Publish Year: - Title: Morganite Quality Factors Abstract: Mention of the name morganite immediately brings to mind beautiful pastels of pink, purplish pink, and orangy pink. - Robert Weldon, courtesy Mayer & Watt, Maysville, Kentucky

                      Morganite is known primarily as a pastel-colored gem in light, soft shades of pink, purplish pink, and orangy pink. Although light tones are normal for morganite, some stones display strong color.

Color
Morganite’s color range includes pink, rose, peach, and salmon. In today’s market, the pink and rose tints are more fashionable. The peach and salmon hues seem less popular, but some collectors value untreated peach-colored material more highly than heat-treated pink stones.

The gem is almost always heat-treated to improve the pink color. The treatment is not detectable. Heat drives off the yellow or orange tinge, leaving a purer and more attractive pink. The resulting color is stable and won’t fade.

	This skillfully fashioned morganite has the salmon-to-peach color typical of untreated material. - John Dyer, gem courtesy of John Dyer & Co.

	At 68.38 cts., this morganite is large enough to display an attractive pinkish purple color. - Robert Weldon

	Like aquamarine and green beryl, morganite’s color is often light in tone. - Eric Welch

	Light-toned and peach-colored would be an easy way to describe this pastel orange-pink morganite. - Robert Weldon
Clarity
Like aquamarine, another beryl variety, faceted morganite usually does not have inclusions that are visible to the eye. Less-transparent material is often carved or cut as cabochons.

	Most faceted morganites do not have inclusions that are visible to the eye. - Robert Weldon
Cut
Because morganite has distinct pleochroism—pale pink and a deeper bluish pink—it’s necessary to orient the rough carefully for fashioning. Strong hues in morganite are rare, and gems usually have to be fairly large to achieve the finest color. Morganite is cut in all standard shapes and sizes as well as in unique designer cuts.

	Morganite is cut in standard as well as custom shapes and cutting styles, and comes in all sizes. - Robert Weldon

	As with most gems, matched pairs of fashioned morganite command a substantial premium. - Robert Weldon, courtesy Omi Gems.

	This 50.92-ct. designer-cut morganite’s facets and proportions are designed to bring the greatest possible life out of the stone. – Lydia Dyer, gem courtesy of John Dyer & Co.
Carat Weight
Morganite crystals can be very large, so large faceted stones are more common than with many other gemstones. Larger sizes are also more likely to show strong color.

	Morganite crystals are sometimes very large. - Brendan Laurs

	Faceted morganites can be found in large sizes, even exceeding 100 cts. - Robert Weldon @topic:2


Publish Year: - Title: Women of GIA: A Portrait of Three Innovators Abstract: Since Robert and Beatrice Shipley formed GIA in 1931, the Institute has relied on the commitment and drive of its employees: No resource has enriched the Institute more than the men and women who walk its halls.

When GIA began, however, few could have anticipated the mark women would make on its future. According to the 1930 U.S. Census, only 22% of American women over the age of 10 worked outside the home. Of those, more than one-third were employed in “domestic and personal service.” Even during the Great Depression, women were not expected to pursue employment in professional positions, or to stay in the workforce once married.

Bucking such trends since its beginnings, GIA has always welcomed and encouraged the contributions of women to advance gemology, whether in the lab, in business operations, or in publishing. In this way, the Institute has been ahead of the curve in cultivating the trailblazing aspirations and achievements of women.

Here we honor three women whose contributions ultimately changed the course of GIA’s history.

	Beatrice Shipley: The “Backbone” of GIA

	Beatrice Shipley (1888-1973); photo © GIA.
Robert Shipley may have ignited the spark that created GIA, but his dream could never have survived its first few years without the emotional, financial, and managerial support of his wife and business partner, Beatrice Shipley. Their chance meeting in 1928 at the Louvre in Paris led to a 43-year marriage and a revolutionary change in the field of gemology. Her background in management, education, and administration, as well as her fiscal acumen, helped the Institute get through the Depression years while her husband traveled around North America to spread interest in GIA’s programs. An employee who worked during those difficult years said that Beatrice Shipley was “the backbone, the one that kept GIA going and made it a success.”

Beatrice Woodell Bell, a divorcée who was no stranger to hardship or practicality, worked as an administrator for the Episcopal Church and as dean of the exclusive Marlborough School for Girls in Los Angeles. Upon her marriage to Robert Shipley in 1930, she ran a small art gallery while her new husband developed his plans for a comprehensive gemological training program. Initially skeptical of this endeavor, she nonetheless threw her entire support behind her husband, closing her art gallery in 1932 to manage GIA’s day-to-day affairs.

Working under the name “B.W. Bell” to disguise both her female identity and her connection to Robert Shipley, she implemented standards, protocols, and budgets, while creating and maintaining a professional business environment. During lean years, she kept payroll running and morale high, yet was never afraid to do the most basic tasks, even assembling and stapling course materials before they were mailed to students.

In addition to her office work, she gave speeches to women’s groups on gems and jewelry. In one such presentation to the mothers of Hollywood stars such as Rosalind Russell, Gary Cooper, and Cesar Romero, called “Gems & Personalities,” Mrs. Shipley explained the properties of each gemstone and, based on physical appearance, paired each celebrity mother with a flattering gemstone. Talks such as these brought GIA to a mainstream audience, attracting ever more attention to the Institute’s gemological work.

Largely due to the Shipleys’ efforts to establish a sister organization as a professional guild for jewelers, the American Gem Society (AGS) was established in 1934 with Mrs. Shipley serving as its chief administrator.

Beatrice Shipley retired from both GIA and AGS in 1943, eventually serving as president of the Los Angeles Girl Scout Council. Her devotion to the advancement of gemology never wavered, however, and she remained an advisor to her husband on Institute matters throughout her life. After her death in 1973, she was lauded throughout the gemological industry as a pioneer in the field, recognition that was hard-earned and well deserved.

	Eunice Robinson Miles: “Mother GIA”

	Eunice Miles (1917-1997); photo © GIA.
Thanks to her grandmother’s gemstone and mineral collection, Eunice Miles (née Robinson) developed a passion for gems as a child. It was a natural progression for her to pursue a degree and career in the field of gemology. In 1953, Miles made history as the first female gemologist at GIA’s laboratory. Her time at the Institute yielded groundbreaking research and dynamic lectures that influenced students and colleagues alike, earning her the nickname “Mother GIA” from no less than Richard Liddicoat.

The only female student in her classes at MIT, Miles earned a Certified Gemologist (C.G.) diploma from GIA in 1944. She lectured extensively on gemological topics, even appearing on television, before joining the lab in New York, where she remained for 15 years. While Miles quickly earned the respect of her co-workers when they saw her abilities in action, dealers and other members of the trade proved more challenging. She was mistaken for the lab’s receptionist, and was at one point told, “You are a woman! What can a woman know about diamonds?”

A great deal, it seems. Miles later pioneered research into diamond-coating techniques and identification. Her work was recognized by the U.S. Department of Mines, and was ultimately used by the FBI to apprehend a dealer in fraudulently coated diamonds. Her initials on diamond grading reports upheld the Institute’s reputation for excellence.

In addition to her work in the lab, Miles served the Institute as a lecturer, instructor, and career counselor, creating rapport with students and building relationships that lasted decades. Upon her retirement, she became GIA’s official historian, a position she held until her death in 1997.

By the time of her retirement, Eunice Miles’ influence on the field of gemology was widely recognized. She was the recipient of numerous awards, including an Honorary Fellowship from the Gemmological Association of Great Britain, the Hall of Fame Award from the Women’s Jewelry Association, and the International Society of Appraisers Gems and Jewelry Industry Service Award. In 1986, the Association of Women Gemologists named their Lifetime Achievement Award after Miles, the inaugural recipient. Her gemological work still influences students today, both in the field of research and through the GIA scholarship established in her name, awarded to Institute students annually since 1989.

	Alice Keller: “Stalwart Guardian of G&G”

	Alice Keller; photo by Eric Welch, © GIA.
Readers of today’s Gems & Gemology can see the influence of Alice Keller on every page.

Part of Robert Shipley’s vision for enhancing GIA’s reach and impact was a professional journal. G&G was established in January 1934 as a repository of gemological research for both gemologists and the retail jewel industry. From 1934 to 1980, G&G operated under the guidance of two editors-in-chiefs: Robert Shipley and Richard Liddicoat. Over the decades, the journal kept the same look and format it had at its inception. The publication was 5.5 x 8.5 inches, printed primarily in black and white with few photos. G&G published groundbreaking research and content, but with a modest appearance and limited readership, the journal needed an overhaul to get the attention of the gemological community at large.

In 1980, in anticipation of the Institute’s 50th anniversary, Liddicoat picked Alice Keller, an editor with a decade of experience in professional journals, to assume the position of managing editor and to overhaul GIA’s flagship publication. Under Keller’s leadership, G&G changed to an 8.5 x 11 inch, full-color publication. She established the peer-review system and cultivated an editorial review board that included some of the world’s most prominent gemologists and researchers.

Her efforts culminated in widely read, award-winning articles, and greater attention to gemology as a science. G&G itself won 34 awards under Keller’s leadership. She also oversaw the publication of the three-edition Gems & Gemology in Review series, which reprinted decades of articles on synthetic, treated, and colored diamonds, respectively, in book form.

After 22 years of service, she became editor-in-chief of G&G in 2002, continuing to move the journal into the electronic age with the same level of excellence and attention to detail she devoted to the print version. In addition to her editorial duties, she co-chaired GIA’s International Gemological Symposiums in 1999, 2006 and 2011. She was called the “stalwart guardian of G&G” by GIA’s then-CEO in 2010.

One of the Institute’s Staff of the Year recipients in 1991, Keller earned many accolades outside of GIA for her work, including an Excellence in Publishing award from the Women’s Jewelry Association and an Honorary Lifetime Membership from the American Gem Trade Association, both in 1998. She received GIA’s highest honor, the Richard T. Liddicoat Award for Distinguished Service, in 2003. She retired in 2011 but remains G&G’s editor-in-chief emeritus.

Beatrice Shipley, Eunice Miles and Alice Keller epitomized the ideals set forth by GIA, but they are by no means unique in the Institute. These three women changed the course of GIA, extending its global reach and setting the stage for the thousands of other women—and men—who have come through its doors as both employees and students. In the manner of Shipley, Miles, and Keller, the people of GIA continue to change the face of gemology, in 14 countries around the world, well into the 21st century. @topic:6


Publish Year: - Title: Robert Kammerling (1947–1996) Abstract: You’ve probably heard of Rambo, the film character known for rugged survival tactics. GIA boasts the legacy of “Kambo,” the nickname earned by brilliant, driven instructor and researcher Robert C. Kammerling. His intensity, intellect, and dedication inspired the loyalty of students and colleagues alike. In 1996, after Kammerling’s untimely death at age 48, GIA president Bill Boyajian lauded him as a “hero of modern gemology.”

Kammerling’s reputation as a giant among gemologists is well deserved. After an exotic early career traveling to Tibet, Ethiopia, and Afghanistan with the U.S. Civil Service, Kammerling followed his passion for gems and enrolled at GIA in 1981. He aced his graduate gemology exam with the highest score his instructor had ever seen. Six months after passing with flying colors, Kammerling was a GIA instructor himself, teaching courses in gem identification and colored stones and fielding questions from students with his characteristic barbed wit and keen insight.

It wasn’t long before the tireless instructor turned writer. He began by updating
GIA’s Gem Identification Manual and ultimately coauthored (with Cornelius Hurlbut) the 1991 second edition of Gemology, a pivotal textbook in the field.  In the 1980s and ’90s, Kammerling wrote hundreds of groundbreaking articles based on his research in far-flung gem locales. To the end, he remained convinced that true scientific understanding stems from firsthand experience.

As an individual, Kammerling was charismatic. As a gemologist, he applied that adventurous spirit and restless energy to practical breakthroughs in gem identification that benefited the industry. In the late 1980s, Kammerling and GIA colleague John Koivula investigated ways to identify diamond fractures filled with glass, a clarity enhancement technique that was wreaking havoc in the near-colorless diamond market. The duo discovered a practical visual clue, known as the “flash effect,” that became the identification standard. Joined by fellow researchers, Kammerling then went on an extensive U.S. tour to publicize the treatment and its detection.

Always a workaholic, Kammerling took his job home with him in the 1990s when leading the first major study of the emerald filler Opticon. Hunkered over mounds of emeralds on his kitchen table, he cleaned and treated them himself until the small hours of the morning. The consummate researcher’s persistence helped resolve a critical trade issue that had weakened demand for emeralds. In 2000, Kammerling’s contributions culminated in a new GIA emerald report gauging the degree of clarity enhancement in natural emeralds.

In 1995, Robert Kammerling received GIA’s Richard T. Liddicoat Distinguished Achievement Award. His far-reaching impact as an instructor, author, and researcher changed the industry for the better. @topic:8


Publish Year: - Title: D. Vincent Manson (1936–1999) Abstract: Gemologist and geologist Dr. Vincent Manson described himself as a dreamer, but he had the initiative to make his visions into reality. Born, raised, and educated in South Africa, Manson worked as a research assistant in the De Beers Diamond Research Laboratory in Johannesburg before earning his PhD in geology from Columbia University in 1969. His work as the curator of gems and minerals at the American Museum of Natural History in New York City led to several meetings with key GIA staff, including Richard Liddicoat, Eunice Miles, and Robert Crowningshield. Impressed by Manson’s abilities and respect for the Institute’s mission, Liddicoat offered him a position in Santa Monica.

Manson joined GIA as the director of research in 1976, setting up a new facility to generate original research and expand gemological knowledge. He remained with GIA until his death in 1999, becoming director of education in 1985 and ending his career as director of strategic planning. In this capacity, he was instrumental in moving GIA’s headquarters and home campus to its current location in Carlsbad, California.

During Manson’s tenure, GIA’s research facility used state-of-the-art analytical equipment and created a database where natural, treated, and synthetic gems could be documented and referenced. He continued to publish groundbreaking work on diamonds and colored stones and served as associate editor of Gems & Gemology for 19 years (1980–1999). He also served as a consultant to filmmakers who produced documentaries on geological formation. Building on his experience as a curator, he cultivated relationships with museums with notable gem collections. One such connection resulted in the celebrated “Nature of Diamonds” exhibit at the San Diego Museum of Natural History in 1999. In one of his most enduring contributions to the gemological world, he helped establish the International Gemological Symposium, which he chaired in 1982, 1991, and 1999. These contributions led to his posthumous receipt of the Richard T. Liddicoat Lifetime Achievement Award in 1999. @topic:6


Publish Year: - Title: Sunstone Quality Factors Abstract: This 11-ct. bicolor sunstone is highly desirable for its color alone. An attractive display of aventurescence and a unique cut make it even more valuable. – Robert Weldon

Color
Most sunstones have yellow, orange, or brown bodycolor. Green is extremely rare. Small inclusions create a reddish or golden sheen on top of any bodycolor, while larger inclusions create attractive, glittery reflections. Sunstone inclusions can be hematite, copper, or some other mineral.

	The 2.40-ct. faceted bicolor gem displays an unusual green and yellow combination. Gem cutters seek ways to display unusual colors from rough like the 9.36-ct. specimen. – Robert Weldon

	These fine-quality gems display some of the sunstone colors found in the Plush, Oregon, mining area. – Jeff Scovil, courtesy Jeff Scovil
Oregon sunstone is a transparent feldspar with copper inclusions. It comes colorless as well as in a wide variety of colors, including pale yellow, pink with brilliant aventurescence, orange, red, green, and blue-green. The red version is often marketed as “spinel red,” and its vivid hue—if not its hardness—rivals spinel or even ruby.

	Deep red sunstone from the Ponderosa mine is marketed as spinel red. Although it’s not as hard as spinel or ruby, this sunstone type has a vivid scarlet hue that can be equally lovely. – Bart Curren
Some Oregon sunstones are either bicolored or tricolored, and a rare few display color change. Currently, the top deep green, deep red, and intensely bicolored sunstones are considered extra fine.

	Some sunstones are bicolored, which makes them ideal for free-style designer cuts
	(bottom). They might also be tricolored, like this lovely 32.80-ct. Oregon sunstone (top).
	The cut is a spectacular example of the sculptor’s artistry. – Tino Hammid (bottom); Maha
	Tannous, courtesy Dust Devil Mining Company, Beaver, Oregon (top)
Cut
Sunstone is available in a wide range of shapes and sizes, from exquisite fantasy cuts for designer jewelry to precise caliber cuts for manufacturers.

	This “Dreamscape” fantasy-cut sunstone was created by gem designer John Dyer. – Lydia Dyer, Gem courtesy of John Dyer & Co.

	Caliber-cut sunstones are available for mass-market production or custom jewelry designs. – Valerie Power, courtesy Desert Sun Mining & Gem Co., Inc.
Clarity
All Oregon sunstones have an extra sheen that’s caused by copper inclusions. The sheen is there even if the inclusions aren’t large enough to create actual aventurescence.

	A photomicrograph shows inclusions in a gem from Oregon’s Ponderosa Mine, magnified 12 times. – Shane F. McClure, courtesy Dr. E. J. Gübelin Collection

	These oligoclase sunstone cabochons display an attractive adventurescent sparkle. – Edward Gubelin, courtesy Dr. Edward J. Gübelin Collection
Carat Weight
Sunstone can be found in relatively large sizes, but most caliber-cut stones weigh one carat or less.

	The unusual size of this 146.07-ct. oligoclase sunstone dwarfs the sunstones, moonstones, and other gems in the background. – Terri Weimer, courtesy Blue Moon Enterprise @topic:2


Publish Year: 2017 Title: Growth Tube Cluster in Sapphire Abstract: Surface-reaching growth tubes within a sapphire exhibit unaltered yellowish staining, an indication that the stone has probably not been heated. Combined with other observations, this suggests a possible Madagascar origin. Photomicrograph by E. Billie Hughes; horizontal field of view 1.4 mm.

Growth tubes are a typical inclusion in corundum and often seen during examination in the laboratory. While commonplace, a stunning cluster such as the one seen above calls out to the photomicrographer. At the surface these tubes are cut through and some black debris has become lodged inside the ends, while deeper within the stone they still display a fiery glow, reminiscent of rockets launching into the sky.

Not only do these tubes spark the imagination, but they can actually tell us a lot about the identity of their sapphire host. The limonitic staining found deeper in the tubes is a yellowish orange, suggesting that they have not been altered by heat treatment. These stains often turn a darker reddish or brownish color in heat-treated stones (J.I. Koivula, “Useful visual clue indicating corundum heat treatment,” Fall 2013 G&G, pp. 160–161).

Furthermore, we have observed in the past several months that these prominent growth tubes are a common feature in Madagascar sapphire. While the tubes can be found in corundum from other origins, they seem particularly common in the Madagascar material that has been entering the Bangkok market in greater numbers recently. When taken into account along with other features, they provide a clue to the origin of these sapphires. Thus, what initially appeared to be a mundane inclusion is both visually impressive and gemologically significant, as it provides hints to the origins and treatments of corundum. @topic:3


Publish Year: 2016 Title: Etch Marks, Negative Crystals, and Etch Tubes in Spinel from Madagascar Abstract: Figure 1. The multitude of negative crystals and growth tubes in the 2.18 ct spinel pebble are exposed under fiber-optic light. Photo by Victoria Raynaud; field of view 13.11 mm.

	During a recent study of blue sapphires from the Ilakaka region in Madagascar, the authors discovered a stone with an unusual appearance. Mixed in a parcel of blue sapphires purchased from Malagasy sapphire miner Nirina Rakotosaona was a 2.18 ct blue pebble (figure 1). RI (1.718) and SG (3.62) measurements identified it as a spinel. Mr. Rakotosaona had mined these stones near Antsoa village, along the Taheza River. Magnification revealed numerous triangular etch marks on the surface, which is not uncommon for spinel (Summer 2004 Lab Notes, p. 168). The frosted surface of the stone made it difficult to study its internal features, so we polished a window in order to observe them.

	What we found was a spectacular internal world, with several well-developed negative crystals associated with etch tubes (figure 2). These etch features were characterized by a narrowing of the tubes toward the center of the crystal, indicating that they were produced by dissolution of spinel after the crystal had formed. This preferential dissolution was located at weaker structural zones in the spinel, which might be related to the presence of the negative crystals.

Figure 2. Negative crystals with stubby etching and very long etch tubes within the spinel. The triangular etch marks are visible in the background. The image was taken using a combination of brightfield and fiber-optic lighting. Photomicrograph by Victoria Raynaud; field of view 2.67 mm.

	While all the negative crystals were aligned and had the overall classic octahedral form for spinel, they also showed modifications such as twinning and short stubby etching (figure 3). The etch tubes radiated outward from these negative inclusions or passed through them. Etch tubes are well known in sapphires from Madagascar, but this stone shows they can also be found in blue spinels from the island. It was this etching that made for one of the most interesting inclusion scenes the authors have encountered.

Figure 3. Octagonal negative crystals associated with slender etch tubes, seen under a fiber-optic light. Photomicrograph by Victoria Raynaud; field of view 1.44 mm. @topic:3


Publish Year: 2022 Title: An A-maze-ing Fingerprint in Spinel Abstract: A web-like fingerprint creates a maze-like pattern in this spinel from Vietnam, observed with darkfield and diffuse fiber-optic illumination. Photomicrograph by E. Billie Hughes; field of view 5 mm. Courtesy of Vitalit Gems.
Of the variety of inclusions that can be seen in spinel, perhaps the most familiar are angular octahedral crystals. In many cases, we even see these crystals arranged in neat rows, forming delicate “fingerprint” inclusions.
However, spinel fingerprints can also take on other appearances, as observed in a Vietnamese sample that recently passed through our laboratory (see above). This stone contained a partially healed fissure with a maze-like pattern that was evident when lit with darkfield illumination. With the addition of diffuse fiber-optic illumination, small angular areas of the channels seemed to light up with a highly reflective appearance. Myriad inclusion scenes make spinel a fascinating gem to observe. @topic:3


Publish Year: - Title: Unveiling the Cat’s-Eye Effect in a 75 ct Colombian Emerald Pair Abstract: When Colombian emerald cutter Misael Angel Rodriguez was offered a large chunk of broken trapiche emerald in September 2012, he very nearly passed on the bid. The rough portion weighed nearly 370 ct and was covered in a black carbonaceous coating, with only a glimpse of green to suggest that it even contained emerald. Several other conocedores, or experts, had already declined to buy it, which added to Rodriguez’s concerns. Placing a bid on it was an expensive gamble: The piece was large and presumably mined at Muzo, Colombia’s historic emerald source. “But what secret does it hold?” Rodriguez wondered.

	Once cleaned, this large trapiche emerald portion from Muzo weighed more than 300 ct. The rough revealed two major sections that might be suitable for cutting. All photos courtesy of Misael Angel Rodriguez.
Emerald Mystery Revealed in Cutting
Emerald dealers are accustomed to speculation, because large pieces are inherently unknowable. Rodriguez’s dilemma was comparable to that of jadeite dealers in Myanmar (Burma), who often face similar anxieties when purchasing jadeite boulders. They are in effect betting on finding a valuable, deep color inside the stone—but not really knowing until they cut a window, or slice the boulder. For the sellers of such pieces there is also a gamble. More often than not, they too decline to cut windows into the rough for fear of losing weight, or perhaps cutting away the one valuable piece in an otherwise insignificant stone.

Rodriguez and wife Claudia Beltran Rubiano, both experienced emerald cutters, ultimately decided to take the gamble and purchase the rough. They cut one corner, and then another, attempting to judge the potential gem’s depth. They soon discovered that the chunk actually contained two portions of a six-ray trapiche emerald and concluded that two stones of similar size might be fashioned from it. They also noted a fine tube-like internal structure at one side of the rough, which is characteristic of the type of material that produces cat’s-eyes. As they further polished off the skin, they began to witness the unmistakable green of fine emerald.

“That is the riddle of emeralds in the rough,” Rodriguez explained. “Their splendor is often concealed.”

	Next, Rodriguez trimmed excess pieces and sawed through the rough.
He and his wife started to slowly remove the carbonaceous outer layer of the emerald, while removing small holes and pits in the material. Bearing in mind that trapiche emeralds often yield cat’s eyes, and having noticed the fine tubes that give rise to the phenomenon, they placed small, curved facets into the rough, hoping to coax out a cat’s-eye effect. They soon found the eye’s strongest orientation, which gave them further guidance on how both gems would have to be cut.

Both of the long cabochons began to take shape: Rodriguez, with his greater cutting experience, began fashioning what they considered the finer one. “But after each day of cutting and polishing, Claudia’s always looked better and finer than mine,” Rodriguez recalled.

	Two emeralds were then pre-formed to achieve a nearly matched weight and color.
Once polished, the pair of emeralds weighed 105 carats total, which Rodriguez believes was a record weight for a matched pair. But sacrifices in weight still had to be made because of the inclusions, bringing the pair down to about 75 carats total. Rodriguez noted that gems of such size and quality, in a matched pair, had never been seen to date in Colombia.

Shortly after the February 2013 Tucson gem show, GIA asked to see the stones, and they were sent to the Carlsbad laboratory for further examination.

	Two large matching cat’s-eye emeralds, ultimately weighing close to 75 carats total, emerged from the rough trapiche. Photo by Robert Weldon, GIA.
GIA Laboratory Examination
Both stones were received at GIA in the spring of 2013. Their gemological properties were typical of cat’s-eye emeralds examined in the past. We recorded a spot RI of 1.57, chrome lines in the red portion of the spectrum, and no reaction to ultraviolet light.

What was really interesting about them was the internal structure that gave rise to the cat’s-eye effect. The dense parallel growth tubes appeared somewhat transparent, quite unlike the needles or growth tubes that cause the chatoyancy in many other cat’s-eye specimens. As noted, this type of structure in emerald is often found in the individual pie-shaped sections of trapiche emeralds. However, only rarely is it dense enough to cut a strong cat’s-eye, as was the case for the large matched pair we saw.

In his 1981 book Emeralds and Other Beryls, noted beryl connoisseur John Sinkankas wrote that cat’s-eye emeralds are so rare as to be practically nonexistent in the market. Since the book’s publication three decades ago, several Colombian cat’s-eye emeralds have been reported, and they are slightly more prevalent on the international market today. This is partly because emerald cutters are now looking at rough material with an understanding of when rare cat’s-eye emerald might be revealed, and also because collectors are actively seeking out these stones for their rarity and beauty. @topic:3


Publish Year: 2019 Title: Rubies from Rock Creek, Montana Abstract: Figure 1. A suite of nine rubies from the Rock Creek sapphire deposit in Montana. The stones range in weight from 0.172 to 0.578 ct. Photo by Kevin Schumacher, courtesy of Jeffrey R. Hapeman, Earth’s Treasury.

North America has several productive colored stone deposits, from gem tourmaline in Maine and California, to emerald in North Carolina, to peridot, turquoise, and opal in the Western states. One gap in all of this gemological wealth is the virtual lack of any American ruby sources, with the exception of a minor deposit in North Carolina (G.F. Kunz, Gems & Precious Stones of North America, Dover Publishing, Mineola, New York, 1968, 367 pp.). This is surprising given the number of geographic locales in the American West named after the red variety of corundum (i.e., the Ruby Mountains of Nevada and the “Ruby Peaks” found in several states). In his epic tome Yogo: The Great American Sapphire (1987), Stephen M. Voynick provides an explanation for this apparent geographic contradiction. He proposes that early prospectors named these sites after stumbling upon garnets and mistaking them for rubies. Their vision also may have been clouded by dreams of wealth and hopes of striking a rich gem deposit. But what if there is some shred of truth to the old prospectors’ tales?
This journal recently described a ruby submitted to GIA with gemological properties that clearly indicated a Montana origin (Winter 2018 Lab Notes, pp. 434–435). Additionally, Palke et al. (2018) noted the occurrence of rare rubies and violet sapphires from Yogo Gulch (“A common origin for Thai/Cambodian rubies and blue and violet sapphires from Yogo Gulch, Montana, USA?” American Mineralogist, Vol. 103, No. 3, 2018, pp. 469–479). Over the course of several years, Jeffrey R. Hapeman (Earth’s Treasury, Westtown, Pennsylvania) has amassed a unique collection of true rubies from Potentate Mining’s operation at Montana’s Rock Creek deposit. According to Hapeman and Potentate’s Warren Boyd, rubies were only recovered when the miners were asked to put aside anything that resembled a garnet so they could be examined more carefully. Presumably, many rubies had been discarded as garnets in years past. Regardless, rubies from this deposit are extremely rare. To date, only 29 rubies—just over 6 grams—have been found in more than 400 kilograms of mine production.
Nine faceted Montana rubies from 0.172 to 0.578 ct (figure 1) and seven rough rubies from 0.11 to 0.34 grams, supplied by Mr. Hapeman, were included in this study. Additionally, 10 pink, blue, and green sapphires from Hapeman and 15 from GIA’s reference collection, gathered on-site at the Potentate mine, were used for comparison with the rubies. Standard gemological testing of several of the rubies with a handheld spectroscope yielded chromium spectra. The stones displayed weak to moderate red fluorescence in long-wave UV and no fluorescence under short-wave UV. Microscopic examination showed inclusion scenes resembling those of typical Montana sapphires, including crystalline or glassy melt inclusions surrounded by decrepitation halos (figure 2, left). Also common were angular particulate bands, often arranged in partial hexagonal patterns following the crystallographic orientation of the host corundum (figure 2, center). These bands are composed of loosely to densely spaced particles, short to long needles, and/or reflective platelets (figure 2, right). These features are consistent with material from the secondary Montana sapphire deposits at Rock Creek and the Missouri River. Similar inclusion scenes were also observed in the blue, green, pink, and purple sapphires from this study (figure 3).

Figure 2. Inclusion scenes in Montana rubies. Left: A decrepitation halo surrounding an inclusion. Field of view 2.23 mm. Center: Angular bands composed of loosely to densely packed particles and short to long needles. Field of view 3.57 mm. Right: Oriented needles and platelets. Field of view 1.26 mm. Photomicrographs by Aaron Palke (left and right) and Tyler Smith (center).

Figure 3. Left: An inclusion with a partially healed decrepitation halo surrounded by angular particulate bands in a pink Montana sapphire. Right: A typical inclusion scene in a blue Montana sapphire composed of partial hexagonal particulate bands, loosely packed short to long needles, and reflective platelets. Photomicrographs by Aaron Palke; fields of view 2.34 mm (left) and 4.08 mm (right).
The rubies were analyzed by laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) to uncover their trace element patterns for comparison with the blue, green, pink, and purple sapphires from Montana also studied here. Generally, the rubies had trace element profiles of 13–38 ppma Mg, 16–81 ppma Ti, 1–27 ppma V, 408–2400 ppma Cr, 1106–2958 ppma Fe, and 11–20 ppma Ga with averages of 24 ppma Mg, 31 ppma Ti, 8 ppma V, 979 ppma Cr, 2123 ppma Fe, and 15 ppma Ga. Except for Cr, these values are consistent with the general ranges of pink/purple and blue/green Montana sapphires shown in the supplementary table 1. This is seen more easily in a Cr vs. Ga plot, which exhibits a continuous and seamless transition in Cr values increasing from the blue/green sapphires through the pink/purple sapphires to the true red rubies (figure 4). Additionally, plots not involving Cr tend to show similarities in the trace element chemistry of all other elements between Montana rubies and pink/purple and blue/green Montana sapphires. Figure 5 shows this similarity; it also compares these data against sapphires from a select number of globally important sapphire deposits. Figure 5 suggests that, except for Cr, the trace element profiles of Montana rubies and sapphires are the same, especially in comparison to other global sources of gem corundum. The rubies and pink/purple sapphires have a slight tendency toward lower Mg values, although it is unclear if this is statistically valid or a result of the small sample size. The trace element Cr appears to operate independently of most of the other trace elements and can vary more than four orders of magnitude, which is unheard of for the other trace elements in Montana sapphires. While further research may elucidate these geochemical mysteries, these unusual stones are a testament to the unique corundum produced at Rock Creek.

Figure 4. A Cr vs. Ga plot for blue/green sapphires, pink/purple sapphires, and rubies from the secondary Montana sapphire deposits (Rock Creek and Missouri River).

Figure 5. A Mg vs. Fe plot for sapphires and rubies compares material from Rock Creek and Missouri River with a small sampling of data from other important sapphire localities. @topic:2


Publish Year: 2015 Title: Stars Are Out in Paraíba Tourmaline Abstract: Figure 1. Under point-source light, these 1.06 and 0.90 ct Paraíba tourmaline cabochons purchased in Brazil in the early 1990s display four-ray stars. Photo by Robert Weldon.

	The rarity of Brazilian Paraíba tourmaline, with its vibrant, almost unearthly colors, makes it a coveted gem the world over. What a delight to discover a pair of stars shining out from among many non-phenomenal stones in a parcel. This was a fruitful result of gemologist Elaine Rhorbach’s regular use of a point-source light for examination of all materials she encounters in the marketplace. Wherever she is in the world, this former nurse carries her powerful otoscope—no longer examining ears, but rather checking for any optical phenomena in gems, even where none is expected.

	The phenomenon of asterism is seen in a variety of gem materials fashioned as cabochons. The multiple chatoyant bands of light forming these stars are caused by the scattering of planar light by sets of parallel structures. These are often inclusions such as minerals, voids, and structural defects, but they may also be manifested by natural surface features of the crystal left intact on the gem’s base (e.g., tourmaline prism face striations) or etched into the surface by hand. The crystal structure of the host dictates the number of bands, and with mineral inclusions in particular, the orientations are a result of complex chemical interactions between the inclusions and their host. Orientation of the cut gem also determines what effect is seen. For instance, multi-star quartz is a member of the same trigonal crystal class as tourmaline; it displays four- and six-ray stars, depending on viewing orientation in relation to its crystallographic axes of symmetry.

	In the case of the 1.06 and 0.90 ct Paraíba tourmaline cabochons seen in figure 1, the c-axis of the larger gem is along its length and that of the smaller specimen is across its width. Thus, the view from above is perpendicular to the crystal’s c-axis. Fluid-filled inclusions paralleling the c-axis dominate the gems’ microworld, causing a distinct chatoyant band perpendicular to the axis. A faint band seen crossing this appears to be caused by the slight widening of the fluid-filled inclusions (figure 2). Since the inclusions are roughly rectangular as they are aligned parallel to the c-axis of the crystal, they produce two directions of reflections oriented at 90°. The elongate direction has more reflective surface area and therefore produces a brighter chatoyant band, while the width has less surface area and produces a weaker chatoyant band from the same reflective inclusion set. While EDXRF detected the presence of copper in these vibrant gems, affirming their Paraíba nature, the subtle stars elevated them into the class of rarefied connoisseur gems—another example of the power of inclusions!

Figure 2. Reflective fluid-filled inclusions parallel to the c-axis of the Paraíba tourmaline scatter the light, forming the stronger chatoyant band. A faint band seems to be caused by a slight widening of these inclusions. Photomicrograph by Nathan Renfro; field of view 1.20 mm. @topic:3


Publish Year: 2018 Title: Universal Microscope Upgrade Kit Abstract: GemoAid’s new Universal Microscope Upgrade Kit converts a gemological microscope into a polariscope, while the colored filters and diffuser plate are useful in observing subtle color zoning features. Photo by Kevin Schumacher.

Israel-based GemoAid recently released the Universal Microscope Upgrade Kit (see above). Designed by gemologist Guy Borenstein, it offers a variety of accessories that maximize the use of a standard gemological microscope when observing unknown gems. The kit includes four mounting rings and two extension rods, which should be compatible with almost any microscope that has transmitted light capabilities. Also included are two polarizing filters, a blue filter, a yellow filter, a diffuser plate, and an immersion cell. The product, which retails for US$130, also includes a one-year warranty from the date of purchase.

The combination of components allows the microscope to act as a polariscope for making critical optical observations of gemstones and their inclusions. The colored filters and diffuser plate can also facilitate observation of subtle color zoning features such as curved color bands in yellow flame-fusion sapphires, which would be diagnostic of their manmade origin and difficult to resolve without a blue filter.

The unit examined by the author was found to be a little loose where the metal rod attaches to the mounting ring. The author also found the immersion cell to be too tall, making it difficult to manipulate small stones with tweezers—which is quite critical in immersion microscopy—but certainly the larger cell will accommodate larger stones and perhaps rough crystals.

Overall, the quality and price of the upgrade kit are well matched. It is of great value to the serious gemologist. @topic:8


Publish Year: 2018 Title: Emeralds Filled with Epoxy Resin: DiamondView Observations Abstract: Figure 1. This 16.15 ct emerald was filled with epoxy resin. Photo by Lai Tai-An Gem Lab.

Emeralds from all sources routinely contain surface-reaching fissures, and as a result are subjected to clarity enhancement processes (oiling or resin filling) to improve their appearance. The quantity and variety of emerald-filling substances undoubtedly affects the final market value (M.L. Johnson et al., “On the identification of various emerald filling substances,” Summer 1999 G&G, pp. 82–107). Recently, the Lai Tai-An Gem Lab received a stone—reported as an emerald by the client—for identification services, with a request to focus on the degree of clarity enhancement. DiamondView imaging allowed us to visually explain the degree of filling in a way the client was quickly able to understand.

Figure 2. When viewed through a gemological microscope, “blue flashes” characteristic of resin-filled emeralds are clearly visible. Photo by Lai Tai-An Gem Lab; field of view 8.8 mm.

Figure 3. Characteristic epoxy resin peaks were detected at 3061, 3040, 2965, 2930, and 2870 cm–1 with FTIR spectrometry.
The transparent emerald-cut stone weighed 16.15 ct and measured 16.80 × 14.07 × 9.48 mm. It exhibited a light to medium green saturation and contained white hazy inclusions that were visible to the eye (figure 1). Standard gemological testing revealed an RI of 1.570–1.575, an SG of approximately 2.66, and a weak yellowish green reaction under long-wave ultraviolet radiation. Magnification with a gemological microscope revealed fluid and three-phase inclusions typical of natural emeralds. When turning the specimen, “blue flashes” characteristic of resin-filled material were seen within many of the fissures (figure 2). These results confirmed that the stone was a natural, clarity-enhanced emerald. Infrared spectrometry was subsequently performed to analyze the filling in more detail. Epoxy resin peaks at 3061, 3040, 2965, 2930, and 2870 cm–1 (figure 3) confirmed the epoxy resin treatment of the stone, as indicated by the initial microscopy.
Although it may not be difficult for experienced gemologists to identify various emerald-filling substances using high-end equipment like Fourier-transform infrared (FTIR) or Raman spectroscopy, we wanted to check on the suitability of another tool to assist in identifying fillers and to help see the extent and degree of filling applied. We turned to the DiamondView and obtained some interesting images for this clarity-enhanced emerald.

Figure 4. Surface-reaching fissures with greater concentrations reveal a stronger blue reaction when observed in different directions under the DiamondView’s visible light (left) and when exposed to the unit’s ultra-short-wave UV energy (right).
The stone’s surface was first observed in different directions under the DiamondView’s visible light source until obvious surface-reaching fissures appeared. Subsequent exposure to the unit’s ultra-short energy UV light clearly revealed the epoxy resin filler within the fissures as a series of blue lines extending over the entire surface against the beryl’s orange-fluorescing bodycolor. The more severe (quantity in relation to width and depth) the treated fissures were, the stronger the blue reaction (figure 4). The results of this simple test show how the DiamondView may be applied. Although the DiamondView cannot precisely identify the fillers, it does provide a means of detection that can be applied to a variety of gems. The option of ultra-short-wave radiation should be considered, as there may be concerns about the color and structural durability of host and fillers that have not been fully taken into account. @topic:3


Publish Year: 2023 Title: Gemmes Abstract: The new French-language digital publication Gemmes, published by Gemmologie & Francophonie.
Swiss-based Gemmologie & Francophonie has launched a French-language digital publication, Gemmes (see above). Released twice a year, the magazine covers a range of gem and jewelry topics and is open to submissions. Each article has an English-language abstract and figure captions. The debut issue can be downloaded at gemmologie-francophonie.com/index.php/la-revue-gemmes. The second issue, available in September, will examine lab gemology, art history, ethics, and more. @topic:6


Publish Year: 2014 Title: Record-Size Natural Moissanite Crystals Discovered in Israel Abstract: Figure 1. The largest known natural moissanite crystal, found along the Kishon River in northeastern Israel, measures 4.1 mm in its longest dimension. Photo by Vered Toledo.

Synthetic silicon carbide (SiC) is well known in the gem and jewelry market as synthetic moissanite. Natural SiC is very rare and has been found as tiny crystals (usually less than 1.5 mm) in only a few deposits worldwide (Y. Bauer et al., “Moissanite from middle mountains of Czechoslovakia,” International Geology Review, Vol. 7, No. 7, 1965, pp. 1194–1206; A.A. Shiryaevet et al., “Moissanite (SiC) from kimberlites: Polytypes, trace elements, inclusions and speculations on origin,” Lithos, Vol. 122, No. 3–4, 2011, pp. 152–164, and references therein).
Over the past 14 years, however, more than 2,500 crystals of natural moissanite have been discovered by Shefa Yamim, an Israeli exploration and mining company. The crystals come from primary and alluvial deposits along the Kishon River, near Haifa in northern Israel. Shefa Yamim began prospecting in this area following the 1988 prophetic statement of the Lubavitcher Rebbe that “precious stones and gems” would be discovered in the valley next to Haifa (see video at http://youtu.be/_uzY5mV8rdY). In 2000, the company unearthed moissanite crystals ranging from 0.1 to 1 mm in size; two years later, 2.2 mm crystals were found. In 2009, a 3.5 mm moissanite discovery set a world record, only to be surpassed in August 2012 by a crystal measuring 4.1 mm—the largest specimen to date (figure 1 and http://goo.gl/JZFiwe).
There is evidence of even larger crystals, as many broken crystals were discovered. Some crystals have also been found in situ in the volcanic rock of the Rakefet magmatic complex, one of the magmatic bodies of Mount Carmel, just southeast of Haifa, which is drained by a small tributary to the Kishon River.
We studied 30 Israeli crystals ranging from less than 1 mm to 3.5 mm. All were identified as moissanite (SiC 6H) by Raman spectroscopy. Their morphology was hexagonal, bipyramidal to platy, with the pinacoid generally present (figures 2 and 3). The crystals were often broken, particularly the larger ones with rounded, shiny surfaces (again, see figure 1). As shown in figure 3, the crystals were transparent and ranged from deep blue (the most common color) to light green. Except for size, these characteristics are similar to those of other natural moissanites documented in the literature. The crystals are often associated with small bits of creamy white or red complex matrix.

Figure 2. These natural moissanite crystals are hexagonal to pyramidal, showing rounded areas that may result from either growth or dissolution. The crystals range up to 2.5 mm (not to scale). Composite photo by Aurélien Delaunay.

Figure 3. The colors seen in moissanite from the Mount Carmel area of northern Israel range from dark blue to light green. Note the broken or rounded morphology. Composite photo by Aurélien Delaunay.
The crystals we examined were inert under long- and short-wave UV radiation, with the exception of five small green to light green samples. In these five specimens, medium to strong orange luminescence was seen under either long- or short-wave UV. These were found to be magnetic when placed next to a powerful permanent alnico magnet. All of the samples contained small metallic inclusions, the largest approximately 30 microns in size, which could be the source of magnetism. We will continue to follow moissanite exploration in this area, and a more in-depth research paper is forthcoming. @topic:4


Publish Year: 2017 Title: Sapphires with Unusual Radial “Eye” Structure Abstract: Figure 1. This 6.38 ct sapphire from Luc Yen, Vietnam, shows a unique radiating aggregate habit. Photo by Robison McMurtry, courtesy of Lucas Fassari.

The Luc Yen district in northern Vietnam produces some remarkable stone varieties, including ruby and red and cobalt-blue spinel. Recently, Geir Atle Gussiås of BalderGems in Luc Yen procured some interesting sapphires from local gem traders. These stones exhibited a radial pattern often accompanied by concentric color zoning. This pattern is commonly seen in minerals that precipitate from fluids such as carbonates and cryptocrystalline silica varieties, but to our knowledge it has never been observed in corundum. All of Gussiås’s samples were opaque and cut as cabochons to display this strange growth pattern. Due to their distinctive appearance, these gems have been called “eye sapphires” in the trade (see figure 1).

The patterns exhibited different forms and sizes but were always a combination of blue and white, with a lower polish quality in the white areas. Raman spectroscopy confirmed that both the white and blue areas were corundum, but the presence of diaspore was detected only in the whiter areas. Some areas also showed a mottled texture and small unidentified black inclusions (figure 2). Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) analysis of the sapphire in figure 1 revealed a low iron content, which excludes a basalt-related origin. Epigenetic yellow goethite was found in several fractures on the top of the cabochon. The presence of this mineral was evidence that the stone had not been heat treated (figure 3): Goethite, an iron hydroxide mineral, alters to rust-colored hematite at relatively low temperatures (J.I. Koivula, “Useful visual clue indicating corundum heat treatment,” Fall 2013 G&G, pp. 160–161). Corundum heat treatments have been performed for centuries and are widely accepted in the trade, but this stone needed no extra enhancement beyond cutting and polishing to reveal its anomalous beauty.

Figure 2. This area of the sapphire has a mottled blue and white appearance and hosts unidentified black inclusions. Photomicrograph by Victoria Raynaud; field of view 4.80 mm.

Figure 3. This fracture with epigenetic yellow goethite staining indicates that the sapphire has not been subjected to heat treatment. Photomicrograph by Hollie McBride; field of view 4.79 mm.
While the cause of this unusual radial aggregate structure remains unknown, it is certainly a welcome novelty in the collector gem market. @topic:3


Publish Year: 2020 Title: Black Star Sapphire with Dual Treatments Abstract: Figure 1. The 75 ct black star sapphire that was brought in for testing. Photo by Wimon Manorotkul.

Black star sapphires primarily come from Kenya, Australia, and Thailand. Unlike other star sapphires and rubies, the asterism in these stones generally results from the exsolution of ilmenite (FeTiO3) and/or hematite (α-Fe2O3) instead of rutile (TiO2). Rutile and ilmenite/hematite exsolve in different directions: rutile along the second-order hexagonal prism {112̅0} and ilmenite along the first-order hexagonal prism {101̅0}. If both are present in the same stone, a 12-ray star results. The ilmenite/hematite crystals are far more “platy,” and thus their layers tend to form planes of weakness. Breakage along those planes is termed parting. Parting differs from cleavage in that it results from structural planes of weakness due to imperfect growth rather than inherent weakness. There are often two different parting planes in the stones. One corresponds to the exsolution of ilmenite/hematite in the plane of the basal pinacoid {0001}. The other corresponds to planes of exsolved boehmite/diaspore along the rhombohedron {101̅1}.
In Thailand, one often sees cavities on the back of black star sapphires filled in with brown dopping varnish. It is only the basal parting that comes into play with black star sapphires, because the exsolved hematite that causes the lack of adhesion is only in the basal plane. It is because of this parting that the stones get filled with dopping varnish, to conceal large holes in the base. Note that the type of dopping varnish is of a color that matches the stone.

Figure 2. Left: Two large pits on the base of the star sapphire contain brown dopping varnish (the white areas are adhesive from tape). Field of view 30 mm. Right: Under long-wave ultraviolet light (365 nm), the dopping shellac fluoresced bright orange. Field of view 27 mm. Photomicrographs by Richard W. Hughes.
In May 2020, a client submitted a large 75 ct black star sapphire for testing (figure 1). The base of the stone contained two large pits filled with brown dopping shellac (figure 12, left). Interestingly enough, the shellac fluoresced bright orange under long-wave ultraviolet light (365 nm) (figure 2, right). Following the client’s approval, we removed the shellac with alcohol and noticed a curved area exhibiting an unusual flow-like structure that looked suspiciously like glass. Unfortunately, attempting to get a Raman spectrum on the area was unsuccessful.

Figure 3. A close-up view of the shellac in the lower pit revealed trapped gas bubbles and black debris. Photomicrograph by Richard W. Hughes; field of view 5 mm.
Careful microscopic examination showed what looked like gas bubbles trapped between the glassy material and the sapphire below (figure 3). Scratching the surface of the cavity with a number 7 hardness point confirmed that the area could not be corundum. Immersing the gem in methylene iodide showed the glassy area to cover roughly two-thirds of the base of the cabochon (figure 4). Energy-dispersive x-ray fluorescence (EDXRF) testing on the area suspected to be glass revealed a lead (Pb) component of over 3%.

Figure 4. Immersion in methylene diiodomethane (n = 1.741) reveals the extent of the glass filling on the base of the cabochon (the dark area that spreads across a large portion of the base). Photomicrograph by Richard W. Hughes; field of view 30 mm.
A variety of tests were brought to bear on this specimen, from the simple (hardness) to the high-tech (EDXRF). The results of these tests revealed a gem that had been treated by filling with two different substances: glass and dopping varnish. @topic:3


Publish Year: 2002 Title: “Diffusion Ruby” Proves to be Synthetic Ruby Overgrowth on Natural Corundum Abstract: A relatively new production of red corundum, reportedly from Bangkok, has been offered for sale in recent years. Although the producers claimed that these stones were red diffusion-treated corundum (i.e., a shallow coloration induced by the lattice diffusion of chromium), the surface layer is actually a synthetic ruby overgrowth on natural colorless to near-colorless corundum. The overgrowth layer, after re-cutting, typically ranged from 0.1 to 0.3 mm thick. This material can be distinguished from red lattice diffusion–treated corundum by the presence of a boundary plane and two different types of inclusion features: those that occur in the natural corundum core and those present only in the synthetic overgrowth. This product demonstrates that as treatment techniques continue to evolve, the distinction between natural, treated, and synthetic corundum may become increasingly difficult to define. @topic:3


Publish Year: 1995 Title: The Yogo Sapphire Deposit Abstract: Yogo Gulch, discovered more than 100 years ago, is one of four major sapphire-producing areas in Montana, United States. Yogo sapphires are known for their uniform, well-saturated blue color; relative absence of inclusions and zonation and high luster and brilliance in both artificial and natural light; they do not require heat treatment. Rough crystals, usually flat with low cutting retention, generally weigh less than one carat (but have been reported up to 19 ct). Unlike the other Montana deposits, which are secondary, Yogo sapphires are mined directly from a lamprophyre host rock. There are at least six known dikes, five sapphire-bearing, at Yogo. From 1895 to 1994, the Yogo deposit produced an estimated 18.2 million carats of rough that are believed to have yielded more than 500,000 carats of cut stones. Considerable reserves remain. @topic:2


Publish Year: 2000 Title: Purple to Purplish Red Chromium-Bearing Taaffeites Abstract: Gemological, microscopic, chemical, and spectroscopic properties are given for eight purple to purplish red chromium (Cr)- and iron (Fe)-bearing taaffeites and, for comparison, two grayish violet Fe-bearing but Cr-free samples. The eight purple to purplish red stones represent the largest sample of this extremely rare (i.e., Cr-bearing) variety of taaffeite that has been included in a single study; these taaffeites contain up to 0.33 wt.% Cr2O3, 2.59 wt.% FeO, and 2.24 wt.% ZnO. The purple to purplish red color is a function of the relative amounts of Fe and Cr present. Apatite and zircon crystals are common inclusions in taaffeite. Also present were healed fractures that consisted of negative crystals with multiphase fillings that contain magnesite. @topic:1


Publish Year: 1993 Title: Heat Treating the Sapphires of Rock Creek, Montana Abstract: Renewed interest in large-scale commercial mining of Montana sapphires motivated a detailed study of the heat treatment of sapphire from the Rock Creek deposit. During the course of this systematic study, over 75,000 stones were processed. It was found that approximately 65%-70% of the pale blue, pale green and near-colorless sapphire could be converted to well-saturated blue and yellow colors. Some improvement in clarity was noted as well. Yellow hues were easily developed by heating in oxidizing atmospheres and were relatively insensitive to time and temperature. Blue hues were developed by processing in reducing atmospheres. The relatively high iron content of Rock Creek material restricts the range of reducing conditions that can be used to achieve optimal coloration because of hercynite precipitation in the sapphire. @topic:3


Publish Year: 1986 Title: The Coscuez Mine: A Major Source of Colombian Emeralds Abstract: The Muzo emerald district, in Boyacá, Colombia, contains several mines. Although the Muzo mine is undoubtedly the best known, the Coscuez mine is rapidly gaining significance as a major source of fine emeralds. Yet few in the trade outside of Colombia are aware of the importance of Coscuez or know about the emeralds mined there. The Coscuez mine is literally hundreds of years old, and its history is closely tied to that of Muzo. Located only about 10 km apart, the two areas also share many geologic features and both are currently exploited using open-cut mining methods. The Coscuez emeralds are similar to Muzo stones in their physical properties, but they occur in a somewhat broader range of hue and saturation. Prospects for even greater production at Coscuez in the future are good. @topic:9


Publish Year: 1991 Title: Treated Andamooka Matrix Opal Abstract: Matrix opal from Andamooka, in South Australia, is a precious opal-included porous rock that is commonly color enhanced (carbon impregnated) to imitate the highly prized black opal from Lightning Ridge in northern New South Wales, Australia. This material has been commercially available since the mid-1950s and is often referred to as “sugar treated." A basic sugar acid-carbonizing technique is used to carbonize, and thus darken, the cream-colored matrix of prepolished stones so that the play-of-color is more prominent. The carbon impregnator in treated Andamooka matrix opal can be readily identified with low-power magnification. @topic:13


Publish Year: 2013 Title: Phosphorescence in Synthetic Sapphire Abstract: Figure 1. This 4.89 ct colorless synthetic sapphire was presented as a sapphire. Photo by Meenakshi Chauhan.

              A 4.89 ct colorless oval mixed-cut specimen was submitted as a sapphire to the Gem Testing Laboratory at the Indian Gemological Institute in Delhi for identification (figure 1). Standard gemological examination gave an RI of 1.760–1.768, with a uniaxial negative optic sign and a birefringence of 0.008, as well as a hydrostatic SG of 4.00. These properties were consistent with sapphire. While this specimen was eventually proven to be synthetic, its unusual characteristics—a lack of curved growth banding visible in the DTC DiamondView and very rare phosphorescence—called for instrumentation generally used in diamond identification.

	Figure 2. These fine, linear cracks near the girdle resemble long needles. Photomicrograph by Meenakshi Chauhan; magnified 40×.
Magnification showed what appeared to be long needles near the girdle, but closer examination revealed they were long cracks (figure 2). Rather than the Plato lines generally found in light-colored flame-fusion synthetic sapphires, the sample displayed two sharp planes under crossed polarizers. These planes, which had a noticeable separation in between, were visible in twinning lamellae position. Small stress knots near the table surface—but no physical inclusions—were also visible under crossed polarizers (figure 3). Such cracks, which are generally found on the surface of synthetic sapphire, may be due to stress during crystal growth.

	Figure 3. These small stress points, visible on the table between crossed polarizers, were confined to a small space. Photomicrograph by Meenakshi Chauhan; magnified 30×.
The sample was inert to long-wave UV radiation but showed a chalky blue fluorescence in short-wave UV, a common feature of synthetic sapphires. It also produced 30 seconds of phosphorescence—the first time this contributor has observed phosphorescence in sapphire, natural or synthetic. Examination in the DiamondView also showed an uncommon blue phosphorescence (figure 4), but it did not show curved growth banding—a fluorescence pattern normally seen in synthetic sapphire grown by the flame-fusion process.

	Figure 4. The colorless sample showed blue phosphorescence in the DiamondView, evidence of its synthetic origin. Image by Meenakshi Chauhan.
Identification could only be made on the basis of short-wave UV transmission analysis using the SSEF Diamond Spotter. When the instrument was switched on, short-wave UV radiation transmitted through the sample and the green dot glowed. The specimen’s transparency under the Diamond Spotter’s short-wave emission at 254 nm proved its synthetic origin, as natural sapphire does not transmit short-wave UV below 288 nm (S. Elen and E. Fritsch, “The separation of natural from synthetic colorless sapphire,” Spring 1999 G&G, pp. 30–41, http://dx.doi.org/10.5741/GEMS.35.1.30).

Despite the confirmation of synthetic origin, no conclusion could be made regarding the synthesis process used. Consistent with specimens grown by the Czochralski pulling method, there were no curved color bands, inclusions, or Plato lines. Conversely, the specimen’s chalky blue fluorescence and twinning are indicative of flame-fusion growth. These findings present the possibility of either (1) a synthesis process not yet explored by the gemological community or (2) growth by a known process, but with near perfection. While the DiamondView and Diamond Spotter were developed to analyze diamonds, they can also play a vital role in identifying other gemstones. @topic:3


Publish Year: 2018 Title: Update on Russian Demantoid Production Abstract: Figure 1. Russian demantoids are well known for their pure colors and remarkable inclusions. Photo by Kevin Schumacher.

Russian demantoids (figure 1) are renowned in the gem community for their pure, vivid colors and spectacular inclusions. Alexey Burlakov, founder of Tsarina Jewels, shared some insights on the current production of Russian demantoids and emeralds. Tsarina Jewels is based out of Bangkok and was co-founded with his father, Dr. Evgeny Burlakov, curator of the Ural Geological Museum in Yekaterinburg.

According to Burlakov, there are currently two mines in the Urals producing demantoid in commercial quantities: Korkodin and Poldnevaya. They are about 7 km apart, located in the same geological massif that also hosts numerous gold and platinum mineralizations. Although the two mines are very close to each other, the material is very different. The Korkodin mine is characterized by a darker color, often with a brownish tint that can be removed by heat treatment. Poldnevaya produces material of lighter, more “open” colors without the secondary brown. Because they are naturally a pure green, these demantoids do not require heating to optimize the color.

A third known deposit is Nizhny, located in the Tagil region about 200 km north of the other two mines. This was the original deposit where Russian demantoid was discovered, but it is currently inactive. The material from this mine typically has a lighter color with a slightly bluish tint, setting it apart from the other two.

Russian Demantoid Production
Alexey Burlakov of Tsarina Jewels gives insight into production of demantoid from two Russian deposits.
Russian demantoid comes in a wide range of colors, covering all shades of green. Much of the material has a brown color that can become dominant. The finest color is considered a pure, vibrant green with no secondary hues. It is estimated that around 80% of the Poldnevaya mine production has a secondary yellow color, while 15% is apple green and around 5% top vibrant green.

A typical feature of Russian demantoids is the horsetail inclusion, a radiating pattern of asbestos fibers. Fully developed horsetails are still rare. This inclusion has been found in demantoids from other localities as well, but none of these deposits match the importance of Russia’s.

The main markets for Russian demantoid are the United States, China, and France. The French market demands smaller melee-sized stones, while Chinese and U.S. customers opt for stones over 1 ct. Prices of Russian demantoid have increased, especially for larger sizes. This is due to the limited production. It is estimated that the Poldnevaya mine produces between 300 and 1,000 carats of gem-quality material per month. This means that only a few stones over 3 ct are produced on a yearly basis.

Other important gemstones from the Ural Mountains are emeralds and alexandrites. The Urals produced large volumes of emerald in the beginning of the 20th century. During the Soviet era, the mines were reopened for beryllium mining. In recent years, emerald mining has started again. New production and specimens have already reached the market. The Russian emeralds are generally lighter green but clean compared to other deposits. Alexandrite is not being mined, but a Russian government corporation is actively developing and expanding the alexandrite/emerald mines in the Urals. @topic:1


Publish Year: 1991 Title: Winter 1991 G&G Book Reviews Abstract: “Gemmology”
By Peter G. Read, 358 pp., illus., publ. by Butterworth-Heinemann, Oxford, England, 1991. US$65.00

“Gemstones and Their Origins”
By Peter C. Keller, 144 pp., illus., publ. by Von Nostrand Reinhold, New York, 1990. US$49.95

“Professional Goldsmithing”
By Alan Revere, 226 pp., illus., publ. by Van Nostrand Reinhold, New York, 1991. US$59.95

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


Publish Year: 1993 Title: Queensland Boulder Opal Abstract: After almost 75 years of inactivity, the deposits of boulder opal in Queensland, Australia, began to attract new interest in the 1960s and 1970s. Queensland boulder opal is found associated with the Winton formation, and results from deposition and dehydration of silica-rich solutions in an iron-rich host rock. At the Cragg mine, one of 69 known opal-mining operations in Queensland in 1991, miners drill as deep as 20 m to search for a deposit and then use open-cut methods to reach the opal-bearing layer identified. In the evaluation of boulder opal, color, pattern, and "composition" are important. Most boulder opal is stable under normal wear, and it is readily separated from its simulants. @topic:13


Publish Year: 2013 Title: Rare Double-Trapiche Emerald Abstract: The term “trapiche,” named after the Spanish word for the spoked wheel used to grind sugar cane, describes a very special growth phenomenon. Basic components usually include a six-ray star radiating from the center of the stone, a clear or dark hexagonal core at the center, and a transition between the core and the outer sectored crystal. It is commonly associated with emerald, but trapiche corundum, tourmaline, quartz, and andalusite are also found (T. Hainschwang et al., “Trapiche tourmaline from Zambia, Spring 2007 G&G, pp. 36–46). For the past 40 years, gemologists have tried to interpret this phenomenon, proposing theories that involve different growth rates and growth conditions.

Figure 1. These rare double-trapiche emerald slices, about 1.77 ct each, are from Muzo, Columbia. Courtesy of Equatorian Imports Inc. Photo by Eric Welch.
At the AGTA show, Equatorian Imports showed this contributor two pieces of emerald with a very rare double-trapiche pattern. They weighed about 1.77 ct each, and according to the dealer they are from Muzo, Columbia. Instead of a six-ray star, twelve arms radiated from the center of the stone (figure 1). There was no core at the center. The twelve-ray star appeared to be composed of two six-ray stars shifted slightly from each other. All the rays had a dendritic appearance, with some of them intertwined. Unlike previously reported trapiches, these two specimens displayed at least three growth sectors. The formation of this double-trapiche pattern was most unusual. @topic:1


Publish Year: 2017 Title: Cosalite in Quartz Abstract: Figure 1. This 16.20 ct quartz contains an abundance of inclusions. Photo by Kevin Schumacher.

A search of the gemological literature shows that rock crystal quartz contains a wide variety of unusual and interesting inclusions. Many of those inclusions look alike, so careful analysis is necessary for a positive identification. We recently examined a 16.20 ct cushion-shaped rectangular modified step-cut rock crystal from Kara-Oba, Betpaqdala Plateau, Kazakhstan (figure 1), that was fashioned by Michael E. Gray (Coast-to-Coast Rare Stones, Mendocino, California). Measuring 18.15 × 13.24 × 10.60 mm, it hosted several opaque silvery gray stalks and needles that appeared to have an orthorhombic morphology (figure 2). A fragment cut from the original rough crystal was analyzed by laser Raman microspectrometry and yielded a possible identification as cosalite, a rare orthorhombic lead bismuth sulfide. This was subsequently confirmed by X-ray powder diffraction. The discovery of such a rare mineral as an inclusion in this stone was a pleasant surprise.

Figure 2. Displaying an orthorhombic morphology, these inclusions were identified as cosalite. Photomicrograph by Nathan Renfro; field of view 4.11 mm. @topic:1


Publish Year: 1991 Title: New Rubies from the Morogoro Area, Tanzania Abstract: The authors present the mineralogical and gemological properties of rubies found recently in the Morogoro area of Tanzania that have many features in common with rubies from Myanmar (Burma) and other comparable marble-type deposits. Specifically, microscopic investigations of these Morogoro stones revealed some internal characteristics that are also seen in Burmese rubies-such as angular growth zoning, curved growth zoning ("swirls"), negative crystals, spinel crystals, rutile needles, and clouds of minute particles in areas defined by both types of growth zones, which may also be related to color zoning. However, the Morogoro material appears to have (1) lower amounts of V and Ga than Burmese rubies, and (2) a characteristic angular growth with r, a, and r' faces. A gemological comparison of the recently produced Morogoro rubies with rubies found earlier in this area shows significant differences. @topic:9


Publish Year: 2020 Title: Unusually Large Grandidierite Abstract: A green-blue translucent to semi-translucent grandidierite weighing 763.5 ct. Photo by Diego Sanchez.

The Carlsbad laboratory received a green-blue translucent to semi-translucent stone weighing approximately 763.5 ct and measuring 50.32 × 48.15 × 36.17 mm (see above). Standard gemological examination revealed a refractive index of 1.621–1.581, weak green-blue to green pleochroism, and absorption lines at 480 and 490 nm seen in the handheld spectroscope. Examination with a standard gemological microscope revealed the stone to be heavily included with fractures, fine particulate clouds, and miscellaneous whitish minerals. The results from Raman spectroscopy, microscopic observations, and standard gemological examination were consistent with the rare mineral grandidierite.
Named after French naturalist Alfred Grandidier (1836–1912), grandidierite is a very rare mineral first discovered in 1902 at the cliffs of Andrahomana on the southern coast of Madagascar (D. Bruyere et al., “A new deposit of gem-quality grandidierite in Madagascar,” Fall 2016 G&G, pp. 266–275). Gem-quality material of facetable size was not found in the market until after the summer of 2015 (Winter 2015 Gem News International, pp. 449–450). Grandidierite is found in various localities as an accessory mineral in aluminous boron-rich pegmatites and in rocks subjected to local high-temperature, low-pressure metamorphism such as contact aureoles and xenoliths (again, see D. Bruyere et al., 2016). It very seldom reaches large sizes, and this is the largest grandidierite GIA has seen to date. @topic:1


Publish Year: 2022 Title: Unusual Cat’s-Eye Omphacite Fei Cui Jade Abstract: Figure 1. This green omphacite fei cui jade (7.4 × 7.0 mm) displayed chatoyancy under fiber-optic light. Photo by Bowen Zhao.
A round cabochon set in a ring with round brilliant and rose-cut diamonds (figure 1) was recently submitted to the National Center of Quality Inspection and Testing on Gold-Silver Products (NGGC) for examination. The center stone, measuring approximately 7.4 × 7.0 mm in diameter, possessed a vivid green bodycolor and exhibited pronounced chatoyancy with a vibrant green sheen. FTIR analysis (figure 2) revealed that the stone was natural untreated omphacite-type fei cui jade, with a typical fingerprint spectrum corresponding with omphacite, a broad absorption band centered at 3500 cm–1 caused by the hydrous interstitial minerals, and the functional group region showing no absorption of any organic filling material commonly used in bleaching and filling treatment, such as Bisphenol A epoxy resin. Subsequent micro-Raman imaging and spectroscopic analysis confirmed the sample as a fairly pure omphacite aggregate, considering that no other mineral impurity was observed or identified (figure 3). The strongest Raman peaks at 682 cm–1 and 1023 cm–1 were attributed to symmetrical Si-Ob-Si stretching/bending and symmetrical Si-Onb stretching, respectively. Ob refers to the bridging oxygens, while Onb represents non-bridging oxygens in silicon tetrahedra.

Figure 2. Both the functional group region (left) and the fingerprint region (right) of the sample’s IR absorption spectrum were collected with a diffuse reflectance accessory. A K-K transform was applied to the fingerprint spectrum collected.

Figure 3. The sample’s Raman shift confirmed its mineral species. The sample matched well with the RRUFF spectrum for omphacite but differed considerably from the RRUFF spectrum for jadeite. The spectra are shifted vertically for clarity.
Element analysis with energy-dispersive X-ray fluorescence (EDXRF) showed that the sample’s major elements were silicon, calcium, aluminum, magnesium, and iron, consistent with omphacite, whose IMA formula is (Ca,Na)(Mg,Fe,Al)Si2O6). It is well known that the Fe2+-induced grayish bluish green bodycolor is most common among the green omphacite varieties. However, this chatoyant sample was characterized by a relatively high chromium content (Cr2O3 ≈ 0.22 wt.%), producing a more saturated and purer green bodycolor rather than a dull green one. This color feature was confirmed by UV-Vis-NIR spectroscopy, with only a single transmittance band centered at 535 nm appearing in the visible range (figure 4).

Figure 4. Two broad absorption bands centered around ~430 and ~650 nm were formed with the contributions of both iron and chromium. The 692 nm peak convincingly indicated the presence of Cr3+.
Microscopic observation with finely tuned fiber-optic light revealed a parallel-arrayed fibrous texture throughout the sample (figure 5). Meanwhile, a vague honeycomb-like pattern was observed at two specific sides near the girdle (the 12 and 6 o’clock positions of the cabochon in figure 1). Thus, under reflected light the stone presented a chatoyant sheen parallel to the ring band.

Figure 5. The omphacite fei cui jade’s parallel-arrayed fibrous texture (left) and vague honeycomb-like pattern (right), shown in fiber-optic illumination. Photomicrographs by Bowen Zhao; fields of view 10.45 mm (left) and 8.81 mm (right).
Based on our current knowledge, this green omphacite fei cui jade was probably from Guatemala. Translucent fei cui jade with such fine texture, vivid green bodycolor, and even color distribution has always been considered of high quality and rarity, but the chatoyancy of this sample offered additional value. @topic:9


Publish Year: 2023 Title: Vibrant Green Grossular Garnet “Transvaal Jade” Abstract: This 110.4 g partially polished rough grossular garnet “Transvaal jade” and three polished cabochons (41.95–92.87 ct) display unusually vibrant green colors between seams of dark chromite matrix. Photo by Diego Sanchez; courtesy of TMS Gems.
At the Pueblo show, Tom Schneider of TMS Gems (San Diego, California) offered “Transvaal jade” rough displaying an exceptionally vivid green color. Also known as “African jade” or “South African jade,” this is not a true jade (jadeite or nephrite). The stone is instead a grossular garnet whose trade name is derived from its massive habit and green color, and the type locality. Specimens of this material are typically more translucent and lighter in color (J. Frankel, “Uvarovite garnet and South African jade (hydrogrossular) from the Bushveld Complex, Transvaal,” American Mineralogist, Vol. 44, No. 5-6, 1959, pp. 565–591). Nested in a fine-grained chromite matrix, the opaque green portion of the stone in the figure above had a refractive index of 1.731 and was inert to both long-wave and short-wave ultraviolet radiation.
The sample was identified as grossular garnet using Raman spectroscopy and further classified as a grossular-andradite garnet using X-ray fluorescence chemical analysis and the naming convention proposed in 1995 (M.L. Johnson et al., “Gem-quality grossular-andradite: A new garnet from Mali,” Fall 1995 G&G, pp. 152–166). The chemical data show 80.83 mol.% grossular (Ca3Al2Si3O12), 10.50 mol.% uvarovite (Ca3Cr2Si3O12), 7.11 mol.% andradite (Ca3Fe2Si3O12), and trace amounts of other garnet. Garnets in the grossular to andradite range can show 4.64–20.91 wt.% Fe2O3 (Johnson et al., 1995) and typically have low chromium values (≤0.23 wt.% Cr2O3) (C.M. Stockton and D.V. Manson, “A proposed new classification for gem-quality garnets,” Winter 1985 G&G, pp. 205–218). Increased iron content will impart a yellow, orange, or brown color component, while the most intensely green stones owe their color to chromium and possibly vanadium (Johnson et al., 1995). The low iron content (2.49 wt.% Fe2O3) and elevated chromium content (3.50 wt.% Cr2O3) of this sample likely resulted in its remarkable coloration.
The chromium-rich nature of this particular specimen produced a beautiful vibrant green with a high-polish luster, making it an outstanding example of this material. @topic:9


Publish Year: 2008 Title: Copper-Bearing (Paraíba-Type) Tourmaline from Mozambique Abstract: Copper-bearing tourmaline from Mozambique was first recovered in 2001, but its Cu content was not recognized until 2003, and it was not widely sold with its Mozambique origin disclosed until 2005. It has been mined from alluvial deposits in an approximately 3 km2 area near Mavuco in the eastern portion of the Alto Ligonha pegmatite district. Most of the production has come from artisanal mining, with hand tools used to remove up to 5 m of overburden to reach the tourmaline-bearing layer. The stones exhibit a wide range of colors, typically pink to purple, violet to blue, and blue to green or yellowish green. Heat treatment of all but the green to yellowish green stones typically produces Paraíba-like blue-to-green hues by reducing absorption at ~520 nm caused by the presence of Mn3+. The gemological properties are typical for Cu-bearing tourmaline (including material from Brazil and Nigeria); the most common inclusions consist of partially healed fractures and elongate hollow tubes. With the exception of some green to yellow-green stones, the tourmalines examined have relatively low Cu contents and very low amounts of Fe and Ti. Mechanized mining is expected to increase production from this region in the near future.

	DATA DEPOSITORY

Electron-Microprobe Analyses of Tourmaline from Muva, Mozambique
	Submitted by Brendan M. Laurs
	Spring, 2008

Table 1: Average Chemical Composition of 59 Cu-bearing Tourmaline Samples from Mozambique
	Submitted by David Kondo
	Spring, 2008 @topic:9


Publish Year: 2013 Title: Unusual Faceted Massive Fuchsite Abstract: Figure 1. This massive Cr-muscovite, reportedly from southern Ethiopia, is better known in the trade as fuchsite. The longest rough piece measures 53 mm, and the faceted stone weighs 2.56 ct. The material was difficult to polish because of its low hardness, 3 or less on the Mohs scale. Photo by Thierry Pradat.

              French gem dealer Patrick de Koenigswarter (MinerK) recently showed us some interesting material he purchased in 2011 from an Ethiopian rough dealer. At the time of purchase, the green rough (figure 1) was presented to him as emerald from a new find near the Kenticha pegmatite zone in Ethiopia, well known for tantalite and superb amazonite crystals. However, beryl was ruled out due to the material’s waxy luster and low hardness of 3 or less on the Mohs scale—it was easily scratched with a copper coin.

Routine gemological testing was done on the four samples, which consisted of three rough pieces (17–138 ct) and a 2.56 ct emerald cut. The faceted stone (figure 1, bottom right) always remained lit under crossed polarizers, indicating a polycrystalline structure. The color was unevenly distributed, from light green to intense green, sometimes close to an emerald color. The refractive index, though difficult to measure, was around 1.60. The specific gravity values were 2.80 for two of the pieces and 2.90 for the others, a difference possibly due to the presence of mineral inclusions. All four pieces were inert under both long- and short-wave UV, and red to pink under a Chelsea filter. Additional analyses were required to properly identify this material.

Qualitative and quantitative analyses were performed with a JEOL-5800LV scanning electron microscope (SEM) equipped with a PGT (Princeton Gamma Tech) energy dispersive IMIX-PTS detector. The following elements were found (in atomic %): Si = 16.1%, Al = 17.0%, K = 4.0%, and Na = 1.3%; O was calculated as 61.0%, plus traces of Ba (0.3%), Fe, and Cr. These last two elements were clearly detected on the spectrum but in concentrations too low to be measured (below 0.1%). This composition is consistent with muscovite, a member of the mica family. We observed platy brown polyhedral inclusions, identified by EDS and Raman as rutile due to telltale broad bands around 611 and 443 cm–1.

	Figure 2. The UV-visible spectrum of the Ethiopian fuchsite shows a large absorption band around 600 nm, a continuum of increasing absorption toward the UV, and a weak, sharp peak at 682 nm. These features are consistent with green color produced by trivalent chromium.
We also performed UV-visible absorption spectrometry using a 1 nm sampling and spectral bandwidth in the 350–800 nm range. The spectrum showed a large band centered at about 600 nm and a continuum of increasing absorption toward the UV region (figure 2). These features generated two transmission windows, one in the green around 530 nm and the other in the red to infrared. This explains both the green bodycolor and the red appearance in the Chelsea filter. The continuum is caused by the scattering of light at grain boundaries in this polycrystalline aggregate. We also observed a weak but sharp peak at 682 nm, which we attributed to “chromium lines” of the trivalent chromium (figure 2, inset).

Chemical and spectroscopic results identified Cr3+ as the main cause of the green color. Hence, this material was fuchsite, the chromian variety of muscovite. To the best of our knowledge, this is the first time such a massive, translucent polycrystalline fuchsite has been faceted. The gem’s low hardness makes it unsuitable for jewelry, but it is adequate for collectors. @topic:1


Publish Year: 2013 Title: Canadian Mining Industry: Taking a Step Up with Range of Operations Abstract: The expansion of various mining projects in Canada’s North (Northwest Territories, Yukon, and Nunavut) is set to lead the country in economic growth over the next two years. Spinoff activity is also expected to increase, based on pending mines in the assessment phase or preproduction stage, further boosting employment and local economic development. Production in these areas is expected to last well into the coming decades. Environmental groups and local residents are also interested in the impact on the Canadian North ecosystem as well as the long-term effects on the towns and industry when the boom is over.

Abstracted by Michele Kelley @topic:9


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

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

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

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

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


Publish Year: 2017 Title: Preliminary Observations on Facet-Grade Ruby from Longido, Tanzania Abstract: Figure 1. Sixteen samples of facet-quality ruby (0.8–7.1 ct) from Longido, Tanzania. Photo by Sasithorn Engniwat.
With rubies discovered about 100 years ago, the Longido district of Tanzania is one of the longest-known occurrences in Africa. The deposit is famous for its “ruby-in-zoisite,” consisting of large red corundum crystals in a striking green zoisite matrix, often speckled with black amphibole spots. The majority is used for carving, but occasionally facet-quality material is discovered (D. Dirlam et al., “Gem wealth of Tanzania,” Summer 1992 G&G, pp. 80−102).

For this study, 16 transparent rubies (figure 1) were collected during a July 2016 field expedition. The stones were acquired at the Mundarara mine in Longido and from a dealer in a nearby trading post. Most of the rough material ranged from 1 to 3 ct, although one heavily fractured piece weighed about 7 ct. Colors ranged from red to purplish red, very similar to the color of high-quality Mozambican ruby. Fluorescence was medium red under long-wave UV and weak red under short-wave UV.

The inclusion scenes (figure 2) had features similar to those of rubies from Mozambique: short needles, particle banding, and reflective platelets (V. Pardieu et al., “Rubies from the Montepuez area, Mozambique,” GIA News from Research, Oct. 1, 2013).The most common inclusions were thin films (figure 2A), a combination of needles and reflective platelets (figure 2B) and particle banding (figure 2C). In addition, dense particulate planar clouds were arranged mostly parallel to each other and associated with short and long needles (again, see figure 2C). Internal growth zones (figure 2D) and twinning features were also found. Several types of crystals were identified by Raman spectroscopy, including amphibole, mica, and feldspar. Undetermined opaque metallic inclusions were also observed.

Figure 2. Internal features of ruby from Longido, Tanzania. A: A group of irregular thin films, field of view 1.6 mm. B: An array of reflective platelets with needles, field of view 0.9 mm. C: Short and long needles together with thin films; bands of fine reflective particles are also seen. Field of view 2.0 mm. D: Angular internal growth, field of view 4.0 mm. Photomicrographs by Boodsakorn Kongsomart.
Various advanced analytical techniques were used to characterize the properties of the studied rubies. Fourier-transform infrared (FTIR) spectroscopy revealed strong absorption features consistent with boehmite in all samples. Other minerals that are normally present in ruby, such as diaspore or kaolinite, were not detected in the studied rubies.

The trace element concentrations of these rubies were analyzed with laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) and compared to ruby from other East African sources (table 1). The rubies from Longido were extremely rich in Cr and fairly low in Fe compared to other African sources. The only East African deposit producing ruby with similar concentrations of chromophores is Maninge Nice in Mozambique, but the facet-grade material from Longido has lower magnesium content on average. Other deposits can be separated from Longido based on other trace elements (again, see table 1), although minor overlap cannot be excluded.

While Longido is traditionally known for large ruby-in-zoisite specimens, facet-grade rough is also produced and can yield attractive gemstones. Chemical analysis revealed an extremely high chromium concentration in both facet- and carving-grade ruby. While the internal features of the rubies from Longido are quite similar to those of other African deposits, trace element composition can aid in positively identifying their origin. @topic:9


Publish Year: 2016 Title: “Punsiri”-type FTIR Spectral Features in Natural Yellow Sapphires Abstract: Figure 1. Ten of the 38 basalt-related yellow sapphires from this study. The specimens on the left, weighing 0.22–0.41 ct, are from the Anakie area in Queensland, Australia. The material on the right, ranging from 0.41 to 1.40 ct, comes from the Khao Ploi Waen area of Chanthaburi, Thailand. Photo by Nuttapol Kitdee.

	Recently, a yellow sapphire from Chanthaburi, Thailand, showed a spectrum associated with “Punsiri” high-temperature heat treatment of blue sapphire. In response, GIA’s Bangkok lab performed FTIR spectroscopy on 38 untreated natural basalt-related yellow sapphires (figure 1). Twenty-two of the samples were from the Anakie Gem Fields area in Queensland, Australia, and the remaining 16 from the Khao Ploi Waen area of Chanthaburi. All were collected from the mines by GIA field gemologists.

	Standard gemological testing of the Australian sapphires showed RI (nω) = 1.774 ± 0.001 and RI (ne) = 1.765 ± 0.001, with a birefringence of 0.009 ± 0.001. For the Thai sapphires, RI (nω) = 1.773 ± 0.001 and RI (ne) = 1.764 ± 0.001, with a birefringence of 0.009 ± 0.001. All the stones were inert under long-wave and short-wave UV radiation due to their very high iron content.

	Most of the Australian sapphires were yellow, whereas the Thai sapphires appeared greenish yellow. Only homogeneous yellow areas were analyzed by FTIR. Many of the stones (about 45% of the Australian stones and about 38% of the Thai stones) showed a characteristic Punsiri FTIR spectrum, consisting of a multiple band structure positioned around 2000−3300 cm−1 with peaks at 2025, 2137, 2258, 2413, 2463, 2627, 2990, 3032, and 3220 cm−1 (figure 2). These features have traditionally been considered indicative of heat treatment, since this pattern has only been observed in Punsiri-type heated blue sapphires (G. DuToit et al., “Beryllium treated blue sapphires: continuing market observations and update including the emergence of larger size stones,” GIA Research News, June 2009) that display multiband FTIR spectra around 3000 cm−1. This FTIR feature is attributed to the stretching vibration of the OH bond formed by the incorporation of hydrogen and host oxide ion in a publication about “magnesium-doped α-alumina” grown by the Verneuil method, where the IR absorption results are affected by the incorporation of hydrogen into a Mg-doped α-alumina (N. Fukatsu et al., “Incorporation of hydrogen into magnesium-doped α-alumina,” Solid State Ionics, Vol. 162, 2003, pp. 147−159). Since the samples were all collected in the field, it is extremely interesting to document that Punsiri-type FTIR spectra may be found in natural unheated yellow sapphires.

	Figure 2. FTIR spectra of natural yellow sapphires from Australia and Thailand in the 1800–3600 cm–1 range. The peaks shown here are similar to those observed in Punsiri heat-treated blue sapphire (black spectrum). Peaks at 2360 and 2340 cm–1 are related to CO2. Please note that the absorption coefficient of the Punsiri heat-treated blue sapphire (black spectrum) at the y-axis was divided by two.

	LA-ICP-MS showed trace elements of Mg, Ti, V, and Ga, with very high ppm levels of Fe (3000 ppma on average). Mg content (about 23 ppma) was higher than Ti content (approximately 16 ppma); thus, blue coloration is not seen in these stones. Since Be was not detected, there are no concerns about beryllium diffusion treatment, which is not surprising since these specimens were collected in the field.

	It appears as though the incorporation of hydrogen in corundum may form characteristic Punsiri-like FTIR features. Since these features were observed in natural basalt-related yellow sapphires from Australia and Thailand, careful consideration must be exercised when using FTIR to identify heat treatment in corundum. @topic:3


Publish Year: 2020 Title: Uncommon Inclusion of Lazurite in Ruby from Mogok, Myanmar Abstract: Lazurite inclusion in Mogok ruby from Myanmar (transmitted light and oblique illumination). Photomicrograph by Kyaw Thu; field of view 0.25 mm.

A parcel of small rubies was received for identification at the S Gemmological Institute (SGI) gem lab in Yangon, Myanmar. Based on chemical, spectroscopic, and standard gemological testing, they were determined to originate from the Mogok Stone Tract in Myanmar. One faceted ruby contained a small blue crystal inclusion with what appeared to be a pyritohedron shape but an uncommonly seen bright blue color (see above). This inclusion was identified by Raman spectroscopy as lazurite.
A blue lazurite inclusion was previously reported to have been found in a 5.09 ct Burmese ruby and a 1.40 ct ruby from Namya, Myanmar (Spring 2012 Lab Notes, pp. 51–52). Also, blue lazurite mineral has previously been detected in 1.02 ct light gray Burmese spinel (Spring 2019 Micro-World, pp. 112–113).
According to the literature and our knowledge of inclusions in rubies from Mogok, this blue mineral is rare as an inclusion in Burmese rubies. @topic:1