retail activities, establishing a clear mine-to-market chain of custody for his product (see Winter 2001 GNI, pp. 334–335).

In August 2008, GIA staff members visited Anahí to videotape and report on the mine-to-market operations. The Anahí mine presently employs 74 workers and is active in five tunnels (e.g., figures 1 and 2). The company has also started to process the tailings piles to recover material that is now popular in the market, such as pale amethyst (called anahíta in Bolivia). Taking advantage of abundant groundwater supplies, workers wash the ore on location and then presort it before transport to Minerales y Metales del Oriente, Mr. Rivero’s manufacturing arm in the Bolivian city of Santa Cruz.

Figure 2. This tunnel at the Anahí mine exhibits the richness of the quartz deposit. Photo by Robert Weldon/GIA.

Production at the Anahí mine is lower than it was a decade ago, but Mr. Rivero maintains that is because greater efficiencies in mining, sorting, and cutting have reduced the amount of rough needed for the value-added operations.

Nevertheless, the mine still produces some 2,500–3,500 kg of gem-quality material, from a total 120 tonnes of quartz mined each year. Amethyst averages the highest production (44%), followed by ametrine (33%), and citrine (23%); ametrine remains the most lucrative product.

The proportion of ametrine has actually increased (from 20% a decade ago) because of Mr. Rivero’s success in marketing gems that do not necessarily show the traditional split in amethyst and citrine colors. In the early years of the Anahí mine, ametrines were often faceted as emerald cuts showing a distinct color demarcation to mimic the appeal of bicolored tourmalines. But cutting ametrine for an even color split wastes much of the quartz. While “fantasy” cut gems have long ignored this purple-yellow color demarcation in favor of free-form shapes, Minerales y Metales del Oriente today focuses on a blend of colors in more traditional shapes (i.e., round, oval, or pear). This strategy maximizes yield. In addition to purple, the resulting mix of colors may exhibit “peach” or deep orangy red hues when viewed face-up (e.g., figure 3).

Figure 3. Anahí mine ametrine is cut to maximize yield while also blending the yellow and purple colors. The 33.55 ct gem on the left was cut by Dalan Hargrave; the 44.23 ct concave-cut stone on the right was faceted in Bolivia. Both gems courtesy of Minerales y Metales del Oriente; photos by R. Weldon.
For many years, Minerales y Metales del Oriente developed its own cutting styles and jewelry design prototypes, but contracted with overseas manufacturers for large-scale production. Until recently, it worked with a gem cutting and jewelry manufacturing plant in China. With the global economic downturn, today the company is producing all of its cut gems and finished jewelry in Santa Cruz. @chapter:1 @chapter:0 @chapter:1


# Publication Year: 2008
# Title: Spring 2008 Gem News International
# Abstract: Tucson 2008
            Emerald-Bearing Gem Pockets from North Carolina
            Spessartine from Loliondo, Tanzania
GNI Regular Features
Colored Stones and Organic Materials
            Gem-Quality Afghanite and Haüyne from Afghanistan
            A Blue Manganaxinite
            Gem News from Myanmar
            Gems on the Market in Taunggyi, Myanmar, 1990–2007
            Large Gem Pocket Discovered at the Oceanview Mine, San Diego County, California
            Green Sodic Plagioclase from East Africa
            A Blue Topaz with 2500+ Facets
Synthetics and Simulants
            An Imitation "Elephant Pearl"
            An Interesting Synthetic Sapphire
Treatments
            Lead Glass-Filled Color-Change Sapphire
Miscellaneous
            Myanma Gem Emporium Offerings for 1992–2007
Conference Reports
            2008 Winter Conference on Plasma Spectrochemistry
            Gemological LA-ICP-MS User Group (GLIUG) Workshop and Meeting
            First International Pearl Convention
Announcements
            New Portuguese-Language Gemology Newsletter
            Association of the Study of Jewelry & Related Arts
Exhibits
            Exhibits at the GIA Museum
            Diamond Divas
            Gems! Colors of Light and Stone at the Bowers Museum
            The Aurora Collection at The Vault
            Gold: Visions of the Americas
In Memoriam
            Grahame Brown (1936-2008), editor of The Australian Gemmologist

To view the full section, download the PDF above. @chapter:4 @chapter:0 @chapter:4


# Publication Year: -
# Title: Kunzite History and Lore
# Abstract: George Frederick Kunz

                      Kunzite is a relative newcomer to the array of colored stones available for use in jewelry. As the story goes, specimens of an as-yet-unidentified pink crystal were found in San Diego County, California, and sent to Tiffany & Co.’s mineralogist, George Frederick Kunz. The year was 1902. Kunz was able to confirm that the crystals were, in fact, spodumene, but the previously unrecognized color made the find a new variety of the mineral.

	This photograph of a kunzite crystal was taken by George F. Kunz, the pioneering gemologist the gem is named after. - Courtesy USGS
Charles Baskerville, a chemistry professor at the University of North Carolina and later the City College of New York, subsequently named kunzite in honor of George Kunz in 1903.

	This photograph shows Charles Baskerville’s historic collection of kunzite crystals. - Wendell Wilson
In the years since, kunzite has proven to be a highly desirable gem. Occurring in attractive shades of pink to violet, kunzite crystals are also often large, with relatively few inclusions. Though difficult to cut due to its two cleavage directions, it lends itself to lovely finished gems that show magnificently in fine jewelry.

	This lovely pendant features a pear-shaped kunzite with a diamond accent. - Robert Weldon, courtesy The Greenwood Group @chapter:1 @chapter:0 @chapter:1


# Publication Year: 2016
# Title: Growth Blockages in Cat’s-Eye Beryllonite
# Abstract: Figure 1. Left to right: a cat’s-eye beryllonite cabochon, two faceted transparent colorless samples, and a partially polished specimen with clean areas and growth tubes. The larger faceted stone in the center weighs 1.90 ct. The rough on the far right is the specimen from this study. Photo by Kevin Schumacher.

The sodium beryllium phosphate mineral beryllonite (NaBePO4) is a rare gem coveted by collectors. The material is typically fashioned as a transparent colorless faceted stone but occasionally as a cat’s-eye cabochon (figure 1). Recently, an interesting colorless rough specimen studied at GIA’s Carlsbad laboratory exhibited an unusually sharp, obvious separation between two regions. One area contained a high density of hollow tubes, while the other was clean and transparent.

Chatoyant beryllonite gems have been reported previously (Spring 1991 GNI, pp. 47–48), but this peculiar specimen offers a clue to the mechanism that gives rise to the chatoyant phenomenon. The answer lies in the separation between the two regions, which is where minute inclusions (figure 2) were deposited during growth of the crystal. This created a localized blockage of necessary nutrients, preventing growth of the host mineral and leaving behind the parallel tubes (Summer 2010 Lab Notes, pp. 55–56). This collector’s cat’s-eye beryllonite, with its beautiful contrasting black-and-white inclusion scene, furthers our understanding of chatoyancy in this mineral.

Figure 2. Two-phase inclusions and parallel tubes in a colorless beryllonite are the
result of growth blockages created by tiny crystal inclusions, shown in diffused
transmitted lighting. Photomicrograph by Jonathan Muyal; field of view 2.88 mm. @chapter:26 @chapter:0 @chapter:26


# Publication Year: 2013
# Title: Gemstones and Minerals
# Abstract: Nestled within this huge textbook on analytical archaeometry—an interdisciplinary field representing the interface between the natural and physical sciences and professions such as archaeology, art history, and museum curatorship that uses state-of-the-art technologies to extract structural and compositional information from ancient materials—is a useful chapter for today’s gem professional.

The modern gem trade’s embrace of science, technology, and the information sciences is perhaps best reflected in laboratory testing. Advanced laboratory services are often necessary to detect increasingly sophisticated treatments, and new manmade materials such as CVD-grown synthetic diamonds. Lab testing is also used to detect nanotechnology films for hardness and color enhancement, some sophisticated diffusion processes, and geographic origin, to name a few.

Chapter 10, “Gemstones and Minerals,” is a broad overview of several advanced spectroscopic and imaging techniques used in gemological and university laboratories to meet these modern needs. This 26-page chapter provides the gemologist, jeweler, and appraiser with succinct practical information, using numerous field examples, about advanced testing that can easily be communicated with clients.

The authors recognize that the foundational gemological methods (such as trained observation using magnification/microscopy, refractive index, specific gravity, ultraviolet indications, and optic character) often need to be augmented with advanced lab techniques, especially for conclusive determinations.

UV-visible near-infrared (UV-Vis-NIR) spectroscopy helps identify diamond treatments and determine the geographic origin of certain stones such as tourmaline and emerald. Fourier-transform infrared (FTIR) spectroscopy  helps in the detect of heat treatment in corundum and organic substances used for clarity enhancement, as well as the determination of diamond type. Other applications of FTIR include the separation of natural from synthetic origin in inclusion-free stones and the determination of jade type and treatments. Raman spectroscopy is an important tool in the study of inclusions, the detection of diamond and emerald treatments, and the identification of organic pigments in gems. Energy-dispersive X-ray fluorescence (EDXRF) and laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) are used in trace-element analyses, determining geographic origin, detecting beryllium treatments, and identify unknown or synthetic materials. Photoluminescence (PL) is applied to the study of natural and treated diamonds as well as pearls, spinel, rubies, and coral. X-ray imaging and radiography are widely used to evaluate cultured and natural pearls, including their treatments.

Abstracted by Edward R. Blomgren @chapter:27 @chapter:1 @chapter:27


# Publication Year: -
# Title: Emerald Description
# Abstract: A hand-held flashlight reveals the green color of a rough emerald from the Coscuez Emerald mine in Colombia. Photo by Eric Welch/GIA.

                      Emerald is the green to bluish green variety of beryl, a mineral species that also includes aquamarine as well as beryls in other colors.

Gem experts differ on the degree of green that makes one stone an emerald and another stone a less-expensive green beryl. Some people in the trade tend to give the name emerald to any green beryl colored by chromium. But to most gemologists, gemological laboratories, and colored stone dealers, it is more correct to call a stone green beryl when its color is "too light" for it to be classified as emerald. Even among that group, however, there's a difference of opinion about what's considered "too light."

GIA uses lab-graded comparison stones to determine if the green color is dark enough and saturated enough to be called emerald. @chapter:10 @chapter:0 @chapter:10


# Publication Year: -
# Title: Las Vegas 2015: Selective Demand Buoys a Slow Season
# Abstract: The 2015 JCK Las Vegas show was deemed a success by an industry that needed some good news after very disappointing sales in Hong Kong and Basel. Photo by Russell Shor/GIA

                      Business at the 2015 JCK Show in Las Vegas was good if you had exactly the right goods at the right price. Whether it was diamonds, colored stones or designer jewelry, buyers − which included major retailers, jewelry manufacturers and other dealers − came with very specific wants in mind and stuck to them. The show was deemed a success by an industry that needed some good news after very disappointing sales in Hong Kong and Basel.

Exhibitors at the accompanying Couture and Luxury shows generally outperform the other sections of the show and this year was no exception. One reason is that their retail clients – generally higher-end independents – have a strong base of return customers who collect pieces by many of these designers, so in a sense, their business is built-in.

Designer jewelry sold well throughout all of the shows if it had a high-end, one-of-a-kind look. At Couture, the pieces tended toward understated luxury with an emphasis on design instead of high gem content. The jewels tended to be showier at the Luxury show; designers favored frilly, curvy lines and lots of small gemstones set to create a larger look, such as blossom motifs with a lot of negative space, which made it possible for them to use less metal. In the sub-$1,000 market, bold, colorful looks were in; designers employed lower-priced color gems and beads like citrine and blue topaz and even non-gem material set into 14k gold or vermeil.

Diamond demand centered on excellent cut and medium-quality one- to two-carat stones. There was some demand for larger diamonds, but buyers were extremely selective. While buyers did roam the JCK show’s diamond pavilion and Luxury area, there were simply too few of them – the high U.S. dollar kept most Asians and Europeans away – to satisfy all of the exhibitors.

“People were buying just what they needed for the immediate future,” said one exhibitor who noted that buyers were also holding out in hopes that polished prices would decline over the summer.

Retailers have been very cautious about sales prospects for the second half of the year because jewelry demand has been slowing despite the improving economy and employment market in the U.S. In addition, banks have curtailed many of the generous memo programs that had made it possible for retailers to order large numbers of diamonds without payment due until the beginning of the following year.

Banks blame memo programs for some of the cash flow difficulties the industry is facing today and, quite often, the goods end up in dispute if the retailer or dealer files for bankruptcy.

Colored stone demand was equally selective.

A number of exhibitors at the American Gem Trade Association show that ran concurrently with JCK said the industry was still trying to come to grips with the decline of the Chinese market. Prices had soared for ruby and sapphire during the past five years, they explained, because Chinese dealers often outbid western dealers for the top goods – and even medium qualities. Now, the Chinese are not buying at the same level or are making lowball offers. Most of the major primary dealers in gem centers, however, are still holding out for those high prices. Many dealers and buyers believe prices are too high and this has brought much of the trade to a standstill and sent buyers searching for substitutes.

Buyers at the AGTA show were looking for red spinel as a much more affordable substitute for ruby and tsavorite as a substitute for emerald. Sellers of beads and lower-priced gems generally did well as retailers strove to keep prices affordable for their middle- and lower-market customers.

The JCK Show also hosted De Beers’ CEO Philippe Mellier who, in an address, acknowledged the diamond industry’s current difficulties, but said the long-term prospects would see solid growth, particularly in the U.S.

“No one gets the glamor of diamonds quite like the American consumer,” Mellier said, adding that its share of market was again increasing against newer markets like China and India.

An increase in the number of affluent U.S households (earning over $100,000 yearly), along with tourists from newer markets like China, will drive the growth of U.S. diamond jewelry sales.

Mellier noted that diamond mine production will begin to decline at the end of the decade and that, while De Beers is taking measures to lengthen the life of its resources, there are few promising finds on the horizon – only 60 out of 7,000 known kimberlites have been economically viable to mine.

Financial transparency and responsible sourcing are growing in importance, the first to regulators, the second to millennial consumers, while consumer confidence remains an on-going concern as treatments proliferate and synthetics enter the market, Mellier told the audience.

By the show’s closing, business proved strong enough to sustain diamond and gemstone dealers and offer a sense that the fall quarter may bring an upturn. @chapter:32 @chapter:3 @chapter:32


# Publication Year: 2007
# Title: Winter 2007 G&G Lab Notes
# Abstract: Apatite in Spessartine
Atypical Photoluminescence Feature in a Colorless Type IIa Diamond
Diamond Inclusions Fit for a Holiday Season
Diamond With Large Etch Channels Filled with Iron Sulfides
Natural Black Diamond with Oriented Etch Channel
The Pareidolia of Diamonds
A Notable Emerald Carving
Gold Coated Onyx
Sapphire with a Double Star
Impregnated Glass Imitation of Turquoise

To view the full section, download the PDF above. @chapter:43 @chapter:1 @chapter:43


# Publication Year: 2021
# Title: “C” is for Cookie and “G” is for Geode
# Abstract: Figure 1. A Brazilian geode shows a striking resemblance to the legendary Cookie Monster character. The intact geode measures 61 mm in length and 40 mm in diameter. Photo by Robert Weldon; courtesy of Mike Bowers.

“C” is for cookie and “G” is for geode. Gemstones are well known for their ability to mimic familiar themes, but the rock that recently launched a thousand online posts resembled one of the most recognizable children’s characters, the Muppet known as the Cookie Monster (figure 1). The uncanny likeness set the internet ablaze with reports from news sources around the globe. A video of the geode featuring Cookie Monster’s signature tune, “C is for Cookie,” was uploaded to Facebook by its owner, gem collector Mike Bowers, on January 16, 2021. The viral clip reached more than one million views just a week later. All the attention left many wondering, “How could a rock like this form?”
The discovery of the Cookie Monster geode, reportedly from Brazil, is a combination of geologic design and pure luck. It is composed of banded layers of microcrystalline quartz, commonly known as agate. The scientific processes required are complex but can be simplified into some general steps (J.D. Winter, Principles of Igneous and Metamorphic Petrology, Pearson Prentice Hall, Upper Saddle River, New Jersey, 2013). This type of geode occurs as a secondary formation when gas bubbles trapped in volcanic rocks, known as vesicles, are filled with silica-rich fluids. Over time, the fluids deposit concentric layers of microcrystalline quartz along the interior of the vesicle. The accumulation of these layers reflects the variation in chemistry and changing conditions of the silica-rich fluid. These fluctuating conditions can result in a banded formation of the microcrystalline quartz, thus giving rise to an agate. The final siliceous fluid in the last stage of formation allowed for a large central druzy quartz–lined cavity that represents the “mouth” of the Cookie Monster (figure 2, left).

Figure 2. This geode was serendipitously cut at a perfect angle, resulting in halves resembling the famous Cookie Monster (left). Coincidentally, the geode also showed blue fluorescence under long-wave ultraviolet light, reminiscent of the character’s blue fur (right). Photos by Robert Weldon; courtesy of Mike Bowers.
Cutting the rock at the perfect angle to reveal such a startling semblance was a matter of sheer chance, for the internal structure of a geode is not known until it is split open. Any slight change in cutting direction might have resulted in viewers not experiencing the phenomenon of pareidolia, the tendency to assign familiar shapes or faces to abstract forms (Winter 2007 Lab Notes, pp. 363–364).

“C” is for Cookie and “G” is for Geode

The color in blue agate is created by scattering of light; when the particles of silica are smaller than 400 nm, blue light is reflected back (G. Rossman, “Cause of color in agate and chalcedony,” Seventeenth Annual Sinkankas Symposium, April 24, 2021). When the rock was exposed to long-wave ultraviolet light, it revealed strong blue fluorescence (figure 2, right) consistent with the fur color of the famous Muppet. Also of gemological interest was a microscopic feature: Below the quartz-lined “mouth” was a small inclusion of yellowish limonite, a hydrous iron oxide, resembling a cookie crumb (figure 3).

Figure 3. A small impurity of yellow limonite resembling a cookie crumb was found under the “mouth” of the Cookie Monster. Photomicrograph by Nathan Renfro; field of view 4.70 mm.
While geodes can be millions of years old, the Cookie Monster character only emerged within the last century. The Cookie Monster, originally created as a prototype in 1966 by Jim Henson, debuted on the American educational children’s television series Sesame Street in 1969. The name was taken from his incessant obsession with the baked goods. With Sesame Street still on the air today, after 51 seasons, Cookie Monster’s fame is sealed in pop culture.
It was a fortuitous circumstance that the formation of the geode resulted in such a remarkable specimen. As GIA analytical microscopist John Koivula likes to say, “Mother Nature cooks in a dirty kitchen.” Who knows what she will cook up next, but one can hope it has us all cracking open a smile once more. @chapter:27 @chapter:0 @chapter:27


# Publication Year: 2005
# Title: Spring 2005 G&G Lab Notes
# Abstract: Diamond with Bodycolor Possibly Affected by the 3H Defect
HPHT-Treated Type IIa Yellow Diamond
Inhomogeneous Cape Diamond
Irradiated and Fracture-Filled Diamond
A Coated “Night Glowing Pearl”
Covellite in Quartz
Rock Crystal Quartz with Unusual Surface Texture
Sphene Cabochon with an Unusual Natural Surface

To view the full section, download the PDF above. @chapter:43 @chapter:1 @chapter:43