# Publication Year: -
# Title: A Sunstone Odyssey, Part 1: The Ponderosa
# Abstract: John Woodmark, CEO of the Ponderosa mine, is a man in his element. Photo by Robert Weldon.

THE MINE'S LOCATION

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	In this slideshow, you will explore the Ponderosa mine, learn about its gem recovery processes, and view the beautiful sunstones that originate in the rocks of southeastern Oregon.
With a sweep of his arm, John Woodmark invites us to take in the majestic vista below: “You can see the large meadow… it stretches for miles. That used to be an ancient lake…Native American people have been in here for 15,000 years, hunting around that lake.” He adds some more-recent history, telling us: “Into the 1900s, they were still camping in this area and using the dried-up lake bed as pasture for their horses.”

This connection to the native people extends to the present day. Woodmark partners with the local tribal outreach program to offer seasonal employment to Native American teens at the Ponderosa mine. This is something Woodmark is very proud of, and we’ll return to it a little later.

Right now, we’re standing on the steep slopes of Donnelly Butte, just above the Ponderosa mine’s pit. At our backs, magnificent stands of lofty ponderosa pines extend uphill. We are about a five-hour drive from Portland, Oregon, and the transition from that busy city to the silence and serenity of the Ponderosa is jarring.

Beneath us, entombed in an ancient lava flow, millions of carats of rough sunstone—Oregon’s state gemstone—await discovery. The Ponderosa mine is possibly the state’s most important source of the repeatable commercial sizes required by jewelry manufacturers.

	The red rocks of the Ponderosa mine’s pit complement the setting sun. Photo by Robert Weldon.
The beauty of the mine’s location isn’t lost on Woodmark: “It’s a pristine area, it’s beautiful…It’s wonderful just to come up here, let alone find a truly exotic gem like Oregon sunstone.” With this in mind, he strives to make his mining activities as low-impact as possible: “We’ve got over a million board feet of huge ponderosa, most of them in the 250 to 300 year old range, and we’re trying very hard not to disturb any of those trees and still get the same stones that we need to mine.”

Beyond the direct environmental impact, Woodmark and his crew also have to synchronize their mining to the regional climate. These are Oregon’s High Lava Plains, after all, and the winters can be brutal: “The mine is located at 5900 ft., so from October to June we’re covered with as much as ten feet of snow up here, so there’s absolutely no mining during those months.”

Despite these constraints, he knows the Ponderosa’s weathered reddish basalts are blessed with high concentrations of sunstone: “This mine is tremendously rich—the whole mine is 60 acres—and we get a kilo and a half of sunstone out of every cubic yard of dirt moved…so it’s arguably one of the richest gemstone mines in the world.”

Because of the richness of this deposit and the weathered nature of the basalt around the gems, they’re easier to recover than at some of Oregon’s other sunstone locations. Woodmark explains: “We do ten-day mining stints…sometimes four to five times throughout that four month period…It all depends on the demand for Oregon sunstones…the more demand, the more often we mine.”

	Introducing the Ponderosa

	John Woodmark, CEO of Desert Sun Mining & Gem, provides a brief history of the mine and its location, as well as explains how the Ponderosa’s location at 5,900 ft. affects the mining season.

BEAUTIFUL SUNSTONE
Woodmark is passionate about sunstone: “You never get tired of it…it isn’t like you’re mining amethyst, which is all purple. Ours is so many different colors, every stone is unique.” As he talks on, his enthusiasm and love of this unique gem is infectious: “You can get reds, with just a sprinkling of the copper platelets, which makes it look like you’re looking into a red sky with gold stars…It’s just gorgeous.”

	A rare 11.76-ct. bicolor sunstone gleams with an added bonus of glittering, reflective copper platelets. Photo by Robert Weldon.

	This group of red sunstones reflects recent production from the mine’s pit. Photo by Robert Weldon.
He draws our attention to sunstone’s unique hallmark—tiny particles of native copper metal that produce a glittering effect called schiller. “And then you have the intense schiller…When the sun hits it and it just pops out at you…you can’t even believe it!”

	Beautiful Gems, Pristine Location

	Owner John Woodmark introduces us to the Ponderosa Mine’s pristine location and explains how the gems from the mine mirror the natural beauty of the environment.

THE PONDEROSA MINING PROCESS
Woodmark is determined that we see all of the mine’s operations and witness the recovery of gem sunstone directly from the pit wall. We start right at the wall, which bears sets of deep, parallel gouges. He mentions this is the work of the “magic finger,” developed by a member of his crew as an attachment for their backhoe, and which makes mining much easier.

	Pickers scour their screens for the gleam of red sunstone. Photo by Robert Weldon.
He directs us to a rich red area of the pit wall. “In the rest of the mine, we only get about one-and-a-half to three percent red.” This patch, he asserts, is very different: “This area produces twenty percent red to the volume that we’re picking…so rich it’s incredible.”

Woodmark adds that the backhoe’s special attachment—basically a flattened metal spike—was the missing ingredient: “We haven’t monkeyed around with anything else since we got our ‘magic finger’ to break this stuff down. Before, it was too hard for our machines to work.”

Once enough of the pit wall is torn down by the backhoe, a small loader moves the ore onto an area of the pit floor. Next, the Ponderosa crew runs their massive forty-thousand pound loader over the material to crush it and loosen the stones.

The loader feeds the crushed rock through a dry trommel—a rotating screen that, with the harsh clatter of stone on metal, separates the dirt from the ore-bearing material. The next stage is a second trommel, this time using water. John tells us this piece of equipment takes the concentrate and “washes it, scrubs it, and knocks off a little bit of the volcanic crust that’s on the crystals.”

One load fills about twenty five-gallon buckets. The buckets quickly stack up behind each of the three screening stations set up at the time of our visit.

A picker stands behind each screen. Woodmark picks up a bucket of concentrate and pours the contents onto a screen to demonstrate for us: “We…throw all the big rocks off…spread it out fairly evenly…” He picks up a hose and directs a jet of water over the concentrate. “…then come back and spray it down.”

He pauses to pick up a choice piece of sunstone. “Nice red,” he observes. “And then we start…systematically going through the whole screen.” With a small trowel, he works methodically from one end of the screen to the other, telling us, “What we try and do is turn every stone…leave no stone unturned we tell the kids…so you start at one end and you just systematically turn every stone.”

	We recovered this nice specimen of zoned sunstone crystal in host basalt after it passed through the wet trommel. You can see that the crystal was originally considerably larger. Photo by Duncan Pay.
John’s diligence pays off with a small handful of rough sunstone, “You’ll get a handful like that off every screen…which probably weighs a few ounces.” He drops the red pieces into a plastic cup and tosses yellow or colorless rough into a bucket next to his feet. “They’ve got to go through a lot of screens to get a kilo…but like I say, they’ll pick about ten kilos on average per day.”

John emphasizes that speed is of the essence: It’s important to go through the screens quickly but accurately. “Don’t miss a thing, and get on to the next screen.” His rule of thumb is that the more screens you go through, the more you’re going to make: “I’ll do a screen every five-to-six minutes…it’s important not to jump around…because you’ll start to miss them.”

John’s eyes scan methodically from one end of the screen to the other, his trowel making quick movements to flip over the larger pieces: “A lot of our stones have a volcanic crust on them and even though they’ve gone through all the processes to get here, they’re very hard to find, so we go through it very methodically.”

“Don’t leave a stone unturned…” he admonishes us, “…because sure enough, there will be a red one hiding underneath there…and we don’t want to miss a red one.”

Once all the concentrate from a load is recovered, it’s washed for about an hour in a small cement mixer, which takes about 35 kilos at a time (60-70 pounds). “It’s almost like a rock tumbler…a giant rock tumbler,” Woodmark jokes.

When John tips out the mixer, there’s a crystalline glitter and tinkle as freshly washed rough cascades onto a small screen. “I’m looking for how many reds and how much schiller is in there…I’m looking for good stones that will bring money.”

He plucks out a limpid chunk of feldspar. “There’s a beautiful yellow…it’s a nice big size…see how clear and nice that stone is…that’ll make a terrific stone.” And then, a better prize: “Here’s a beautiful red…that’s going to make a tremendous faceted stone!”

The final step at the mine is to grade all this freshly cleaned concentrate. John leads us to a small table in front of the mine’s bunkhouse, where trays of sorted rough—reds, bicolors, schiller stones, yellows, and clears—rest in water-filled metal trays. The water cuts down reflections and helps with grading, he explains. There, in the shadow of tall ponderosa pines, John outlines the qualities a really fine gem might have: “The pinnacle is if it would be good enough to make a carving. A carving has to be something over 25 carats finished.”

He continues, “It has to have all the attributes…color…schiller…so it really is the pinnacle of an Oregon sunstone…We sell them for a lot of money…That’s just one in thousands of stones that we find.”

	Mining Sunstone at Ponderosa

	In this series, Ponderosa Mine owner John Woodmark explains how his crew goes about mining and processing, and grading rough sunstone.

NATIVE AMERICAN PICKERS
John is proud of his partnership with the local tribal outreach program, which started with five kids in 2006 and continues to the present. “We’ll pick for ten days at a stint,” John tells us. “After ten days, they’re burnt out picking stones and standing down there in the hot sun.”

	The Ponderosa partners with the local tribal outreach program to use Native American pickers. Photo by Jeff Jessing, Nature Revealed Photography, © 2009; courtesy of Desert Sun Mining Group
Unfortunately, at the time of our visit, there had been a robbery at the reservation and all the teens had left to assess the damage. However, each of us spent several hours working the screens, just as the pickers do. This gave us a very good concept of these kids’ “Ponderosa experience.”

	A lucky picker’s haul: A fine collection of “reds” decorate this screen. Photo by Robert Weldon
John outlines how his outfit houses, feeds, and pays the teen pickers: “For most of them it’s the most money they’ve ever had of their own…so the kids have all been absolutely great…they’re respectful, they’re glad to have a job, and all of us mentor them around the campfire.”

	A red crystalline glint in a scattering of red rock attracts this worker’s attention.
	Photo by Robert Weldon
To John, the amount of work he can provide hinges on the success of his business and, in turn, the popularity of sunstone with the jewelry-buying public. “The more sunstones we sell, the more people we can then hire,” he explains. “So if more people would get in behind Oregon sunstones, we’d have a lot more kids working here.”

	Employing Native American Teens

	The Ponderosa mine has an arrangement with the local tribal non-profit to provide work experience for Native American youth. The mine’s owner describes the benefits for both parties.

PROFIT
Woodmark is a savvy businessman, successful in many ventures before he acquired the Ponderosa mine. He applies the same financial acumen to sunstone as he would to any other commodity; “A kilo of red is worth twenty thousand dollars…we’ve got 25 of them in five days.”

	This choice piece of red sunstone rough will make a fabulous faceted gem. It’s just one piece in the 25 kilo haul the Ponderosa miners recovered during this trip. By Robert Weldon.
"We average 600 cut carats per kilo…an average price of 100 dollars per carat, I mean…is sixty thousand dollars…times 25…” He leaves us to do the math. “Yeah,” says Woodmark finally with a smile, “I think it’s pretty profitable!”

	Value of Rough Stones

	CEO John Woodmark explains the economics behind sunstone recovery at the Ponderosa mine.

THE GREAT ANDESINE CONTROVERSY
When we ask John about the andesine issue, there’s a hint of resignation in his answer. “Around 2004 or so, we started running into resistance because of a product out of China called andesine.” He explains that the jewelry channels jumped on it because every stone looked exactly alike, and as he puts it, “They could get them for nothing and sell them for a lot.”

Then for four years, while gemologists and geologists the world over tried to prove the authenticity or treated nature of this new gem, sales of Oregon sunstone were flat because people were afraid to invest. John is pragmatic on this topic: “We got hundreds of thousands of dollars’ worth of gemologists’ time and effort to prove that the andesine was a treated stone, but it also verified that Oregon sunstone was all natural.”

John contends that all the publicity over andesine was, in reality, a public relations blessing. “Nobody ever heard about Oregon sunstone before this andesine mess. Now everybody knows andesine was trying to be like an Oregon sunstone.”

In the three years since andesine’s treated nature was confirmed, John asserts his sales have increased year on year.

	Treated Andesine's Impact

	Recent issues with treated feldspar have impacted the market for natural Oregon sunstone. In this video, John Woodmark describes how his business was harmed, but also outlines some unexpected benefits from the affair.

SELLING SUNSTONE
Most consumers know about diamond, ruby, sapphire, and emerald, and might well favor those Big 4 gems. John understands it takes time and effort to open peoples’ eyes to sunstone’s unique attributes. “You have to sell an Oregon sunstone,” he says. “Most customers don’t know what it is.”

“The whole process of educating people and telling them about it,” he explains, “makes the stone personal.”

One of the qualities that make handling sunstone a challenge for commercial jewelry manufacturers—the uniqueness of individual gems might make them hard to match in jewelry—can play well with enlightened consumers looking for something different.

“We tell them about the uniqueness of having the copper particles in the stone, which makes their stone as unique as a snowflake,” John continues. Finally, he adds another set of strengths: “This is an American gemstone, picked by Native Americans…It’s only found in America, and it’s rare and exotic…so you know, it’s a terrific stone.”

	Educating Customers

	CEO John Woodmark explains his belief that the key to acceptance of sunstone as a mainstream gem lies in consumer education. @chapter:17 @chapter:0 @chapter:17


# Publication Year: 1997
# Title: Fall 1997 G&G Lab Notes
# Abstract: Cabochon Cut Diamond
Rare Fancy Vivid Orange Diamond
Diamond with Surface Droplets of Filling Material
A Faceted Cat’s-Eye Emerald
Impregnated Jadeite Jade with Exceptional Transparency
Resembling Nephrite Jade
Synthetic Green Periclase
Quartz Quench-Crackled and Dyed to Imitate Amethyst
Topaz Fashioned to Imitate Diamond Rough

To view the full section, download the PDF above. @chapter:18 @chapter:1 @chapter:18


# Publication Year: 2002
# Title: Liddicoatite Tourmaline from Anjanabonoina, Madagascar
# Abstract: Liddicoatite, a calcium-rich lithium tourmaline, was recognized as a separate mineral species in 1977, and named in honor of Richard T. Liddicoat. Most of the remarkable polychrome tourmalines with varied geometric patterns that are characteristic of this species were produced during the 20th century from the Anjanabonoina pegmatite deposit in central Madagascar. To best display its complex color zoning and patterns, the tourmaline is commonly sold as polished slices or carvings. Liddicoatite exhibits physical and optical properties that overlap those of elbaite, so quantitative chemical analysis is required to distinguish these species; both may occur in a single crystal. The most common internal features are color zoning, strain patterns, partially healed fractures, feathers, needle-like tubes, negative crystals, and albite inclusions.

	DATA DEPOSITORY

Table 1: Samples from Madagascar
Table 2: Samples from Localities Other Than Madagascar
	Submitted by Brendan Laurs
	May 17, 2002
	Notes: These tables provide all of the chemical data on liddicoatite-elbaite tourmaline that were obtained for this article. The references cited in the table are listed in the reference list of the original article. @chapter:12 @chapter:0 @chapter:12


# Publication Year: 2013
# Title: Silicon in Natural Type IIa and Type IaB Diamond
# Abstract: The presence of Si in diamond is typically revealed by detection of the 736.6/736.9 nm (“737 nm”) doublet zero-phonon line (ZPL), observed by either absorption or photoluminescence (PL) spectroscopy. This feature has been assigned to the negatively charged state of the silicon split-vacancy defect, SiV–, which is frequently incorporated into CVD synthetic diamonds due to the etching of silicon-containing growth chamber components. Conversely, reports of the 737 nm peak in natural or HPHT synthetic diamonds are notably rare (see C.M. Breeding and W. Wang, “Occurrence of the Si-V defect center in natural colorless gem diamonds,” Diamond and Related Materials, Vol. 17, 2008, pp. 1335–1344; Winter 2010 Lab Notes, p. 302; Winter 2012 Lab Notes, pp. 304–305). Consequently, this feature is considered an important tool for identifying CVD synthetic diamonds.

Recently, SiV– was detected in the PL spectra (liquid-nitrogen temperature with 633 nm laser excitation) of five diamonds submitted to GIA’s Mumbai laboratory. These 0.31–0.90 ct round brilliants were issued colorless grades of either D or E. Their clarity grades ranged from VVS1 to SI2, where the lower grades arose from the presence of trapped crystalline inclusions.

FTIR spectroscopy revealed that four of the samples were type Ia, with hydrogen-related peaks at 3107 and 1405 cm–1. The remaining sample was type IIa, with no discernible impurity-related IR features. Multi-laser, liquid-nitrogen-cooled PL spectra acquired for the fifth sample were similar to those reported in Breeding and Wang’s 2008 investigation of SiV– in natural diamonds. The latter also showed
luminescence at 737, 714.6, 589.8, 557.8/558.2, 554.2, and 550.3 nm, in addition to NV0/– (575 and 637 nm, respectively) and 3H (503.4 nm). This SI2 sample contained several inclusions with intact crystalline faces, identified by Raman spectroscopy as olivine, consistent with the former investigation (figure 1, top). Through gemological and spectroscopic observations, it was possible to distinguish this natural type IIa diamond from Si-containing type IIa CVD synthetics.

	Figure 1. Room-temperature Raman spectroscopy (830 nm laser excitation) identified the different inclusions in the type IIa, SI2 (top) and type IaB, SI1 (bottom) natural diamonds containing silicon. The former spectrum is consistent with olivine, while the latter is attributed to spessartine garnet.

The type Ia diamonds studied by Breeding and Wang all contained A-aggregates and varying concentrations of B-aggregates (type IaA±B). In the present group of type Ia diamonds, only B-aggregates were detected (pure type IaB). With the exception of the 737 nm feature, the type IaB diamonds’ PL spectra did not include any of the spectroscopic features characteristic of Si-containing type IaA±B diamonds. An emission line at 664.3 nm was detected in all the type IaB specimens, however. These samples also showed emissions from NV0/– (575 and 637 nm, respectively), H3 (503.2 nm), and H4 (495.9 nm), where H4 was remarkably strong for three of the diamonds. Interestingly, the diamond with the lowest H4 concentration was also distinctly included (SI1 clarity). Raman spectroscopy identified the inclusions as spessartine garnet (figure 1, bottom). Breeding and Wang also reported the presence of garnet in Si-containing diamonds. The presence of olivine and garnet inclusions in natural diamonds containing SiV– has been suggested to indicate that they crystallized in an area of mixed-composition peridotite in the upper mantle.

These results emphasize that the detection of SiV– in diamonds does not unequivocally signify CVD synthetic origin. Nevertheless, careful analysis of spectroscopic features and crystalline inclusions can be used to separate these natural diamonds and their synthetic counterparts. @chapter:9 @chapter:1 @chapter:9


# Publication Year: 2010
# Title: Hibonite: a New Gem Mineral
# Abstract: A 0.23 g orangy brown crystal, a 0.39 ct step-cut gem later faceted from it, and a 0.71 g crystal—all reportedly from Myanmar—were characterized for this report. Infrared spectroscopy, X-ray diffraction, and chemical analysis dentified the material as hibonite. These samples represent the first gemquality hibonite ever recorded. @chapter:0 @chapter:0 @chapter:0


# Publication Year: -
# Title: Emerald Journey
# Abstract: Few people outside the gem industry realize the true nature of a gemstone’s journey from the mine to the counter of a store. Whether the gem is being offered to consumer’s at a traditional jewelry store’s counter, an internet shopping site, or a television broadcast the journey always involves a great deal of effort.  Tons of earth and countless hours of labor are needed to bring a gem from mine to market. @chapter:38 @chapter:3 @chapter:38


# Publication Year: 1986
# Title: A Simple Procedure to Separate Natural from Synthetic Amethyst on the Basis of Twinning
# Abstract: Dr. Karl Schmetzer recently showed how near-flawless to flawless natural amethyst could be separated from synthetic amethyst on the basis of the presence of Brazil twinning in the natural stones. Whereas Dr. Schmetzer's procedure required a special apparatus, the authors have determined that a standard gemological polariscope is more than adequate to make the separation in most cases. Although some synthetic amethyst does show evidence of twinning, in the synthetic stones examined thus far it has taken a form that is distinctly different from the Brazil twinning seen in most natural amethysts. The presence of certain inclusions as well as the nature of the color zoning seen in natural versus synthetic amethysts is of primary use in making a separation. However, where there are no inclusions or color zoning, the presence of Brazil twinning in the natural amethyst will usually make the distinction. @chapter:5 @chapter:0 @chapter:5


# Publication Year: 2016
# Title: Macedonian Ruby Specimens
# Abstract: This 9.93 ct ruby cabochon from Macedonia was seen at the Jewellery & Gem Fair – Europe in Freiburg, Germany. Photo by Russell Shor/GIA.

	The Macedonian town of Prilep has been a source of marble since antiquity, even supplying some Roman settlements. Rubies have occasionally been found within the Bianco Sivec quarry, according to gem dealer Denis Gravier (Gravier & Gemmes, Poncin, France). Although Prilep is mainland Europe’s only known natural ruby source, only in the past 15 years has there been an effort to mine the gems. Gravier offered several rubies from the Prilep quarry at the March 19–22 Jewellery & Gem Fair – Europe in Freiburg, Germany, including the 9.93 ct cabochon seen above. None of the specimens were faceted. Gravier said the deposit produces comparatively few gem-quality rubies, and most are too cloudy for faceting. The best ones have a distinct “raspberry” color. It is unknown whether any of the material is heat treated. Macedonian craftsmen have developed a local industry using these rubies in jewelry and objets d’art. @chapter:4 @chapter:0 @chapter:4


# Publication Year: -
# Title: Top 10 Digital Reads from the GIA Library
# Abstract: Gem materials, such as this agate (a Chinese carving of Guanyin), Colombian emerald specimen, pearl, shell cameo, amethyst, garnet and turquoise, have excited global appeal for millennia. Books about gemstones, but also geology, mining techniques and international trade in gems, have long stimulated enthusiasts. Many are collected in GIA’s Cartier Rare Book Repository and Archives, which houses both the ancient and more modern writings about gemstones. A growing number of these books (treasures in and of themselves) are available to you — for free —through Internet Archive. Photo by Robert Weldon/GIA.

Would you like to brush up on your Latin and read Pliny’s “Natural History,” the 17th-century book that is the foundation of ancient gemology? Peruse an 1817 copy of Sowerby’s “British Mineralogy” with your morning coffee? Or thumb through — virtually — an especially rare, 1925-26 catalog of Russian Romanov dynasty’s regalia and crown jewels?

These are just three of 650 digitized rare books from GIA’s Cartier Rare Book Repository and Archives that are available for free through the nonprofit digital library Internet Archive. This multi-year effort by librarians at GIA’s Richard T. Liddicoat (RTL) Gemological Library and Information Center to bring thousands of the rarest, most venerated books in gemology, mineralogy and jewelry into easy reach.

Many of the books are from the Sinkankas Library, which was acquired by GIA in 1988. John Sinkankas, a noted author and lapidary artist, and his wife Marjorie, spent more than 40 years collecting approximately 14,000 items, including virtually all of the major works related to the study of gems and jewelry.

“The GIA digital library is growing into a comprehensive collection of manuscripts and books that document centuries of history, art, science, gemology and mineralogy,” says Robert Weldon, director of the RTL Library. “Reflecting the many countries and languages that make up the international world of gems and jewelry, online archive is an excellent resource for gemologists and researchers — available at their fingertips, no matter where they are.”

TOP 10 DIGITIZED BOOKS
Here are some of the most notable books, as selected by the library staff:

Fersman, A.E. Russia’s Treasure of Diamonds and Precious Stones, 1925
	This rare catalog documents Russia’s regalia and crown jewels at the time of the overthrow of the tsarist regime in 1917. It includes jewels that date from the reign of Peter I (1689-1725) through Nicholas II (1894-1917), with 100 photographs of the Tsarist riches.

Kozminsky, Isidore. The Magic and Science of Jewels and Stones, 1922
	From ancient myth to modern science, this book is (from the preface) "…a sincere attempt…to blend modern science with the ancient and occult philosophy of the … stones of the earth.”  Sinkankas describes it in his Gemology: An Annotated Bibliography as "An outstanding work, comparable to Kunz’s Curious Lore in respect to authenticity & accuracy of information.”

Hendley, Thomas Holbein. Indian Jewellery, 1909
	This rare work is a collection describing the jewelry, costumes and gemstone terminology of the Indian provinces. Sinkankas calls it the “largest, most detailed, and lavishly illustrated monograph ever to appear on the subject.”

Vever, Henri. La Bijouterie Francaise au XIXe Siecle (1800-1900), 1908
	This three-volume work describes the history of French jewelry, including famous gems, persons and pieces. Sinkankas lauds it as “astonishingly detailed” and “remarkable for the numerous high quality photographic and other illustrations.”

Winter, Albert Andrew. A Course in Fundamental Principles of Designing and Engraving, 1915
	This 1915 instructional book from Winter’s School of Jewelry Engraving is a practical guide in basic engraving, which includes explanations on monogram design, letter formation, proper tools and techniques, types of metals, terminology and more. The explanations are accompanied by detailed illustrations and diagrams.

Tagore, Sourindro Mohun. Mani-mala: or, A Treatise On Gems, 1881
	In English and Sanskrit, Tagore’s two volume Mani-Málá includes both Eastern and Western sources of information on diamonds and colored stones, lore, jewelry, royal gems and more. Sinkankas calls it “one of the most remarkable and important works on gems ever published,” especially as a resource for the history of gemstones in Indian culture.

Kunz, George Frederick. The Curious Lore of Precious Stones, 1913
	This work is a significant and comprehensive assemblage of information on gemstone folklore and healing properties. Learn about the mystical properties that many — to this day — ascribe to gems.

Lacroix, Alfred. Mineralogie de la France et de Ses Colonies […], 1913
	Are you fascinated by minerology? Do you read French? This five-volume work “describes the minerals of France and its colonies. Sinkankas describes it as […] peer, being extremely thorough, neglecting no important aspect, and lavishly illustrated."

The Bishop Collection: Investigations and Studies in Jade, 1900
	A rare collection of articles on jade, commissioned by Heber Reginald Bishop to describe his collection of jade objects, which was donated to the Metropolitan Museum of Art in New York in 1902.

Pliny, the Elder. C. Plynius Secundus De naturali hystoria diligentissime castigatus, 1496
	This 1496 Latin edition is the oldest book in GIA’s collection. Its 37 chapters are a compilation of all that he could discover about nature; the last five books cover metals and gems. As gemologist and author Sydney Ball explains, it was the foundation of all science until the Renaissance, and is one of the largest single works to have survived from the Roman Empire to the modern day.

Learn more about how GIA is digitizing its rare book collection. @chapter:31 @chapter:2 @chapter:31


# Publication Year: 2016
# Title: Very Large Artificially Irradiated Yellow Diamond
# Abstract: Figure 1. This 59.88 ct Fancy Vivid yellow diamond was treated through artificial irradiation and annealing. Photo by Jian Xin (Jae) Liao.

Artificial irradiation and annealing to enhance or change color is one of the oldest diamond treatments. English chemist Sir William Crookes first discovered the effects of radiation on a diamond’s color, conducting experiments using radium salts in 1904. Today, only a very small percentage of all natural diamonds are irradiated, typically with an electron beam. Because of the risk of damage, diamonds subjected to this treatment are typically under 10 carats.

A 59.88 ct yellow diamond (figure 1) recently examined at the New York laboratory received clarity and color grades of SI1 and Fancy Vivid yellow. While the face-up color distribution was classified as even, we observed a moderate color concentration along the culet typical of some artificially irradiated diamonds (figure 2). Microscopic examination showed noticeable crystal inclusions at 10× magnification as well as extensive burn marks across the entire surface of the stone. The diamond showed chalky blue fluorescence under long-wave UV excitation and medium yellow fluorescence under short-wave UV.

Figure 2. Strong color concentration along the diamond’s culet is evidence of artificial irradiation. Photo by Christopher Vendrell.
Using a desktop spectroscope, the diamond’s visible absorption spectrum revealed a series of absorption lines between 415 and 477 nm, indicative of a “cape” diamond. Additionally, an unusually strong peak at 503.2 nm (H3) was noted using a UV-visible spectrometer (figure 3). The enhancement of this H3 center is responsible for the very desirable yellow color. The infrared absorption spectrum showed high concentrations of nitrogen in the one-phonon region, indicating type Ia diamond. Further examination of the infrared region revealed a minor hydrogen defect as well as weak to moderate peaks at approximately 4935 cm–1 (H1b) and 5165 cm–1 (H1c), further evidence of treatment.

Figure 3. The yellow diamond’s Vis-NIR absorption spectrum shows a strong peak
corresponding to the H3 defect observed at about 503 nm.
These features led to the conclusion that the diamond was artificially irradiated and annealed (by introducing the H3 defect) to induce a more desirable yellow color. This was by far one of the largest artificially irradiated diamonds identified at GIA, surpassing previous examples by several carats (see Summer 2012 Lab Notes, p. 132; Winter 2014 Lab Notes, p. 295). This diamond reiterates the importance of careful analysis, since even the largest stones may have undergone treatment. @chapter:22 @chapter:1 @chapter:22


# Publication Year: 2021
# Title: HPHT-Processed Diamond with Counterfeit GIA Inscription
# Abstract: Figure 1. Face-up view of the 1.497 ct, E-color HPHT-processed diamond submitted in 2021 for update service. Photo by Ellen Barrie.

In June 2021, GIA’s Antwerp lab received a diamond treated by high pressure and high temperature (HPHT) that was falsely inscribed with a GIA report number referencing an untreated diamond originally graded by GIA in 2010. The diamond was submitted for Update service, in which a stone is matched to its previous report and regraded based on its current condition. Careful comparison of the diamond with its accompanying report number showed that the weight and grading parameters were very similar, but certain differences readily led to the conclusion that this was not the same stone.
The HPHT-processed diamond was a round brilliant weighing 1.497 ct and measuring 7.30–7.34 × 4.50 mm (figure 1), while the original diamond weighed slightly more (1.502 ct) and measured 7.29–7.34 × 4.56 mm. They had the same clarity (IF) and fluorescence (none) but different color grades (D for the original diamond, E for the HPHT-processed diamond).
Additional conclusive differences were detected when the newly submitted stone was further analyzed with advanced spectroscopic techniques. Whereas the diamond from 2010 was type Ia, the submission from 2021 tested as type IIa. Photoluminescence (PL) spectroscopy using various laser excitation wavelengths confirmed a natural origin, but with color enhancement by HPHT treatment.

Figure 2. Remnants of the original GIA report number could still be detected on the girdle of the diamond (in addition to the fraudulent inscription, which is not pictured). Photomicrograph by Ellen Barrie.
In addition to a clearly fraudulent inscription (not pictured), microscopic examination of the girdle revealed remnants of an original GIA inscription (figure 2). Based on this information, we found that this HPHT-processed stone had already been submitted to GIA in 2013 but was repolished afterward in an attempt to obscure the original inscription. Our records showed that in 2013, the diamond was also inscribed with “BELLATAIRE” (indicating HPHT treatment), but this information had been removed from the girdle and the remnants were even less visible than the original GIA inscription.

Figure 3. “TREATED COLOR” was inscribed on the girdle after spectroscopic analysis confirmed that the color of the stone was enhanced by HPHT treatment. Photomicrograph by Ellen Barrie.
In addition to issuing a new report for this HPHT-treated diamond, GIA made the fraudulent inscription unreadable, according to standard procedure, and the stone was inscribed with “TREATED COLOR” (figure 3).
The Antwerp lab had recently reported a similar case of fraud, but that concerned a laboratory-grown diamond with a counterfeit inscription referencing a natural diamond (Summer 2021 Lab Notes, pp. 150–152). Both types of fraud are common in the marketplace and show the importance of careful verification of not only a diamond’s growth method (natural versus laboratory-grown) but also its color origin. @chapter:36 @chapter:1 @chapter:36


# Publication Year: -
# Title: Spring 2021 G&G Available Now
# Abstract: A variety of topics are in store for you in the Spring issue of G&G. First up is a study of the internal structures of natural pearls collected from wild marine mollusks. The second article explores the effectiveness of resin as a pore-filling treatment to improve the appearance of rough turquoise specimens. Next, visible spectroscopy and a mathematical function are used to predict the color of a uniaxial gem material when viewed in any direction. And spinel, which has become increasingly popular among jewelry artisans and aficionados, inspires a colorful chart displaying the many types of inclusions found in this fascinating gem.
Internal Structures of Known Pinctada maxima Pearls: Natural Pearls from Wild Mollusks
This issue’s lead article, by Artitaya Homkrajae and fellow pearl researchers from GIA, spotlights the importance of reliably sourced natural pearl samples. With the help of the Paspaley Pearling Company, the GIA team collected wild P. maxima mollusks off the coast of Australia to compare their internal structures with those of pearls from other sources. This study adds to gemologists’ understanding of natural pearl identification.
Technical Evolution and Identification of Resin-Filled Turquoise
China’s Hubei Province has long been a source of commercial turquoise production. Using a variety of detection techniques, Ling Liu and a team from the Gemmological Institute, China University of Geosciences in Wuhan researched the widespread treatment of filling porous turquoise with resin. Their conclusion was that this is an effective method of improving rough turquoise quality and, like any treatment, should be disclosed to consumers.
How to Calculate Color from Spectra of Uniaxial Gemstones
Understanding the color characteristics of a gemstone can provide a scientific basis to guide its cutting. This study uses visible spectroscopy and a mathematical method to determine the unpolarized spectra of a uniaxial material from the polarized spectra (o-ray and e-ray) in order to predict the color of a uniaxial gem material when viewed in any direction.
Micro-Features of Spinel
Nathan Renfro and co-authors add to the G&G series of micro-feature charts with this lovely display of inclusions found in spinel, a previously under-appreciated gem that is now gaining in popularity due in part to its wide range of colors. The chart is included in every printed copy of this issue, and a laminated version is available for sale in the GIA Store.
Lab Notes
GIA laboratory staff present their latest findings in the Lab Notes section, including two diamond cabochons displaying rare asterism, a precious cat’s-eye opal with patches of color producing distinct chatoyancy, and a lead glass-filled laboratory-grown ruby.
Micro-World
The Micro-World section, which highlights the inner world of gemstones, includes a remarkable cloudlike inclusion resembling a faceted brilliant diamond situated inside a polished diamond, a Mexican opal featuring a rare fluid inclusion with a mobile gas bubble, and a blue sapphire whose strikingly iridescent “play-of-color” along large partially healed fissures demonstrate thin-film interference typical of heat-treated corundum.
Gem News International
GNI correspondents from around the world offer a virtual report on the state of the gem and jewelry trade more than a year into the COVID-19 global pandemic. Other highlights include a geode with a striking resemblance to the Cookie Monster character, a historical hand-drilled briolette diamond, and a stunning photo gallery from the collection of the Alfie Norville Gem and Mineral Museum in Tucson, which reopens in 2021.
The Spring issue also contains the 2021 Gems & Gemology Challenge. Score 75% or better and you’ll receive a certificate of completion (PDF file); earn a perfect score and your name will be listed in the Fall 2021 issue. Online entries for the Challenge must be submitted by Monday, August 2, 2021. @chapter:54 @chapter:4 @chapter:54


# Publication Year: 1994
# Title: The Anahí Ametrine Mine, Bolivia
# Abstract: The Anahí mine, Bolivia, has produced large amounts of amethyst, citrine, and amethyst-citrine for the gem market. Field and experimental investigations conclusively show that the amethyst-citrine color combination in quartz crystals from Anahí is natural and does not result from laboratory treatment. The unusual color patterns probably result from the uncommon geologic conditions under which these quartz crystals formed, although the crystal chemical properties controlling the sector color zoning still elude explanation. From 1989 to the present, more than 100 tons of ametrine crystals, yielding 40-80 kg of cutting rough per ton, have been produced. @chapter:2 @chapter:0 @chapter:2


# Publication Year: 2023
# Title: Plastic Imitations of Emerald
# Abstract: Figure 1. An imitation emerald in the form of a chess knight measuring approximately 35.05 mm in height. Photo by Kristin Reinheimer.

Figure 2. A closer look at the knight’s head (left, in daylight) reveals the material’s aggregate structure when viewed under long-wave ultraviolet light (right). Photos by Emily Jones.
GIA’s New York laboratory recently examined two imitations, each submitted for an emerald identification report, that might have been convincing to the untrained eye. One was a chess piece weighing 46.55 ct (figure 1). At a glance, the knight appeared to be carved emerald with remnants of metallic yellow “matrix” still intact. However, the low heft and relatively warm feel of the piece suggested otherwise. Microscopic examination revealed an aggregate structure composed of jagged blocks, clearly illustrated under long-wave ultraviolet light due to its marked whitish fluorescence, typical of plastic (figure 2). The presence of gas bubbles and bluish dye concentrations indicated that the material was in fact an assemblage. The lack of a polished surface prevented a refractive index reading. Infrared and Raman spectroscopy were used to identify the main component as plastic; no beryl was detected. The metallic yellow crystal fragments were identified as pyrite, consistent with matrix associated with natural emeralds, notably those from Colombia.

Figure 3. An assemblage of plastic and various minerals imitating rough emerald in matrix, measuring approximately 51.79 mm in height. Photo by Michele Wong.

Figure 4. Gas bubbles and bluish green dye concentrations indicate that this “crystal” is in fact a manufactured product. Photomicrograph by Abadie Ludlam; field of view 8.23 mm.
The second imitation emerald (figure 3) was in the form of an elongated hexagonal “rough” emerald crystal embedded in a “matrix” of white and metallic yellow crystals, with a total weight of 179.71 ct. It too appeared natural to the unaided eye, but microscopic examination quickly distinguished the specimen as an imitation. The “emerald” portion of the rough contained large gas bubbles as well as bluish green dye concentrations (figure 4), an overall blotchy color appearance, and parallel surface striations. This material was identified as plastic using Raman and infrared spectroscopy. The surface striations were presumably created in the mold or carved to resemble the texture of a rough emerald crystal. Raman spectroscopy revealed that the smaller crystals mixed into the plastic were quartz and beryl. The white portion of the “matrix” was identified as calcite and the metallic crystals as pyrite, making this piece another convincing imitation of Colombian emerald.
The natural materials incorporated into these mostly plastic manufactured products might lead some astray upon first inspection. These two pieces demonstrate the need for a deeper inspection of all materials, regardless of how genuine they may seem on the surface. @chapter:10 @chapter:0 @chapter:10


# Publication Year: -
# Title: Update on "Low-Temperature" Heat Treatment of Mozambican Ruby: A Focus on Inclusions and FTIR Spectroscopy
# Abstract: High-temperature heat treatment has long been the most widely used method for improving the color of corundum. Soon after Mozambique emerged as an important source of rubies in 2009, it was discovered that these stones reacted well to a lower-temperature heating process.

GIA's Bangkok laboratory recently performed heat treatment experiments on 47 Mozambican rubies mined in Mugloto (Montepuez area) and observed the changes that occurred after known conditions of temperature and duration. The results are available in a new study titled "Update on ‘Low-Temperature’ Heat Treatment of Mozambican Ruby: A Focus on Inclusions and FTIR Spectroscopy.”

The experiments showed that the blue component could be reduced at fairly low temperatures and improve the color to a purer red (changing from purplish red to red). While heat treatment is difficult to detect in Mozambican rubies, a combination of inclusion study and FTIR spectral analysis gave consistent and accurate results. @chapter:10 @chapter:0 @chapter:10


# Publication Year: 2019
# Title: Book Review: Masterpieces in Miniature: Engraved Gems from Prehistory to the Present
# Abstract: By John Boardman and Claudia Wagner, hardcover, 304 pp., illus., publ. by Philip Wilson Publishers, London, 2018, US$72.00.

Gemstone engraving, also known as glyptic art, is considered to be one of the oldest crafts. Engraved stones were used to record ownership and signature as seal stones, a practice that continues today. Their use eventually extended to adornment within jewelry and decoration. The ancients valued engraved gems, both in intaglio and cameo forms, and recorded important events, people, and mythical and religious scenes on them. The artistry and skill required for the production of engravings were exceptional, considering the ancients did not have magnification. Later, during the Renaissance and Neoclassical periods, the appreciation and almost obsessive collection of these gems was a trend of the European elite. This resulted in the revival of engraving art, which typically copied the classical subjects and added the engraver’s interpretation. These collections of the 16th and 17th centuries are the basis of significant museum collections today.
Masterpieces in Miniature: Engraved Gems from Prehistory to the Present presents an exquisite private collection of engraved gems assembled almost a century ago by a notable ancient art expert. The pieces are derived mainly from older, previously unpublished European collections. The book covers a wide range of engraved gems, from the Greek Bronze Age to the Classical, Hellenistic, Graeco-Roman, and Roman eras, and then delves into gems engraved as late as the 18th century CE. The last chapter includes 12 engraved metal rings. The book was written in association with the Beazley Archive of the Classical Art Research Centre, Oxford University, which offers a large selection of resources for ancient gem studies.
This volume is beautifully illustrated and superbly written. In clear, scholarly language, the preface explains the history and challenges of glyphic art and unfolds the materials, geographies, and cultural aspects of engraved gems era by era. The preface gives excellent insight and necessary education before the reader indulges in the detailed images and backgrounds of the 251 pieces.
The reader will appreciate the authors’ examination of the subject from both academic and collector perspectives, as would a modern gem collector or gemologist. However, from a research gemologist’s point of view, the book provides great examples of the nomenclature issues we face on a daily basis that are ingrained in the historical studies, and it will take some time for scientists in history and archaeology to embrace modern gemological terminology. To be precise, a number of engraved gems are identified with old terminology, such as “plasma” or “hyacinthine [sic] garnet,” where they could easily be identified more unambiguously by a trained gemologist. It is even more puzzling, yet pleasing, to see identifications of “chromium chalcedony,” a term specific to chromium-colored chalcedony that requires particular gem-testing methods to identify. Very few gemologists conduct research on ancient gems, but the number is increasing. A noteworthy publication such as this one would benefit from a multidisciplinary approach to attract and fascinate more readers with different backgrounds.
Masterpieces in Miniature: Engraved Gems from Prehistory to the Present is a masterpiece itself and highly recommended to any gem enthusiast, even those not previously captivated by ancient gems. Collectors, historians, and connoisseurs alike will be delighted by this volume. @chapter:28 @chapter:2 @chapter:28


# Publication Year: 1990
# Title: Gem Localities of the 1980s
# Abstract: The 1980s saw major developments in new sources for diamonds and colored stones, as well as expanded production at many existing mines. This article identifies important new discoveries, as well as localities that were major gem producers, during the decade. Brief descriptions are provided for many of these, and their impact on the jewelry industry is reviewed. The article also provides an index to key recent publications on these occurrences. @chapter:34 @chapter:3 @chapter:34


# Publication Year: 2023
# Title: Etch Features Reveal the Morphology of Diamond
# Abstract: Figure 1. Table (left) and pavilion (right) views of a chameleon diamond with visible trigons and tetragons. The trigons and tetragons are shown in more detail in figures 2 and 3. The diamond measures 1.28 cm in length. Photo by Adriana Robinson.
Natural monocrystalline diamonds formed in the earth’s mantle have two major growth forms: octahedron and cube. It has been suggested that diamond growth habit depends on multiple factors, including crystallization temperature, growth rate, and the degree of carbon supersaturation in the diamond-forming fluids (J.W. Harris et al., “Morphology of monocrystalline diamond and its inclusions,” Reviews in Mineralogy and Geochemistry, Vol. 88, No. 1, 2022, pp. 119–166). If a diamond forms under changing conditions, it might not have a regular octahedral or cubic morphology but a combination of both. In some cases, diamonds grow without any well-defined crystal faces and are referred to as “irregular diamonds” (see examples in R. Tappert and M.C. Tappert, Diamonds in Nature: A Guide to Rough Diamonds, Springer-Verlag, Berlin, 2011, p. 28). While octahedral or cubic faces cannot always be identified visually in irregular diamonds, the morphology can be inferred by etch features left on the diamond by fluids in the mantle or during kimberlite eruption. Trigons and tetragons are the most common of these etch features—restricted to octahedral and cubic crystal faces, respectively.

Figure 2. Flat-bottom and pointed-bottom trigons (surface features restricted to an octahedral crystal face) preserved on an unpolished portion of the diamond. A circular etch pit overprinting a pointed-bottom trigon indicates a late-stage diamond dissolution event that postdated the formation of the trigon. Photomicrograph by Matthew Hardman; field of view 1.26 mm.

Figure 3. Tetragons (surface features restricted to the cubic crystal face) preserved at the culet of the diamond. Photomicrograph by Matthew Hardman; field of view 1.26 mm.
The Carlsbad laboratory recently examined a 2.00 ct Fancy brown-greenish yellow diamond with both trigons and tetragons on its surface (figure 1). The trigons were located within a small indented natural near the table facet, while the tetragons were preserved within an indented natural at the culet (figures 2 and 3). Co-occurring trigons and tetragons are very uncommon and indicate an irregular morphology, characterized by both octahedral and cubic growth.
This stone was identified as a chameleon diamond. For such a classification, the diamond must include a green color component, show phosphorescence to short-wave UV, and change from a greenish color to a yellow or orange color with gentle heating or when kept in the dark for an extended period (C.M. Breeding et al., “Natural-color green diamonds: A beautiful conundrum,” Spring 2018 G&G, pp. 2–27). These diamonds typically have a broad visible absorption band centered at approximately 480 nm and are referred to as “480 nm band diamonds.” A study on rough yellow diamonds from Canada showed that all of those colored by the 480 nm absorption band have irregular morphology (M.Y. Lai et al., “Yellow diamonds with colourless cores – evidence for episodic diamond growth beneath Chidliak and the Ekati mine, Canada,” Mineralogy and Petrology, Vol. 114, 2020, pp. 91–103), suggesting that diamonds with the 480 nm absorption band may form under changing conditions in the mantle.
Trigons on diamond have two major morphologies: either a flat bottom or a pointed bottom (pyramidal). The type of trigon is primarily dependent on the temperature and pressure at the position where diamond dissolution occurs, as well as on the carbon dioxide and water contents in the fluid that etches diamonds. Experimental work indicates that fluids with higher carbon dioxide content tend to produce pointed-bottom rather than flat-bottom trigons (Y. Fedortchouk, “A new approach to understanding diamond surface features based on a review of experimental and natural diamond studies,” Earth-Science Reviews, Vol. 193, 2019, pp. 45–65). Both forms of trigons were observed on the chameleon diamond we examined, as well as a circular etch pit overprinting a pointed-bottom trigon (figure 2). Unlike pointed-bottom trigons, circular pits are typically created by fluids with low carbon dioxide contents, indicating a late-stage etching event after the formation of the trigon.
The combination of surface features provides clues for the morphology of diamonds in rough form, as well as the interactions between diamonds and fluids throughout their journey from mantle residence to the earth’s surface. @chapter:41 @chapter:1 @chapter:41


# Publication Year: 2015
# Title: Yellow HPHT-Processed Rough Diamond
# Abstract: Figure 1. This 2.47 ct rough diamond was HPHT processed to improve its color. Unlike conventional HPHT-treated diamonds, this stone has a natural-looking surface. Photo by Jian Xin (Jae) Liao.

High-pressure, high-temperature (HPHT) annealing is a very effective method for changing the color of diamonds, particularly those with an undesirable brownish color. This treatment process has been practiced in the trade for more than 15 years. An important feature of this treatment is the etching often left behind on the diamond surfaces. Recently, one loose yellow diamond rough, weighing 2.47 ct and measuring 7.09 × 6.59 × 5.46 mm, was examined in the New York lab (figure 1). Without magnification, the rough had a vibrant yellow color and an overall clean-looking surface. Closer microscopic observation showed a very slightly etched surface, as well as some altered graphitized crystal inclusions in the diamond. Distinctive fluorescence reactions to long- and short-wave ultraviolet radiation similar to those of HPHT-processed material were observed, with a medium chalky bluish green under long-wave and medium to strong greenish yellow under short-wave UV. This was suspect, and further testing was needed. UV-Vis-NIR and mid-IR spectroscopy revealed the rough diamond to be HPHT processed.

The UV-Vis-NIR spectrum, seen in figure 2, showed a rise in absorption from 500 nm, associated with strong H3 (503 nm) and H4 (496 nm) peaks, along with a sharp H2 (986 nm) peak. These are indicative of HPHT treatment. Mid-IR spectroscopy (figure 3) revealed peaks at 1170 and 1332 cm–1, indicating that the starting material of this diamond appeared to be type IaB. The high temperature and high pressure of the treatment created isolated nitrogen with a corresponding absorption peak detected at 1344 cm–1. Occurrence of isolated nitrogen in a pure type IaB diamond is a strong indicator of HPHT treatment.

Figure 2. The yellow rough’s UV-Vis-NIR spectrum, showing H2 (986 nm), H3 (503 nm),
and H4 (496 nm) peaks, indicates HPHT treatment.

Figure 3. Mid-IR spectroscopy revealed an absorption peak at 1344 cm–1, indicating the
presence of isolated nitrogen. This occurrence and corresponding peak are characteristic
of HPHT processing.
The majority of HPHT-treated rough diamonds have severely burned, etched, and pitted surfaces. This is the first time we have seen an almost eye-clean yellow rough post-HPHT treatment. With new technologies available to diamond merchants, HPHT processing techniques are becoming more sophisticated, allowing for the retention of carat weight during the cutting process. This case serves as a clear reminder that buying rough does not assure a lack of treatment. @chapter:9 @chapter:1 @chapter:9


# Publication Year: 2020
# Title: Unknown Dendritic Inclusions in Sapphire
# Abstract: Left: When the pinkish purple sapphire was viewed under darkfield illumination, the only inclusions visible underneath the table were zircon crystals and rutile needles. Right: Examining the same area with fiber-optic light revealed unknown dendritic inclusions. Photomicrographs by Ezgi Kiyak; field of view 2.90 mm.
The authors recently examined a 4.03 ct light pinkish purple unheated sapphire. When viewed under darkfield illumination, the inclusion scene at first seemed fairly vacant and occupied only by sparse zircon crystals and rutile needles (see above, left). However, microscopic observation with fiber-optic light revealed large, delicate dendritic inclusions underneath the table (see above, right) that resembled a fern frond. The dendritic inclusions seemed to be flat and parallel to each other and extended the entire length of the table. Small round platelets were associated with the “branches” of the inclusions.
Further examination with a polariscope and conoscope helped prove that the dendritic inclusions were oriented parallel to the basal plane of the host corundum. A distinct uniaxial interference pattern was observed when viewing these inclusions from a perpendicular angle. The thinness and relative distance to the surface of the stone made it difficult to identify the inclusions with Raman spectroscopy. This is the first example of such dendritic inclusions in sapphire the authors have observed. However, a similar inclusion has been observed previously in a heat-treated blue sapphire (see Spring 2007 Lab Notes, pp. 54–55). @chapter:24 @chapter:0 @chapter:24


# Publication Year: 2020
# Title: Böhmite in Corundum
# Abstract: A large area of a foreign substance cut through on the surface of a ruby from the Montepuez area of Mozambique. This substance infilled not only this cavity but also many narrow fissures in the stone. Micro-Raman analysis identified it as böhmite. Darkfield + diffuse overhead illumination. Photomicrograph by Richard W. Hughes; field of view 3 mm.

Gemologists at Bangkok’s Lotus Gemology laboratory recently examined a large lot of rubies believed to originate from the Montepuez area of Mozambique. Microscopic examination confirmed that assessment. Many of these stones displayed features in their infrared spectra that are typical for böhmite, with a characteristic “twin peak” spectrum at ~3309 and 3089 cm–1 (figure 1).

Figure 1. “Twin peak” infrared spectrum of böhmite in the Mozambique ruby, with prominent peaks at ~3309 and 3089 cm–1.
One of the stones showed a large area cut through on a pavilion facet that appeared to be a foreign substance. A similar substance was seen in many of the fissures in the stone (top of page). Judicious use of the hot point under the microscope produced no reaction. We then moved to analyze the substance via micro-Raman. The result was böhmite, which neatly confirmed the results from the infrared spectrum.
Böhmite, AlO(OH), is a polymorph of diaspore. In corundum it is generally a secondary mineral, infilling surface-reaching openings after the host corundum has grown. @chapter:14 @chapter:0 @chapter:14


# Publication Year: -
# Title: Winter 2009 G&G Lab Notes
# Abstract: A New Chalcedony Treatment
DiamondView Indicates Treatment in Irradiated Brown-Orange Diamond
Fancy Intense Blue Type IIb Synthetic Diamond
Diamond with Flower-Shaped Cloud
Unusual Trigon-Shaped Clouds Indicate Two Diamonds Cut from the Same Piece of Rough
Colorless Cat’s-Eye Phenakite
Blue Sapphires Diffusion Treated with both Titanium and Beryllium
Interesting Inclusion Aggregate in Tsavorite
Uranium Mineral as Inclusion in Turquoise

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


# Publication Year: 2013
# Title: Ammolite: An Organic Jewel
# Abstract: This double-sided teardrop Ammolite weighs 35.68 ct and was mined from Alberta, Canada. Photo by Robert Weldon, © GIA.

              Ammolite popularity has grown over the past decade, since renowned feng shui master Edward Kui Ming Li began extolling its virtues to his followers. Said to promote the flow of “chi” throughout the body, enhance well-being, and reduce toxins, Ammolite can exhibit up to seven colors—each said to bring a certain benefit, such as wealth, wisdom, health, growth, or energy. Feng shui practitioners call it the “seven-color prosperity stone.”

	Ammolite is cut from rough ammonite fossils such as this specimen. Photo by Maha Tannous, © GIA
“Ammolite” is the trade name referring to gems cut from fossilized ammonite, an extinct group of marine invertebrate, also collected as whole specimens. Korite International Ltd., which began as Korite Gems in 1977, is the primary company mining, fashioning, and marketing the world’s Ammolite. The company is located in Calgary, Canada, and mines for ammonite near Lethbridge, in the province of Alberta. While the ammonite deposit was first recorded in 1908 by a National Geographic survey, local lapidaries of Calgary only started fashioning Ammolite in 1962—which is hard to believe since lapidaries are always looking for new and unique materials to cut.

Author Stuart Wilson was recently given a tour of Korite International by company president Pierre Pare. He documented the experience, which included a visit to the mine site, in his June 2013 Rock & Gem article, “Ammolite: An Organic Jewel.” The article offers a thorough overview of Korite’s operation and how these fragile shells are mined, an excavation process that often occurs at depths of 50 to 60 feet.

Unlike the vast majority of ammonite deposits found around the world, the specimens found at Korite’s mine site have a fossilized outer shell that’s iridescent as a result of replacement by aragonite. The iridescent phenomenon in Ammolite arises from the interference of light bouncing off stacked layers of thin microscopic platelets that make up the replaced aragonite in the ammonite shell. According to the article, the gem can be found along the east side of the Rocky Mountains, but this is the only economically productive area of gem-quality Ammolite in the world.

	Natural Ammolite is typically impregnated with a polymer to stabilize the thin surface layer and bring out the iridescent colors, as shown in this specimen. Photo by Maha Tannous, © GIA
Five 10-gallon buckets of ammonites are extracted weekly from the shale pit where they are found. Approximately five acres are mined annually, utilizing two excavator machines working in different areas, and a spotter who stands near each one, looking for any ammonite that becomes exposed. Ammonites may be found at any level, but the deeper the excavation, the more expensive the overall process.

Because ammonite shells are fragile, the weight of thousands of feet of sediment cracked most of them during fossilization. Whole, unblemished specimens without fractures are found, however, and their rarity is reflected in their high price. Because of their fragility, Ammolites are most often fashioned into triplets consisting of an Ammolite layer with its original shale backing, and a synthetic spinel or quartz cap. Only about 100 solid Ammolite stones are cut annually. A large percentage shows a green-red color shift due to a more stable, thicker layer of aragonite. The blues and violets are rarer due to the fragility of the thinner layers necessary to produce these colors.

Korite International has come up with a logical grading system that has been accepted by the international gem community. In stones that are “AA” or “exquisite,” the highest quality, three or more brilliant colors must be evident. Only 3−8% of Korite’s annual production meets this grade. “A+” or “extra fine” grades display three or more brilliant colors with less-brilliant areas. “A” or “fine” material has one or more colors, with either one that is brilliant or three that are less brilliant than those in the “A+” class. “A-”  or “standard/good” comprises approximately 40% of Korite’s annual production and is characterized by Ammolite that shows mostly shades of green or red that are strong but less brilliant than the preceding grades. “B” or “fair” material displays one or two colors of fair brilliance. These stones are generally set in silver, as gold settings are reserved for the higher Ammolite grades. “C” or “commercial” quality material applies to only 5−10% of annual production and displays faint color patches or has unattractive fracture patterns.

	From left: This photo exhibits three phases of Ammolite: rough, cut stones, and a “Kabuki” brooch. The brooch, courtesy of and designed by Carolyn Tyler, includes Ammolite fashioned with a 1.23 ct tsavorite, 1.40 ct garnet, and .96 ct blue tourmaline, set in 22K gold. Photo by Orasa Weldon, © GIA
Production has been consistent, despite being hindered by permafrost in the winter. While the article doesn’t shed new light on Ammolite, it provides a good overview of the stone, which has seen an increase in sales. The Chinese market has been particularly significant to Korite’s success, according to the article, as Asian collectors tend to appreciate phenomenal stones. @chapter:4 @chapter:0 @chapter:4


# Publication Year: -
# Title: Hong Kong Jewelry Show: The World’s Largest Assemblage of Cultured Pearls
# Abstract: More than 1,200 metric tons of freshwater cultured pearls were produced in China in 2011. Buttons, rounds, semi-rounds, and lower-quality dyed pearls at this Chinese wholesaler's booth at the 2012 Hong Kong Jewelry Show are typical of that production. Photo by Russell Shor

                      Cultured pearls are farmed all over the Pacific Rim and the rivers and lakes of China. Regardless of origin, the vast majority—South Sea, akoya, French Polynesian black, or golden from the Philippines—are sold through Hong Kong.

	A river of cultured pearls of all sizes and varieties was on display at the 2012 show, the
	largest of its kind in the world. Photo by Russell Shor.
Nowhere is that more evident than at the Hong Kong Jewellery and Gem Fair, held in mid-September each year. The show takes place in two venues, the Asia World Expo near the airport and the Hong Kong Convention & Exhibition Centre in the heart of the city, and thousands will flock to there to buy and sell once again Sept. 11–17, 2013.

	This assortment of Chinese freshwater cultured pearls shows the wide variety of sizes and colors sold at the 2012 Hong Kong Jewellery and Gem Fair. Photo by Russell Shor.
Nearly 1,000 pearl wholesalers assemble in a dedicated PearlPavilion at the Asia World Expo , which is the largest accumulation of cultured pearls in any single place. Top brands also show their finest merchandise at the Hong Kong Premier Pavilion in the convention center. Many of the major saltwater pearl producers, including Paspaley Pearling Company and Robert Wan, auction their new goods in conjunction with the show. @chapter:53 @chapter:4 @chapter:53


# Publication Year: 2020
# Title: Spinel on Sapphire
# Abstract: Figure 1. This 4.8 cm pale blue sapphire crystal contained numerous purple spinel crystals on the surface. Photo by Angelica Sanchez; courtesy of Steve Dubyk.
Recently the authors examined a 4.8 cm tall pale blue sapphire crystal (figure 1) that featured numerous purple spinel crystals up to 8 mm in size on the surface (figure 2), a rather uncommon association. Steve Dubyk of Albuquerque, New Mexico, had acquired this specimen and doubted the accuracy of the accompanying label, indicating aquamarine from Tres Pozos in Baja California, Mexico. Raman spectroscopy confirmed Mr. Dubyk’s suspicion that the specimen was in fact corundum and identified the associated purple crystals as spinel. LA-ICP-MS chemical analysis suggested that the specimen was from Sri Lanka based on the trace elements present, which indicated an average of 130 ppma iron (Fe), 38 ppma titanium (Ti), and 37 ppma magnesium (Mg). The trace element chemistry is also notable, as the magnesium will preferentially charge compensate the titanium, leaving very little excess titanium to pair with iron to produce a blue color. The chemistry measurements were consistent with the very pale blue color observed in this stone. The chemistry of the spinel was also interesting in that its reasonably saturated purple color would indicate it was at least partially caused by chromium. However, the spinel was inert to long-wave UV light, suggesting no chromium was present. LA-ICP-MS testing confirmed the absence of chromium but showed relatively high iron (10,566 ppma) and some cobalt (2.75 ppma average) which together are likely responsible for the purple color (A. Palke and Z. Sun, “What is cobalt spinel? Unraveling the causes of blue color in blue spinel,” Fall 2018 G&G, p. 262). While spinel is uncommon in sapphire, a spinel inclusion has been previously reported in a Sri Lankan yellow sapphire (Winter 2015 Micro-World, p. 444). This sapphire is one of the more unusual examples the authors have encountered.

Figure 2. Purple spinel crystals were intergrown on the outermost layer of the sapphire crystal, which appears to be from Sri Lanka based on trace element chemistry. Photomicrograph by Nathan Renfro; field of view 13.42 mm. @chapter:24 @chapter:0 @chapter:24


# Publication Year: 2022
# Title: Fifth Annual Gianmaria Buccellati Foundation Award Winner
# Abstract: The winning design from the 2021 Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design, created by Meghan Simmons, a Carlsbad graduate of the GIA Jewelry Design program.
Meghan Simmons, a graduate of GIA’s Jewelry Design program at the Carlsbad campus, received the fifth annual Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design. The award was presented at the GIA Alumni Collective’s “Night at the Museum” event held during the AGTA GemFair Tucson. One of 11 finalists, Simmons competed against more than 80 students from GIA’s seven campuses. Her winning earring design (see above), inspired by the abstract artist Wassily Kandinsky, emphasizes the use of line and shape with gold, diamonds, and blue sapphires.
Simmons will spend a week in Italy, traveling from Florence to Venice to Milan, and will meet with a representative from the foundation.
Larry French, chief officer of North American strategies for the foundation, said, “This competition was born out of the life and work of Gianmaria Buccellati. We congratulate not only all the students who participated in this year’s design competition but also the talented instructors from GIA who guided the students on this beautiful art.”
The 2022 Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design competition is underway and open to students in GIA’s Jewelry Design courses who meet the eligibility requirements. For more information, visit gia.edu/buccellati-foundation-award-jewelry-design. @chapter:45 @chapter:2 @chapter:45


# Publication Year: 2013
# Title: Diamond with High Concentration of Nickel
# Abstract: Figure 1. This 2.54 ct Fancy Light greenish yellow diamond showed a high quantity of nickel, believed to be related to its fancy color saturation. Photo by Robison McMurtry.

A 2.54 ct cushion-cut diamond (figure 1) was color graded as Fancy Light greenish yellow. Its UV-Vis-NIR spectrum showed a large absorbance caused by nickel-related defects (figure 2). It is unusual for a diamond to be solely colored by nickel, and more so for the diamond to be graded in the fancy color range. Such diamonds have been previously reported (W. Wang et al., “Natural type Ia diamond with green-yellow color due to Ni-related defects,” Fall 2007 G&G, pp. 240–243), but this was the first time energy-dispersive X-ray fluorescence (EDXRF) spectroscopy has been run to detect the presence of nickel. As seen on the XRF spectrum (figure 3), the nickel content was high enough to be detected. This is likely related to the diamond’s fancy color saturation.

Figure 2. This UV-Vis-NIR spectrum shows an unusually large absorption band related to nickel defects in diamond.

Figure 3. The greenish yellow diamond’s EDXRF spectrum shows a clear peak at 7.5 keV, a characteristic peak of nickel.
In addition to its unusual color origin, the diamond contained a mineral inclusion with a color-change effect. It appeared purple under the incandescent well light of a gemological microscope and dark blue under the fluorescent overhead light on the same microscope. We suspected the inclusion was a color-change garnet, and this was confirmed using Raman spectroscopy. The stone also contained a small cloud of oriented reflective inclusions associated with type IaA diamonds, consistent with this sample’s diamond type. The diamond showed weak green transmission, which was unusual because it had no defects commonly associated with green transmission (i.e., the H3 feature). Whether the transmission is related to the nickel content is not known. @chapter:22 @chapter:1 @chapter:22


# Publication Year: 2015
# Title: Two Large Natural Pearls Reportedly from Spondylus and Trochoidea Species Mollusks
# Abstract: Figure 1. Left: A large natural pearl reportedly from a Spondylus species. Right: A large natural pearl reportedly from a Trochoidea species. Courtesy of Sunghee Caccavo.

In a Fall 2014 Lab Note (pp. 241–242), GIA reported on four natural pearls ranging from 5.72 to 12.40 ct that were reportedly from a Spondylus (thorny oyster) species. These interesting non-nacreous pearls showed porcelaneous surfaces with unique bluish flame structures. Another even larger natural pearl, also reportedly from a Spondylus species, was recently submitted to the New York laboratory for identification. This pearl measured approximately 24 × 16 mm and weighed 42.96 ct (figure 1, left). It was formed in an attractive drop shape with a homogeneous yellow-brown bodycolor, abundant surface grooves, and a distinct bluish flame structure (figure 2). As with previous examples, microradiography showed only a tight structure, lacking obvious growth arcs. In addition, aragonite and natural polyenic pigment peaks were detected by Raman spectroscopy. Its unique appearance, coloration, and bluish tinted flame structures consistent with Spondylus pearls we previously reported. There is no known cultured pearl from this species, and the tight structure is commonly seen in other non-nacreous pearls, which further confirmed its natural origin.

Figure 2. Distinct bluish flame structures were observed on this large non-nacreous pearl, similar to previously studied samples that also reportedly formed within Spondylus (thorny) oysters. Photo by Joyce Wing Yan Ho; field of view 7.9 mm.

	The same client also submitted a large natural nacreous pearl reportedly from an unknown Trochoidea (turban snail) species (figure 1, right). The specimen, which measured approximately 27 × 19 × 12 mm and weighed 39.30 ct, had a cream color, high luster, and strong orient. Its smooth surface showed a unique wavy pattern. Previously GIA reported on a natural pearl from the turban snail species Astraea undosa that also showed high luster and strong iridescent colors, with an undulating wave-like pattern (Winter 2003 GNI, pp. 332–334). Both pearls share many common characteristics, and their appearances closely resemble one another.

	Our client claimed that the Spondylus pearl is from Baja, Mexico; the turban pearl is from Mexico’s Pacific coast. Although it is extremely challenging to identify the exact mollusk species these rare pearls originated from, their unique and interesting appearances are consistent with previously studied materials of similar claims. Regardless of their exact origin, these beautiful large natural pearls prove just how wonderful Mother Nature is at creating spectacular wonders of great variety and eye-pleasing form. @chapter:11 @chapter:4 @chapter:11


# Publication Year: 1981
# Title: Irradiated Topaz and Radioactivity
# Abstract: A parcel of 100 stones of deep blue irradiated topaz, imported from Brazil, was found to be radioactive at a level somewhat higher than typical background activity. Analysis indicates that the material had been treated by neutrons in a nuclear reactor. Most irradiated topaz in the trade is not radioactive. Nevertheless, routine testing for radioactivity in topaz, beryl, green diamonds, red tourmaline, and possibly all gemstones may be advisable for the protection of the jeweler. @chapter:27 @chapter:0 @chapter:27


# Publication Year: 2021
# Title: Unusual Fluorescence of a Color-Enhanced Amber Bracelet
# Abstract: Figure 1. This bracelet contained amber (approximately 10 mm each) that was color-enhanced by a baking process. Photo by Yu-Shan Chou.

              Heat treatment is commonly applied to amber, mainly to improve its color or transparency. The method of heat treatment to enhance the color of amber is informally called a “baking process,” which refers to the process of heating while applying pressure and adding oxygen (Y. Wang et al., “Experimental studies on the heat treatment of Baltic amber,” Summer 2014 G&G, pp. 142–150). Usually, the light yellow amber will be darkened and turned brownish yellow or brownish red by such a process to increase its market value. Amber may also be heated to produce sun spangles and sold as “flower amber” for its popular demand in the market.

A bracelet recently sent to Taiwan Union Lab of Gem Research (TULAB) for identification services contained amber that was pale brownish yellow, transparent, and slightly included (figure 1). Raman spectroscopy and microscopy confirmed the gems to be natural amber with an abundance of sun spangles, which were discoidal fractures caused by heat treatment.

Color enhancement of amber is generally not detectable unless the amber itself has cracks or pores extending to the surface during the baking process, in which case the color usually concentrates in these cracks and pores. Apart from that, amber that is color-enhanced by the baking process mostly shows inert or faint yellow fluorescence under long-wave ultraviolet light; however, such fluorescence may also occur in natural untreated amber.

Figure 2. Magnification revealed that the dark brown color was concentrated in the surface-reaching fractures or sun spangles, yet the sun spangles or fractures wrapped inside the amber were all yellow. Photomicrograph by Shu-Hong Lin.
Microscopic observation of the amber bracelet revealed that the dark brown color was concentrated in all the surface-reaching fractures or sun spangles, but the sun spangles wrapped inside all appeared in a lighter tone of yellow (figure 2). Thus, it was suspected that this amber bracelet had been baked to enhance color.

In addition to the inclusion evidence, the amber bracelet’s long-wave ultraviolet fluorescence reaction unexpectedly presented a relatively bright blue along the ridgelines and inert to faint yellow on the rest of the stone (figure 3).

Figure 3. Under long-wave ultraviolet light, the amber bracelet presented a surprising bright blue fluorescence on the ridgelines and inert or faint yellow fluorescence on the other parts. Photo by Kai-Yun Huang.
This abnormal fluorescence strongly indicated that the amber had indeed been baked to enhance its color and that the ridgelines were worn due to grinding or wearing, which removed the brown surface layer.

This case is worthy of attention because a series of similar items have subsequently been submitted for identification. Traditionally, the color enhancement of amber has been confirmed only by inclusion evidence; however, the abnormal fluorescence of this object offered supporting evidence. @chapter:46 @chapter:4 @chapter:46


# Publication Year: 2022
# Title: Small “Surprise” in Elbaite Tourmaline
# Abstract: The “exclamation point” inclusions were identified as diopside crystals using Raman spectroscopy. Photomicrograph by Shu-Hong Lin; field of view 4.11 mm.
Recently, a 0.86 ct orange-yellow elbaite tourmaline cabochon was submitted to Taiwan Union Lab of Gem Research (TULAB) for identification service. The stone contained many prismatic and round xenocrysts. Among these inclusions was a prismatic crystal associated with a round crystal, a composition resembling an exclamation point (see above). The crystals were later confirmed to be diopside using Raman spectroscopy. Darkfield illumination, plane polarized light, and extended depth of field were adopted to obtain a clear microscopic image of this little “surprise” inside the gemstone. @chapter:15 @chapter:0 @chapter:15


# Publication Year: 2001
# Title: Spectral Reflectance and Fluorescence Characteristics of Natural-Color and Heat-Treated “Golden” South Sea Cultured Pearls
# Abstract: A comparison study was made between the yellow and white nacre of the gold-lipped Pinctada maxima oyster shell and 65 yellow cultured pearls, both natural and treated color, produced from this mollusk. The yellow nacre of this shell has a characteristic absorption feature in the UV region between 330 and 385 nm; the strength of this feature increases as the color becomes more saturated. White shell nacre fluoresces very light blue or very light yellow to long-wave UV radiation, whereas yellow shell nacre fluoresces greenish to brownish yellow or brown. Natural-color yellow cultured pearls from P. maxima exhibited absorption and fluorescence characteristics similar to those of the yellow shell nacre. In contrast, the absorption feature in the UV was either weak or absent in yellow cultured pearls reportedly produced by a method involving heat treatment, and their fluorescence was generally very light blue or light yellow. @chapter:11 @chapter:4 @chapter:11


# Publication Year: -
# Title: Peridot Care and Cleaning Guide
# Abstract: With a little care, peridot will make a fine gemstone for jewelry. - © GIA & Tino Hammid, courtesy 23rd St. Shoppe, Santa Monica

Hardness and toughness
Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease or difficulty with which one mineral can be scratched by another. But the Mohs scale is deceptive. The steps between the minerals are not evenly spaced. For example, diamond is only one number away, but it’s many times harder than gems in the corundum family.

	Peridot rates 6.5 to 7 on the Mohs hardness scale.
Peridot is 6.5 to 7 on the Mohs scale. It has fair to good toughness. Peridot is durable enough for jewelry wear but should be worn with some care so as not to scratch it or subject it to hard blows that can fracture it.

Stability
Rapid or uneven heat can cause peridot to fracture. Peridot is stable to light but is easily attacked by sulfuric acid, and less easily by hydrochloric acid. It can also be attacked over a long period of time by acid perspiration.

Cleaning
Warm, soapy water is the best method for cleaning peridot. Ultrasonic and steam cleaners are not recommended. @chapter:27 @chapter:0 @chapter:27


# Publication Year: 2014
# Title: A Glimpse into the Russian Diamond Trade
# Abstract: “New Reality of the Russian Jewellery Market,” Russian Diamonds & Jewellery, No. 1, Spring 2013, pp. 14–15.

              More than 20 years after the dissolution of the Soviet regime, published statistics about Russian diamond and gem production are still difficult to come by. This article from Russian Diamonds & Jewellery is especially welcome, even if the translation into English is difficult to follow. Among the highlights:

		The 2013 initial public offering of the Russian diamond producer Alrosa was not expected to attract other major players such as De Beers because only 14% of the company’s stock went on the block. The remainder was held by the Russian government (42.9%), the Republic of Sakha (25%), and private blocs (17%).

		Alrosa also signed a deal to supply the auction house Sotheby’s with large diamonds to market through its retail diamond division. Alrosa provided two diamonds weighing between 40 and 60 ct in the first sale of this agreement. The diamonds to be sold by Sotheby’s carry GIA grading reports.

		Russia’s largest diamond polishing operation, Smolensk Kristall, has become increasingly more active in the auctioning of polished diamond. Fifty-one of 80 lots sold for $1.9 million in the first sale, which largely consisted of diamond melee.

		Russian jewelry imports have increased in recent years. In 2012, Russia imported 89.35 million tons of gold jewelry and 285.17 million tons of silver jewelry, an increase of 6.7% over the previous year.

		Local press reports have noted an increasing problem with undisclosed synthetic or imitation gemstones, diamonds and pearls being passed as natural. @chapter:49 @chapter:3 @chapter:49


# Publication Year: -
# Title: Demantiod from the Green Dragon Mine
# Abstract: Stephan ReifSales Executive, Green Dragon Mine

Interview with Stephan Reif, Sales Executive, Green Dragon Mine
Mr. Reif came to the Tucson Gem Show to promote his mine’s product: demantoid garnet, “one of the rarest stones alive.”

His excitement is obvious as he talks about the Green Dragon Mine, located in Central Namibia. It was discovered by accident when a Namibian goat-herder stumbled on some green crystals in the dirt.

The Green Dragon is an open-pit mine, with a crushing plant and sorting house on-site. Its desert location means they have to bring in water from outside, limiting their ability to put the ore through a density separation step, which instead is performed carefully by hand. They also have to live with the desert’s punishing temperature extremes.

With no clear indication where the “good stuff” is hiding, Green Dragon miners depend on a combination of instinct and geological knowledge to find the richest pockets. Mine yield—between 5,000 and 10,000 carats—is mostly melee, small gems measured in millimeters.  Half-carat finished stones are rare; over a carat, very rare.

Turning to his stones, he shows some samples of cut demantoids, including melee rounds and a selection of larger, square-shaped brilliants. He holds them to the light to show how their color and cut are just right for displaying a lot of fire. He also has a selection of what he calls “army-colored” demantoids—sort of a brownish green—that are very popular with his clients.

The mine’s social responsibility to its workers includes a housing program: Some of what the mine earns goes into a fund to help workers and their families find proper housing. The mine is visited periodically by government and environmental regulators to check on how they treat their employees, ensure blasting safety, maintain their mining claim status, etc.

Green Dragon markets its demantoids on US home-shopping TV stations, to high-end European and Swiss consumers, and to manufacturers in Asia. This beautiful stone appeals to jewelry designers, collectors, and others who love unusual stones. You can tell by Mr. Reif’s enthusiastic tone and delivery that he’s just as excited as everyone else about its beauty and potential. @chapter:23 @chapter:2 @chapter:23


# Publication Year: 2017
# Title: Tourmaline Crystals on Burmese Ruby
# Abstract: Bluish green tourmaline crystals and white calcite on a Burmese ruby. Photo by Charuwan Khowpong; field of view 2.48 mm.

During a GIA field expedition to Mogok, Myanmar, a tiny but interesting sample was acquired. This 0.552 ct ruby was purchased from local Kanase miners who process the tailings of the larger mines in the Kyatpyin Valley, just west of the town of Mogok. The ruby is associated with pure white calcite and bluish green tourmaline (see above).

Many rubies form in marble, especially in the deposits related to the Himalayan orogeny (Afghanistan, Tajikistan, Myanmar, and Vietnam), so calcite as an inclusion or associated mineral with these gems is common. While tourmaline in combination with ruby is not unheard of, it is a relatively unusual combination. Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) chemical analysis showed that the tourmaline was a Na-Mg-rich dravite. Tourmalines are of great interest to geologists because their isotopic and trace element composition are potentially strong indicators of the formation environment of the tourmaline and the associated minerals, in this case ruby. @chapter:14 @chapter:0 @chapter:14


# Publication Year: 2023
# Title: The history of gemstones in Chanthaburi_29
# Abstract: The trade mark of Chanthaburi province is Siamese ruby, which nowadays is considered an antique gemstone, as it must be mined for at least 15 years. The distinctive feature of Siamese ruby is its red color, which ranges from a slightly purplish red to a deep red. In contrast, Burmese rubies typically have a pinkish hue. @chapter:40 @chapter:0 @chapter:40


# Publication Year: 2023
# Title: Jewelry sales have slightly decreased.
# Abstract: From data compiled by experts at the leading jewelry company SOKOLOV in Russia, it was found that during the first nine months of the year 2022 (2565 by the Buddhist calendar), the Russian jewelry market recorded a high value of 211 billion rubles. This marked a decline of 6% annually, consistent with the economic conditions in the country, including cases where some foreign brands withdrew from Russia. The average sales value per transaction increased by 16%, amounting to 6,414 rubles, with online sales accounting for 18% of total sales.
Analysts believe that the market will not contract rapidly, unlike in previous New Year periods where sales typically peak and promote sales in the autumn season. This seasonal push is expected to mitigate an annual contraction of no more than 10%.
In the first half of 2022 (2565), general spending on jewelry among Russians decreased. Experts attribute this reduction to cautious consumer spending, particularly following July's ban on gold and jewelry purchases from Russia, which started to have enforceable effects in Europe if sourced directly or indirectly from Russia.
Despite ongoing economic uncertainties, Russian consumers tend to tighten their spending immediately when economic conditions are uncertain. Luxury products deemed non-essential for livelihoods are often the first to be cut from expenditure. However, despite tensions with Ukraine stretching into the next year, overall jewelry sales this year are considered to have declined only moderately. This was aided by the easing impact of the COVID-19 pandemic, which relieved prolonged consumer demand constraints.
Additionally, international travel has become more convenient, as evidenced by several Russian importers' enthusiasm for visiting the Bangkok Gems & Jewelry Fair in Thailand in September, after a hiatus of approximately two years due to Thailand's non-organization of events. This is seen as a positive signal for Thailand's exports of gems and jewelry amid global economic fluctuations. @chapter:32 @chapter:3 @chapter:32


# Publication Year: 2017
# Title: Unusual Cloud in Diamond
# Abstract: The delicate interlinked cross-like cloud pattern found in this 0.62 ct diamond has never been encountered in GIA’s laboratories. Photomicrograph by Nathan Renfro; field of view 2.40 mm.

GIA’s laboratories issue clarity grades for many diamonds for the gem trade. So when we observe a diamond with clarity characteristics we have not encountered before, we generally consider those features to be rather rare and worth documenting for future reference.

Recently, just such a diamond was examined in the Carlsbad lab. It was a 0.62 ct round brilliant with very good polish and symmetry and a very light brown bodycolor. The diamond exhibited a faint light blue fluorescence to long-wave radiation and an inert reaction upon exposure to short-wave UV.

The gem’s I1 clarity grade resulted from a delicate cloud of cruciform dislocations (see above), forming numerous small interlinked cross-like patterns in the diamond host, which were visible face-up through the table facet. The shape and orientation of the overall cloud suggests that the cube face of the original diamond crystal was parallel to the table facet of the faceted diamond.
We regularly encounter cloud clarity features in diamonds, but this fascinating geometric network was a “first encounter” for us. @chapter:22 @chapter:1 @chapter:22


# Publication Year: 2013
# Title: Strong Color Zoning Reflects Complex Growth Environment
# Abstract: Figure 1. The strong color zoning in this Fancy Dark orangy brown diamond was visible at 10× magnification. Photo by Troy Ardon.

			A 2.08 ct emerald-cut diamond recently submitted to the Carlsbad laboratory received a color grade of Fancy Dark orangy brown. Its strong color zoning, visible without magnification, consisted of a dark orangy brown section with a few near-colorless bands and a near-colorless area. The orangy brown section showed numerous very small oriented reflective inclusions, visible in figure 1 only as dark clouds, that are typically associated with type IaA diamonds colored by 480 nm visible absorption bands. Both the near-colorless side and the colorless bands displayed very few oriented reflective inclusions.

				Figure 2. Under long-wave UV illumination at 10× magnification, the diamond’s color zones showed blue and yellowish fluorescence. Photo by Troy Ardon.

				The diamond’s unusual fluorescence under both long- and short-wave UV illumination can be seen in figures 2 and 3, respectively. Under long-wave UV (handheld lamp) the near-colorless section showed typical blue fluorescence. The orangy brown section displayed a yellowish fluorescence, which is common in type IaA yellow diamonds. Under the higher-energy, shorter-wavelength UV excitation of the DiamondView, the distinction between the colors became even more pronounced, and the blue fluorescence of the near-colorless bands was clearly visible within the yellowish green fluorescence of the orangy brown section. Yellow phosphorescence, common in type IaA diamonds colored by 480 nm visible absorption bands, was also observed in the orangy brown area.

				Figure 3. This DiamondView image of the color-zoned diamond shows an even more pronounced distinction between the colors. Image by Troy Ardon.

				Infrared spectroscopy revealed a type Ia diamond with both A and B aggregates. When IR spectra were collected separately from the near-colorless and orangy brown sections, distinct differences were noted. The orangy brown section contained ~33 ppm of A-aggregated nitrogen and ~15 ppm of B-aggregated nitrogen, whereas the near-colorless section showed significantly higher concentrations: approximately 139 ppm of A aggregates and 100 ppm of B aggregates. In addition to the higher overall nitrogen content, the near-colorless portion contained a higher proportion of B-aggregated nitrogen impurities.

				The unique zoning observed in this diamond likely reflects changing conditions during growth. Variations in nitrogen and possibly oxygen content in the earth’s interior—480 nm defects are reportedly related to oxygen impurities in diamond—could have produced the noteworthy color and fluorescence zoning that reveal the complex growth history. @chapter:22 @chapter:1 @chapter:22