# Publication Year: 2017
# Title: Lizard Skin on Deformed Diamond
# Abstract: Figure 1. A 2.67 ct oval-cut diamond with uneven “lizard skin” surface texture. Close-up views of the pavilion with reflected light show how the textured pattern continues across facet junctions. Photos by Evan Smith; fields of view 3.56 mm (center) and 1.29 mm (right).
Facets that are nearly parallel to a diamond’s octahedral crystal plane often develop a wavy, rippled appearance called “lizard skin” during polishing (e.g., J.I. Koivula, The MicroWorld of Diamonds, Gemworld International, Northbrook, Illinois, 2000, p. 63). The term is also used more broadly to describe any bumpy, uneven surface texture that develops on polished diamond facets. It is often attributed to polishing off-grain. Recently, GIA’s New York lab encountered a 2.67 ct type IIa diamond (figure 1, left) with especially prominent lizard skin texture on multiple facets (figure 1, center and right). In this case, the texture appears to have developed due to a preexisting deformation fabric or structure inherent to the diamond itself, rather than merely as a consequence of poor polishing technique.

The surface texture has a pattern to it, with small bumps appearing to line up in corridors. Some corridors clearly continue from one facet to the next (figure 1, right). The continuity across facets suggests that this texture is the surface expression of irregularities that actually extend into the volume of the diamond itself. At high magnification with crossed polarizing filters, the lizard skin can be seen to conform to the shape and texture of the strain pattern within the diamond—that is, the pattern of bumps and depressions matches up where the intricate internal dark/light pattern of tatami birefringence meets the polished surface. This connection supports the idea that the surface texture is a reflection of underlying crystal imperfections.

Unusual hydrogen- and methane-bearing metallic inclusions in this diamond suggest it originated from extreme depths of about 360–750 km in the earth’s mantle (E.M. Smith et al., “Large gem diamonds from metallic liquid in Earth’s deep mantle,” Science, Vol. 354, No. 6318, 2016, pp. 1403–1405). In this high-temperature environment, deformation and annealing over a long period of time may have given the diamond a mosaic crystal structure. This natural phenomenon occurs when heat allows the crystal to undergo recovery, a process of dislocation reorganization that divides the distorted grain into a mosaic of smaller, undistorted subgrains without new crystal growth. The subgrains, measuring about 10–30 microns, are like bricks in a wall; while the wall may be slightly curved, the individual bricks are not distorted. These distortions become localized as subgrain boundaries rather than spreading continuously through the crystal. As a result, the subgrains will be oriented in slightly different directions.

Because polishing is so strongly dependent on crystal orientation, if a single facet consists of a mosaic of subgrains with varying orientation, polishing will be uneven. The resulting surface may develop a pattern of bumps and depressions that mimics the size and shape of underlying subgrains and, in turn, reflects the diamond’s natural deformation history. Samples like this one are interesting for scientists because little is known about the geological conditions that lead to the various deformation-related features seen in natural diamonds. @chapter:29 @chapter:1 @chapter:29


# Publication Year: 2014
# Title: Dyed Green Marble Imitating Jadeite
# Abstract: Figure 1. This was claimed to be a high-quality piece of jadeite jade mounted in a yellow metal pendant. The oval cabochon measured 39.8 × 29.8 mm, exhibited a homogenous green color, and on first impression appeared to resemble jadeite. Photo by Lai Tai-An Gem Lab.

              A client of the Lai-Tai An Gem Lab in Taipei recently submitted for identification what was claimed to be a piece of fine jadeite mounted in a yellow metal pendant (figure 1). The oval cabochon measured 39.8 × 29.8 mm and exhibited a homogenous green color. At first glance, it bore a strong resemblance to jadeite. While dyes, polymer treatments, or a combination of the two are commonly applied to jadeite—and dyed green quartzite is sometimes used to imitate green jadeite and other materials such as glass and plastic—this piece proved to be dyed green marble with calcite as the main mineral. This was the first time dyed marble had been represented to us as jadeite.

Although marble is fairly abundant, calcite’s low hardness and easily visible cleavages do not make it a viable substitute for jadeite. Yet it does lend itself well to carving. Chinese merchants often sell untreated carved marble by the trade names “Hanbai jade” or “Afghanistan jade,” or even offer such material as “antique jade.” Jade, pronounced “yu” in Chinese, is a general term that typically applies to aggregates of minerals. Marble in the Chinese jewelry market is frequently fashioned into bangles and carved pendants, and some may subsequently be dyed or partially dyed to imitate jadeite jade. Although it was impossible to calculate the SG of this mounted specimen, calcite’s RI of 1.65 overlaps with jadeite jade’s, leading to the possible misidentification of such material (J.M. Hobbs, “The jade enigma,” Spring 1982 G&G, pp. 3–19).

	Figure 2. Raman peaks at around 1084, 712, 275, and 145 cm–1 were consistent with calcite.
The identification was determined using Raman and FTIR spectroscopy. The sample showed Raman peaks at around 1084, 712, 275, and 145 cm–1 (figure 2), with IR peaks at around 1445 and 878 cm–1. Microscopic observation revealed a network of dyed grain boundaries (figure 3). The dye treatment was confirmed with the spectroscope, where a single broad band typical of some green dyes was clearly evident in the red-orange region. Long-wave UV did not offer any distinction. Although destructive tests are always avoided, the client allowed us to gently scratch the surface with a metal pointer, which confirmed the material’s low hardness. This submission reinforces the need to consider all types of material when dealing with items resembling jadeite.

Figure 3. Microscopic observation revealed a network of dyed grain boundaries. Photo by Lai Tai-An Gem Lab; magnified 50×. @chapter:51 @chapter:4 @chapter:51


# Publication Year: 2017
# Title: Book Review: Hidden Gems: Jewellery Stories from the Saleroom
# Abstract: By Sarah Hue-Williams and Raymond Sancroft-Baker, 312 pp., hardcover, illus., publ. by Unicorn Press, London, 2016, US$50.00.

True stories sell. In Hidden Gems: Jewellery Stories from the Saleroom by Sarah Hue-Williams and Raymond Sancroft-Baker, 40 highly captivating and significant stories are recounted in celebration of the 250th anniversary of Christie’s auction house. Various chapters focus on Hollywood icons and their jewelry, the historical pieces of English lords and ladies, and designers important to the industry. The book includes details on important objects interspersed with homey tales of quiet personages simply wanting someone else to have their turn with beautiful jewelry.

The authors tell entertaining stories of Christie’s opening in Los Angeles in the mid-1990s. The multiple tales regarding the sale of the late Eva Gabor’s jewelry quickly grabs the reader’s attention, especially when documenting the auction house’s experiences with the world’s most glamourous executrix: Eva’s sister Zsa Zsa Gabor. Not only do you get to feel the dance of negotiations—“But dahlink, you know I always use Christie’s” while pursuing negotiations with other auction houses—we learn that the potential star of the auction, Eva’s diamond engagement ring, was nothing more than a glorious, eye-catching fake. The authors assure the reader that the faux piece was quickly pulled from the sale.

Balancing Hollywood glitz, stories abound in the elegantly composed book about English nobility quietly deaccessioning passé Victorian pieces, too-fussy Edwardian tiaras and stomachers, even artful Art Deco jeweled cases for a lady’s evening bag. No compilation of tales about an English auction house would be complete without a story or two about classically eccentric English ladies of means. The detailed conversation between a house-bound collector and Christie’s representative strike a resonant chord with anyone that has ever cultivated a sales relationship with a highly valued client, but the gemological history of her ever-increasing collection of Victorian jewelry also serves as a great teaching aid to interested readers. The Hull-Grundy collection, which an entire chapter is devoted to, explores the art of the cameo as executed by two famous artists, Fortunato Pio Castellani and Tommaso Saulino.

The authors go to great lengths to be accurate and fair when relating information about the gems and jewelry sold at Christie’s. The final section in the book carefully delineates gemological standards and information; these are indeed much like the sections within the auction house’s sales catalogues. The section then takes it a step further and gives the reader a tour of the world’s jewelry centers, including London’s Hatton Garden.

To hold your interest, all 40 stories in this cherished work are accompanied by high-quality photographs of the sold lots. There is an art to telling a story and an art to photographing jewelry; this book succeeds on both counts. The captivating snippets of the backstories of items in an auction catalog truly intrigue the reader. Until now, it was unclear that some of the pieces offered were the result of careful cultivation of the client after viewing their private menagerie. In particular, stories about customers coming to Christie’s with large diamonds wrapped in tissue pulled from pocketbooks strike a chord with this reader.

When you read this book—and you should—relish the way the stories flow in an intimate conversational manner, note the careful vetting of gemological lore and knowledge and, most importantly, admire the fact that if you work at Christie’s you want to pick up the phone. You never know what will be offered. @chapter:45 @chapter:2 @chapter:45


# Publication Year: 2014
# Title: The First Identified Non-Nacreous Beaded Cultured Pearl
# Abstract: Figure 1. A parcel of natural pen pearls surrounds a 6.92 ct non-nacreous beaded cultured pearl. Photo by Olivier Segura.

              The Laboratoire Français de Gemmologie (LFG) recently had the opportunity to examine a collection of non-nacreous pearls from the Pinnidae family (Pinna and Atrina species). Among these, one black pen pearl drew our attention for its relatively large size: a 10.6–10.6 × 9.6 mm round button weighing 6.92 ct.

Its dark black porcelaneous appearance was typical of pearls from the calcitic part of Atrina vexillum, the kind usually submitted for laboratory analysis (figure 1). Observation at 85× magnification (figure 2) revealed a distinctive pattern of convolution, with a few micro-cracks.

Figure 2. Surface magnification of the non-nacreous beaded cultured pearl revealed a typical calcitic pattern of pen pearls. Photo by Olivier Segura; magnified 85×.
Our findings on these cultured pearls are similar to those of N. Sturman et al. (“Observations on pearls reportedly from the Pinnidae family [pen pearls],” Fall 2014 G&G, pp. 202–215) in terms of Raman spectra (confirming the calcitic nature), UV-Vis spectra, and chemical composition.

The most interesting findings came from X-radiography. Microradiography/tomography imaging clearly shows a bright white disk inside the pearl (figure 3). The continuous separation line around this feature leaves no doubt that there is a bead inside the cultured pearl. As the beads used to nucleate “nacreous” pearls typically come from large freshwater mussels, we know that they are of a slightly denser material than saltwater nacre. Thus, they appear whiter than the surrounding material (of saltwater origin). The bead’s appearance was consistent with a classical nucleus of the kind used in bead-nucleated pearls. Measurement of the bead gave a 6.70 mm diameter.

Figure 3. This microradiograph clearly identifies the pen pearl as a beaded cultured pearl. Image by Olivier Segura.
Tomography confirmed the presence of a near-perfect spherical bead inside the cultured pearl. Even with the owner’s consent, however, we decided not to cut the pearl, as the imaging techniques were sufficient to prove the bead-cultured origin.

We wonder if this gem represents a single specimen achieved by a curious experimenter, or if there is now an industrialized process for cultivating such pearls. The cultivation technique used, even if it is known to produce cultured pearls in farms, requires advanced knowledge of the process. The owner reports having handled a black round pen pearl “the size of a golf ball.” From the size and symmetry and given this new discovery of a bead-cultured pen pearl, one can speculate that this too might be a bead cultured pearl.

This bead nucleation technique for unusual species could have easily been developed in the past. To our knowledge, though, this specimen represents the first non-nacreous beaded cultured pearl examined by a laboratory. Faced with the expansion of the bead culturing process and the possibility of successful trials in different mollusks, gemologists need to be very cautious in natural origin determinations, even when there is every reason to believe a pearl to be natural. @chapter:11 @chapter:4 @chapter:11


# Publication Year: 2008
# Title: The Wittelsbach Blue
# Abstract: The 35.56 ct Wittelsbach Blue is one of the largest historic blue diamonds ever fashioned. It belonged to the Bavarian House of Wittelsbach and was displayed in the Treasury of the Munich Residence until it disappeared in 1931. It was secretly sold in 1951, “rediscovered” in 1961, and then sold again in 1964 to an undisclosed private buyer. In December 2008, the Wittelsbach Blue was sold at Christie’s London to jeweler Lawrence Graff for just over $24.3 million, a record price for any diamond at auction. This article describes what is known about the Wittelsbach Blue since it was first reported in 1666, and the gemological information released to date on this diamond, which was recently graded Fancy Deep grayish blue. Investigations in the historical archives of Bavaria, Austria, and Spain revealed that there is no archival evidence to support many previous statements about this stone.

	DATA DEPOSITORY

Inventory of the Munich Treasury, 1774
	Winter, 2008 @chapter:41 @chapter:1 @chapter:41


# Publication Year: 2001
# Title: Pyrope from the Dora Maira Massif, Italy
# Abstract: Large pyrope crystals containing gem-quality portions have been collected since the early 1990s from the Dora Maira Massif, Western Alps, Italy. These crystals have yielded pale purple to purplish pink gemstones typically up to 1 ct. The chemical composition and physical properties compare favorably to those reported for near-end-member pyrope. Absorption spectra suggest that the color is related to Fe2+ and Mn2+. The pyrope formed in a mica schist-quartzite layer within Paleozoic basement rocks that underwent an Alpine high-pressure/low-temperature metamorphic event. The deposit appears extensive, but future production undoubtedly will be limited due to environmental restraints. Currently about 100 carats per year enter the marketplace. @chapter:7 @chapter:0 @chapter:7


# Publication Year: 2020
# Title: Blue Apatite in Pyrope-Spessartine Garnet
# Abstract: Figure 1. This 5.33 ct red pyrope-spessartine garnet was faceted by the author to display the unusual blue apatite crystal within. Photo by Diego Sanchez.

The author recently had the opportunity to examine and facet a piece of garnet rough. The garnet, reportedly from Madagascar, was acquired from gem cutter and dealer Desmond Chan of Los Angeles. The rough was selected for the unusual blue apatite crystal nearly reaching the surface. Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) chemical analysis indicated the rough to be a pyrope-spessartine variety. When orienting the stone in preparation for faceting, the author wanted the apatite inclusion to be the main focus of the gemstone. After slow and careful execution, a cut-cornered mixed-cut faceted gem was achieved, with the apatite eye-visible just under the table facet (figure 1). Oblique fiber-optic illumination was used to observe the world inside the gemstone, revealing a scene consisting of the blue euhedral apatite crystal paired with numerous iridescent intersecting needles of rutile (figure 2). This is one of the most unusual inclusions the author has seen in a garnet, and it is also notable as the gem was faceted to showcase the inclusion rather than hide or remove it.

Figure 2. A blue apatite crystal associated with intersecting iridescent needles was showcased. Photomicrograph by Jessa Rizzo; field of view 2.90 mm. @chapter:15 @chapter:0 @chapter:15


# Publication Year: -
# Title: Frozen Splendor: Gems and Minerals Near the Arctic Region
# Abstract: This stunning trove of colorful gems is found in remote areas near the arctic region. Glacier photo by Brendan Laurs/GIA. Photo illustration by Robert Weldon/GIA

	The glaciated peaks of the Arctic region set the stage for our gemstone quest − in an area that occupies less than 8 percent of Earth’s surface (from Greenland to Northern Europe, Russia and Canada) − to find these rarefied gems.

	Learn about gems from polar regions as we travel east from Greenland through Norway, Finland, Russia and Canada.

	We start our journey in Greenland, probably not on your list when thinking of colored gemstones, though hot red rubies have been found there. Most of Greenland’s gemstones have been found in a region that stretches 160 kilometers (km) (100 miles) along its southwest shores. The area first came to the attention of European scientists more than 200 years ago when they arrived to study the country’s geology. Native Greenlandic Inuit were already familiar with ruby, but tugtupite, another red gemstone, was discovered in 1957 at Tugtup Agtakôrfia on the north coast of Tunugdliarfik Fjord, South Greenland. Limited quantities of this rare gem make tugtupite a collector’s item. Sapphire, lapis lazuli, amazonite, peridot, quartz, spinel, topaz and tourmaline have also been found in Greenland, though not in commercial quantities or qualities.

Tugtupite, a collector’s stone from Greenland, is named after the location it was found, Tugtupit agtakôrfia. Tugtup means reindeer in Inuit. Courtesy of Ice Cold Gems, William Rohtert. Photo by Robert Weldon/GIA

	Traveling east about 3,200 km (2,000 miles) from Nuuk, the capital of Greenland, we come to the Kongsberg mines in southern Norway, where silver was discovered in the early 1600s in Buskerud County. The mines remained active for more than 330 years. They closed in 1958, but specimens from that locality are considered collector minerals. Today the town of Kongsberg houses the Norwegian Mining Museum, a collection of silver, tools and machinery used by miners, engineers and doctors. Emerald was mined from 1899 to 1909, and significant quantities of green beryl were mined in Byrud, Norway, in the late 19th and early 20th centuries at a working farm. Some of the material was transparent enough for faceting and today, the farm’s owner allows collecting on the mine area for a small fee.

Spectrolite, from Finland, is known for its broad flashes of strong color. Courtesy of True North Gems, Vancouver, B.C. Photo by Robert Weldon/GIA

	In Finland, 1,400 km (870 miles) east of Norway, we find exceptional labradorite (known in the trade as spectrolite), in a small area of the southeastern region. Spectrolite’s strong, broad flashes of color are reminiscent of the colorful and dramatic Aurora Borealis, which can be seen for more than six months of the year in Finland. Finland is the classic source for labradorite, however, the gem was named for Labrador, Canada where it was first discovered.

	Proceeding in an easterly direction, we pause in the Ural Mountains of Russia, a rich source of colored gemstones long accessed by Russian nobility for use in its imperial jewelry designs. Here we find a large variety of gems: emeralds, amethyst, aquamarine, demantoid garnets, jadeite, yellow beryl, malachite, jasper and alexandrite. Russia is the classic source for alexandrite, which was named for Czar Alexander II of Russia.

View Gallery

	The next destination takes us to Yakutia, in the frozen tundra of Siberia, 20 km (12 miles) south of the Arctic Circle. This is the land of polar nights where the sun never shines for days in winter. Mir Mine, the world’s largest known open pit diamond mine, was discovered in 1955 by Soviet geologists. It sits at the site of a volcanic pipe that contained trillions of carats of diamonds. The Mir Mine, worked sporadically until 2011, is closed. In its heyday in the 1960s, millions of carats of gem quality diamonds were produced annually. In 1980, a 342.57 carat fancy lemon yellow diamond was found in the Mir Mine. It now resides in the Russian Diamond Fund, Moscow Kremlin.

	Canada is the final destination in our odyssey for polar gems. The geological conditions in British Columbia are similar to the conditions in Myanmar and China, the top two producers of jadeite. An 18-ton nephrite boulder, Polar Pride, was discovered at the Polar Jade Mine in British Columbia. Half of the Polar Pride boulder was carved into the famous 4.65-ton Jade Buddha for Universal Peace in Thailand over a two-year period. It is approximately 2.5 meters (about 8 feet) tall − the largest Buddha ever carved from gem-quality nephrite. The jade Buddha has been on a tour of more than 15 countries since 2009 to inspire people to seek peace in their lives.

This collector specimen from Calgary, Alberta, Canada is an extinct fossilized ammonite shell in matrix. Similar rough would be fashioned into cabochons for jewelry and sold as ammolite. Gift of Korite International. Photo by Kevin Schumacher

	Southern Alberta is a source of ammonite, a fossilized extinct group of marine animals related to modern day cephalopods, such as the squid, octopus and nautilus. They lived 200–65 million years ago, becoming extinct along with the dinosaurs. Most ammonite fossil shells are treated with a colorless hardened substance to increase stability. Some shells show very strong iridescence when polished. They are fashioned into jewelry and known as “Ammolite” in the trade.

	The eastern regions in Canada’s Northwest Territories near the Arctic Circle share a climate similar to the Mir Mine in Siberia, Russia. The relatively new Ekati and Diavik diamond mines, located 300 km (186 miles) from Yellowknife in the Lac de Gras region, are renowned for producing premium quality diamonds that are often marketed as “conflict-free” diamonds. Canada also produces an array of colored gemstones and crystal specimens.

	Our journey through the polar regions of northern continents reveals a richness of gems and minerals that are sure to warm your soul. @chapter:1 @chapter:0 @chapter:1


# Publication Year: -
# Title: Tanzanite Care and Cleaning Guide
# Abstract: With proper care to avoid hard blows, tanzanite can be worn in all styles of jewelry. - Courtesy Tanzanite Foundation ™

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

	Tanzanite ranks 6 to 7 on the Mohs scale.
Zoisite (tanzanite) is 6 to 7 on the Mohs scale. It has fair to poor toughness and a property called cleavage, which is a tendency to break when struck. While tanzanite is not as hard or as tough as a stone like sapphire, it still can be worn in all types of jewelry with proper precautions against rough wearing or hard blows.

Stability
Tanzanite is stable under normal wearing conditions, which means it’s resistant to the effects of heat, light, and common chemicals. Even so, tanzanite should not be subjected to very high temperatures or sudden temperature changes. It can be attacked by exposure to hydrochloric and hydrofluoric acids.

Cleaning
Warm, soapy water is always safe. Ultrasonic and steam cleaners are never recommended for tanzanite

Treatment and durability considerations
Tanzanite is routinely heat-treated to modify its color from a predominately brownish appearance to a predominately blue to purple appearance. The treatment is stable with no additional durability concerns.

There have been instances where tanzanite was coated to modify the color. Although rarely done, the coatings are not permanent and can be scratched or damaged through normal wear.

Like other transparent gemstones, tanzanite can be fracture filled to improve apparent clarity, although this is an uncommon tanzanite treatment method. The materials used to fill fractures in gemstones can alter in appearance over time. @chapter:2 @chapter:0 @chapter:2


# Publication Year: 2008
# Title: Winter 2008 Gem News International
# Abstract: Colored Stones and Organic Materials
	            Visit to Andesine Mines in Tibet and Inner Mongolia
	            Gemological Properties of Andesine Collected in Tibet and Inner Mongolia
	            New Find of Vivid Kunzite from Pala, California
	            Natural Pearls of the Veneridae Family
Synthetics and Simulants
	            Synthetic Citrine with Abundant Nail-Head Spicules
	            Radiocarbon Dating of “Neptunian” Beads from Asia Proves Modern Origin
	            Purplish Blue Synthetic Quartz
Treatments
	            Dyed Chalcedony Resembling Chrysocolla
Miscellaneous
	            Update on U.S.-Myanmar Import Restrictions
Announcements
	            Starting with this issue, the conference and exhibit calendars will only appear online.

To view the full section, download the PDF above.

	DATA DEPOSITORY

Visit to Andesine Mines in Tibet and Inner Mongolia - Supplementary Photos
	Submitted by A. Abduriyim
	Winter, 2008

Gemological Properties of Andesine Collected in Tibet and Inner Mongolia - Supplementary Photos
	Submitted by A. Abduriyim and T. Kobayashi
	Winter, 2008 @chapter:6 @chapter:0 @chapter:6


# Publication Year: 2003
# Title: An Investigation into the Cause of Color in Natural Black Diamonds from Siberia
# Abstract: Black and dark gray diamonds from Siberia, Russia, were studied by analytical scanning and transmission electron microscopy. Their color is caused by the presence of dark inclusions. Unlike some previous reports on black diamonds in which the dark inclusions were primarily graphite, the Siberian samples with the most intense black color contained predominantly magnetite inclusions, while the dark gray diamonds most commonly contained inclusions of hematite and native iron. Moreover, the black diamonds studied exhibited anomalously high magnetic susceptibility, which may serve as one criterion for determining the natural origin of black color. @chapter:39 @chapter:1 @chapter:39


# Publication Year: 2010
# Title: X-ray Computed Microtomography Applied to Pearls: Methodology, Advantages, and Limitations
# Abstract: X-ray computed microtomography reveals the internal features of pearls with great detail. This method is useful for identifying some of the natural or cultured pearls that are difficult to separate using traditional X-radiography. The long measurement time, the cost of the instrumentation, and the fact only one pearl at a time can be imaged are some of this method’s disadvantages.

	DATA DEPOSITORY

	Supplementary Videos and Images (see below)
	Summer, 2010

Depository Item 1

	Figures 1a, 1b, 1c3D model of Beaded Saltwater Cultured Pearl

	Videos showing slices taken in three directions through the 3D model of the beaded saltwater cultured pearl in figure 4 (sample GGL19). All sections show reconstruction artifacts due to rotation: fine circles in the horizontal section (a) and a blurry rotation axis in perpendicular sections (b and c).

Depository Item 2

	Figures 2a-2f3D model of Non-beaded Saltwater Cultured Pearl

	Videos showing slices taken in three directions of the 3D model (with and without shadows) of the non-beaded saltwater cultured pearl in figure 5 (sample SK-51). In the videos b, d, and f, structures produced by the grafted tissue have an inverted color; that is, these structures appear dark in the original videos (a, c, and e) instead of bright. All sections show reconstruction artifacts due to rotation.

Depository Item 3

	Figures 3a-3c3D model of Freshwater Natural Pearl

	Videos showing slices in three directions of the 3D model of the freshwater natural pearl in figure 6 (sample GGL03). All sections show reconstruction artifacts due to rotation.

Depository Item 4

	Figures 4a-4c3D Model of Saltwater Natural Pearl

	Videos showing slices in three directions of the 3D model of the saltwater natural pearl (sample SK-46) presented in the figure 7. All sections show reconstruction artifacts due to rotation.

Depository Item 5

	In this (a) gray-black half-drilled, drop-shaped, non-beaded freshwater cultured pearl
	from Hyriopsis spp. (sample SK-54), a characteristic comma-shaped structure caused
	by the grafted tissue was only visible in one direction in the radiographs (b). Tissue-related
	structures (i.e., undulating growth lines) are clearly visible only in the μ-CT images (c, d).

	Figures 5e-5j3D Model of Non-beaded Freshwater Cultured Pearl

	The videos show slices in three directions of the 3D model of this sample. In the videos b, d, and f, the tissue-related structures are shown with inverted colors (they appear bright). All sections show reconstruction artifacts due to rotation.

Depository Item 6

	In this near-round, non-beaded freshwater cultured pearl (a) from Hyriopsis spp.
	(sample GGL26), a mixture of structures representative of a cultured pearl are observed
	in the radiograph (b). The μ-CT images (c, d) suggest that these structures are related
	to more than one piece of grafted tissue.

	Figures 6e-6j3D Model of Non-beaded Freshwater Cultured Pearl

	This is more evident in two of the videos (f and j), where the tissue-related structures are shown with inverted colors (they appear bright). Photo by A. Spingardi. All sections show reconstruction artifacts due to rotation.

Depository Item 7

	These 3D μ-CT images of a half-drilled, drop-shaped, saltwater natural pearl from Pteria spp. (sample SK-61) show the pearl mounted (left) and unmounted (right). The metal produces artifacts that partially mask the internal features; the structures indicative of a natural origin are much more visible in the unmounted pearl. @chapter:11 @chapter:4 @chapter:11


# Publication Year: 2015
# Title: Three Unique Large Natural Pearls from Haliotis (Abalone) Species
# Abstract: Figure 1. Three unique abalone pearls are shown alongside a typical 12 mm golden South Sea bead-cultured pearl for comparison. Photo by Sood Oil (Judy) Chia.

Natural abalone pearls are produced by many species of the Haliotis genus, which are ear-shaped saltwater univalve gastropods. They may form in many different sizes and shapes, though they are commonly encountered in baroque shapes, often taking the form of elongated “horns” and “teeth.” The pearls are also notable for their high luster and attractive multicolored appearance, which is usually dominated by blue, green, or yellowish green bodycolors. GIA has reported on many Haliotis pearls in previous Lab Notes over the years (Fall 1984, p. 169; Spring 1996, pp. 47–49; Fall 2004, pp. 259–260; Spring 1993, p. 51).

Three large and unique abalone pearls from a client’s collection were recently submitted to the New York laboratory (figure 1). Each piece was remarkable in its own right. A button-shaped pearl, measuring approximately 26 × 24 mm with impressive vivid “peacock” blue and green hues, was set in a yellow metal brooch. The second piece, seen in figure 1 on the far right, was a loose abalone pearl weighing 66.83 ct and measuring approximately 42 × 26 × 19 mm with a striking resemblance to a fish’s head. The eye, mouth, and gill features were clearly outlined in the specimen, which possessed a smooth surface and subtle array of iridescent greenish yellow colors. The third piece, weighing 113.58 ct and measuring approximately 62 × 29 × 16 mm, was also loose and resembled the head of a snake. It exhibited strong iridescence with mottled patches of various colors similar to the pattern observed on the scaly skin of snakes.

Figure 2. All three specimens from figure 1 showed concentric and void-related internal structures typical of abalone pearls. Images by Surjit Dillon Wong.
Microradiography revealed characteristic Haliotis-related voids with concentric growth structures in all three pearls (figure 2). Two of the pearls also revealed an iodine-rich composition, which GIA has noted is a fairly consistent property of abalone pearls. Such internal structures, along with their distinctive multicolored orient, bubble-like (botryoidal) subsurface structure (figure 3), interesting chemical composition, and chalky greenish yellow fluorescence under long-wave UV are all characteristic of abalone pearls.

Figure 3. This photomicrograph shows the patches of color and botryoidal-like subsurface
structure characteristic of abalone pearls. Photomicrograph by Joyce Wing Yan Ho;
field of view 3.9 mm.
The various shapes are determined by where the pearls are formed within the body of the mollusk, and often mirror the form of the gonad (E. Strack, Pearls, Ruhle-Diebener-Verlag GmbH & Co. KG, Stuttgart, 2006). Examining all three specimens at the same time allowed us to see a range of colors and shapes possible in abalone pearls. We look forward to encountering more of these unusual pearls. @chapter:11 @chapter:4 @chapter:11


# Publication Year: 2022
# Title: Blue Apatite in Tanzanian Garnet
# Abstract: Blue apatite crystals are beautifully framed by prominent rutile needles in a garnet from Tanzania. Photomicrograph by E. Billie Hughes; field of view 3.5 mm.
In the micro-world, it can be challenging to identify inclusions based on sight alone, as many minerals can have a similar appearance. Occasionally, though, some inclusions have characteristic features that can aid in their identification.
Recently this author had the opportunity to observe a pyrope-spessartine garnet, reportedly from Lindi Province, Tanzania, that contained blue crystal inclusions ensconced among intersecting needles (see above). Analysis with micro-Raman spectroscopy identified the inclusions as apatite. Apatites are known for their bright blue hues, and these inclusions offered an attractive example.
While this sample hails from Tanzania, blue apatite has previously been reported as an inclusion in garnet from Madagascar (Winter 2020 G&G Micro-World, p. 526). These inclusions’ distinctive appearance may help gemologists recognize the material in other samples, but further analysis should be performed to identify them definitively. @chapter:12 @chapter:0 @chapter:12


# Publication Year: 2019
# Title: Iolite-Sunstone Intergrowth and Inclusions
# Abstract: Figure 1. An iolite-sunstone overgrowth crystal specimen. Photo by Kevin Schumacher.

At the GIA Carlsbad laboratory, the authors recently examined a cabochon of “bloodshot” iolite (containing red, eye-visible platelets of hematite) intergrown with a sunstone (figure 1). This material was reportedly sourced from India. Cordierite (iolite) and plagioclase feldspar is a common metamorphic mineral assemblage, and similar material reportedly from India has been documented in the past (Winter 1991 Gem News, pp. 261–262).
This “double” gem specimen displays a mixture of an attractive bluish violet dichroic color with red hematite platelet inclusions in the iolite half, combined with an orange aventurescence effect from numerous tiny copper-colored hematite platelets in the sunstone half.

Figure 2. This colorful inclusion scene showcases an anthophyllite crystal inclusion, which exhibits high transparency, several cleavage planes, and a thin/bladed prismatic crystal form. Photomicrograph by Jonathan Muyal; field of view 2.34 mm.
Viewing the stone under magnification offers an inclusion scene with a variety of well-formed hematite platelets, crystals, and liquid inclusions. Of particular interest was a fine elongated single-crystal inclusion of anthophyllite (figure 2).
The crystal shape of the anthophyllite could easily be mistaken for phlogopite, which has been documented in cordierite (E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gems, Vol. 1, ABC Edition, Zurich, 1986, p. 268). In fact, several greenish brown prismatic phlogopite crystal inclusions were also observed inside the same specimen. Nevertheless, the anthophyllite crystal was conclusively identified by Raman microspectrometry analysis. The anthophyllite crystal inclusion showed a bladed prismatic crystal form, orangy yellow color, transparency, and several cleavage planes.
Although amphibole mineral inclusions have been documented extensively, distinct prismatic anthophyllite crystal inclusions are very rare and few references are found in the literature. Anthophyllite is more common in lamellar or fibrous form, classified as asbestos.
This combination iolite-sunstone specimen and its inclusions offer a unique visual composition that makes it a desirable piece for a gem collection @chapter:15 @chapter:0 @chapter:15


# Publication Year: 2023
# Title: The Special Color Effect in “Chameleon” Amber
# Abstract: Figure 1. A good-quality 88.25 ct “chameleon” amber with a red bodycolor displaying a vivid green fluorescence color that appears to float on the surface. Photo by Yan Li.

Figure 2. A and B: A 78.51 ct chameleon amber exposed to white light against white and black backgrounds. C and D: A 12.50 ct brownish reference sample exposed to similar lighting and backgrounds. Photos by Jinfeng Yang.
One special variety of Burmese amber is “chameleon” amber, named for the bluish green color that appears to float on its surface (figure 1). This material is found in the famous Tengchong market in Yunnan Province, China’s largest Burmese amber market. Its bodycolor ranges from golden brown to brownish red or even red (figure 2A). When exposed to sunlight or strong white light against a black background, its surface shows a uniform green color (figure 2B). Chameleon amber is rare and expensive compared to regular Burmese golden or brownish amber, especially with the severe reduction of exports from Myanmar.
Until recently, few studies have been conducted on chameleon amber. X. Jiang et al. speculated that the green surface color might be caused by the superposition of its bodycolor and the fluorescence of amber (“Gemmological and spectroscopic characteristics of different varieties of amber from the Hukawng Valley, Myanmar,” Journal of Gemmology, Vol. 37, No. 2, 2020, pp. 144–162). C.C. Shuai et al. proposed that the “light retention” effect was related to elevated sulfur and calcium contents (“The spectrum characteristic research of color change effect and ‘light tarry effect’ amber from Burma,” Spectroscopy and Spectral Analysis, Vol. 40, 2020, pp. 1174–1178). Z. Shi et al. reported that the effect might be due to unique internal aromatic hydrocarbon structures (“Spectral characteristics of unique species of Burmese amber,” Minerals, Vol. 13, No. 2, 2023, article no. 151).

Figure 3. A and B: A 71.05 ct Burmese chameleon amber and its bluish white fluorescence under long-wave UV light. C and D: 16 mm brownish Burmese amber beads (12.60 ct on the left, 12.16 ct on the right) and their bluish purple fluorescence under long-wave UV. Photos by Jinfeng Yang.
For this study, three Burmese chameleon amber specimens were acquired from the Tengchong market (see figures 1, 2A, and 3A). All three displayed a translucent brownish red bodycolor, with a few bubbles and flow lines within them. The bluish green floating color was observed when the specimens were rotated. This phenomenon is most obvious with a black background. Standard gemological properties and Fourier-transform infrared spectroscopy data were consistent with those of regular Burmese amber. While the bluish green floating color might be related to fluorescence, no such effect is seen on other types of fluorescing Burmese amber (e.g., brownish amber). To further explore this, brownish Burmese amber beads with bodycolor similar to that of chameleon amber were selected as a reference (figures 2C and 3C). Their bodycolor was not as vivid as chameleon amber, and it did not display the bluish green floating fluorescence. Observation under a UV lamp showed that the chameleon amber in figure 3A produced strong bluish white fluorescence (figure 3B) in long-wave UV (365 nm), while the brownish amber beads in figure 3C showed a weak bluish purple fluorescence (figure 3D).

Figure 4. 3D fluorescence spectra of Burmese chameleon amber (A) and brownish amber (B).
The samples were then examined with 3D fluorescence spectroscopy (figure 4) under the excitation of a continuous-wavelength excitation light source. The fluorescence intensity of brownish amber was clearly much lower than that of chameleon amber. In addition, two peaks (455 and 384 nm) were absent in the excitation spectrum of brownish amber. A high degree of similarity was exhibited in the samples’ emission spectra, with all the peaks positioned at approximately 434, 464, 469, and 497 nm. However, the biggest difference was in the fluorescence intensity, which was easily observed in chameleon amber.
The 3D fluorescence spectra of chameleon amber exhibited several fluorescence centers, mainly at 434, 464, 469, and 497 nm generated by excitation wavelengths of 386, 406, 436, and 457 nm. The fluorescence color could be calculated by the fluorescence centers, and the results showed that the spectral color was blue under 386 nm excitation and bluish green under 436 nm excitation. We believe that the bluish green floating color under sunlight is caused by the bluish green fluorescence center at 469 nm under 436 nm excitation. This is much more consistent with observations in daylight. Due to the low fluorescence intensity of brownish amber, its blue fluorescence color is very weak, and most light penetrates it without producing any special optical effect. The difference in fluorescence intensity between the 469 and 434 nm fluorescence centers corresponds with the relative spectral power distribution of the light source. Under the excitation of a xenon lamp, the fluorescence center at 434 nm is more intense than the light-emitting center at 469 nm. However, amber is usually observed in daylight. The optimal excitation wavelengths for the emission centers at 434 and 469 nm are 386 nm and 436 nm, respectively. From the relative spectral power distribution of the two light sources, it can be seen that the spectral density of the xenon lamp at 386 nm is greater than 436 nm, while the D65 daylight-equivalent source is the opposite. Against a dark background and under daylight, the fluorescence of chameleon amber should be dominated by the bluish green fluorescence emitted at 436 nm.
The fluorescence center at 469 nm is very common in Baltic, Dominican, Mexican, and Burmese amber. This fluorescence center in chameleon amber is unique for its high intensity and separation from other fluorescence colors. Only if the fluorescence intensity is high enough will it show as the dominant fluorescence color. The optimal excitation wavelength (436 nm) corresponding to the 469 nm fluorescence center is far removed from the optimal excitation wavelength of other strong fluorescence centers; therefore, the fluorescence color is not a mixture of multiple colors. Many varieties of amber can also produce strong fluorescence at 469 nm, but often mixed with other fluorescence colors of similar intensity. For example, the fluorescence peaks of 448 and 474 nm in Dominican blue amber always appear together, and their strong fluorescence peaks can be seen with exposure to the same excitation wavelength. In most cases, the fluorescence intensity of the former is slightly greater, which leads to the fluorescence of the blue amber being mainly blue, without a green modifier. Some Dominican blue amber with uneven fluorescence distribution can also show a mosaic pattern (X. Chenxing et al., “Characterisation of patchy blue and green colouration in Dominican blue amber,” Journal of Gemmology, Vol. 37, No. 7, 2021, pp. 700–713). The fluorescence distribution of the chameleon amber tested in this study was uniform, with high intensity and good separation, producing a high-quality bluish green floating fluorescence effect. @chapter:46 @chapter:0 @chapter:46


# Publication Year: 1988
# Title: Examination of Three-Phase Inclusions in Colorless, Yellow, and Blue Sapphires from Sri Lanka
# Abstract: Three-phase inclusions in untreated natural colorless, yellow, and blue sapphires from Sri Lanka were found to consist of liquid and gaseous carbon dioxide as well as needle-like to tabular crystals of diaspore. The identification of diaspore was accomplished through the use of a microscope-mounted drill system and an improved version of the Gandolfi X-ray camera. Technical details for both methods are given. The conditions under which diaspore forms as a daughter mineral in corundum are briefly discussed. @chapter:24 @chapter:0 @chapter:24


# Publication Year: 2014
# Title: Unusual Optical Effect in Blue Sapphire
# Abstract: Figure 1. This 1.36 ct light bluish violet sapphire displayed an interesting color shift when exposed to the UV radiation of the DiamondView. Photo by Igor Iemelianov; magnified 15×.

              A 1.36 ct light bluish violet sapphire (figure 1) was presented to the laboratory of the State Gemological Center of Ukraine for examination. The stone exhibited an RI of 1.762–1.770, with a birefringence of 0.008, and a hydrostatic SG of 3.97. The samples displayed typical pleochroism and a very weak pinkish orange fluorescence to long-wave UV. Qualitative analysis using EDXRF spectroscopy showed major amounts of Fe, Cr, and Mg, and minor amounts of Ti and Ga. Microscopic examination revealed dot-like dissolved rutile, proof of heat treatment. The sapphire showed a small color shift from bluish violet in the daylight to pale blue in incandescent light. A band with pink luminescence (apparently due to Cr3+ impurity) was identified using the DiamondView (figure 2). When removed from the DiamondView, the stone had completely changed color to brown (figure 3, left). After about 15 minutes in natural daylight, the light bluish violet hue began to return (figure 3, right). About 12 hours later, its original blue-violet color was restored. Such color instability is extremely unusual in blue sapphires.

	Figure 2. The DiamondView recorded this band with pink luminescence in the light bluish violet sapphire. Image by Igor Iemelianov.

	Figure 3. When removed from the DiamondView, the sapphire had completely turned brown (left). After about 12 hours, the stone reverted to its original light bluish violet color (right). Photos by Igor Iemelianov, magnified 15×.
It should be noted that the UV lamp in the DiamondView has a wavelength less than 225 nm (according to the user’s manual). The energy of UV radiation is considered too weak for the color treatment of corundum (see K. Nassau, Gemstone Enhancement, Butterworth-Heinemann, 1984, p. 221). In this sapphire, the DiamondView apparently caused the color change. Such a reversible change of color with exposure to light is called photochromism. @chapter:19 @chapter:1 @chapter:19


# Publication Year: 2023
# Title: New Tourmaline Pockets in San Diego County’s Pala District
# Abstract: Figure 1. A 16.96 ct emerald-cut green tourmaline from rough found near a new pocket at the Tourmaline King mine. Photo by Robert Weldon; courtesy of Pala International.
At the AGTA show, Bill and Carl Larson (Pala International, Fallbrook, California) shared details about new pockets uncovered at the Tourmaline King mine. The first was discovered in January 2022—the first major find at the mine in more than a hundred years, and the first in Southern California since the “Big Kahuna” pocket at the Oceanview mine in 2010. “We’ve hit off and on three or four pockets, some of which are very good,” Bill said.

Figure 2. Rubellite tourmaline rough (440 g) from one of the Tourmaline King mine’s new pockets. Photo by Robert Weldon; courtesy of Pala International.
The Larsons showed us several stones, including a 16.96 ct emerald-cut green tourmaline (figure 1) from rough found near the first pocket in 2022. Bill said the green tourmaline is relatively uncommon for the Pala District. “The green has actually been transparent enough to facet,” Carl added. “That’s been the best material so far.” The new pockets have also produced about 3 kg of fine-color rubellite rough (figure 2).
The Tourmaline King mine’s main tunnel produced eight tons during San Diego County’s massive output of tourmaline in the early nineteenth century, which also involved the Pala District’s Tourmaline Queen, Pala Chief, and Stewart mines, as well as Mesa Grande’s Himalaya mine. (There was a resurgence of mining at Pala in the 1970s.)
Around 1920, mine owner R.M. Wilke and his crew installed a new tunnel below the main one. “They hit this very dangerous zone right before they hit the pegmatite,” Bill said. Here they encountered a shear zone that caused a roof collapse. Wilke abandoned mining efforts around 1922.
Pala International’s mining partner, San Diego Mining Company, reclaimed the tunnel several years ago and began extending it in 2019. “They got to the dangerous area, and then they backed up about 10 meters and went around and hit the pegmatite,” Bill said. “Now they’re in from the front to the back, where we’re hitting tourmaline.”
Carl recalled his initial look at the first new pocket. “Kiel Snyder stopped me and said, ‘Everyone else gave up here,’” he said. “He just believed in it and kept going. Then they hit a small pocket—nothing of note, but something that said, ‘There are stones here.’ I think they called that the ‘Never Give Up’ pocket. Within 10, 15 feet, they hit that first pocket.”
The crystals were large and well formed, and the miners uncovered a very large terminated quartz crystal, a collector specimen. Carl said the crystals in this pocket lack the rubellite color and are not typical of the mine, making them inadequate for cutting and cabbing. But in January of 2023, they discovered a pocket of beautifully colored red rubellite, too included for faceting but suitable for cabbing and carving. “We’re hoping that we’ll hit some more gemmy transparent material,” he said.
“It’s really exciting to have an active mine in Southern California because of its rich history,” Carl said. “At the turn of the century we were hitting a lot, and then it was vacant for so long. So to have some energy coming in with new material is exciting.” @chapter:30 @chapter:0 @chapter:30


# Publication Year: -
# Title: The Stories Behind the Photos: A Gigantic Aquamarine and ‘Gaudy’ Nature
# Abstract: The tools of a traveling field photographer include a map, notebook, pen, mobile phone with compass app and a digital camera. Photo by Robert Weldon

Robert Weldon has traveled the world in pursuit of the most fascinating and beautiful gemstones as a gemological photojournalist. He has climbed into mines, trekked miles to the next location and waited patiently for the perfect light. He is as enthralled with the people who mine and deal with gemstones as he is with the places and cultures where they are found.

Weldon has traveled to some of the world’s major gem sites, including Burma, India, East and South Africa, Colombia, Bolivia, Brazil, Russia, and several other gem sources. His photographs are published in scores of international gemological, jewelry and consumer publications, illustrating his own and other authors’ articles, and in several books. They have also appeared regularly on the cover Gems & Gemology since 2008.
Every one of Weldon’s photos has a story to tell  — whether it is how he conceived the image, how he chose to show the gem at its best, or how he decided to show the context of the locality where the gem was found. Over the course of three decades, he has photographed some of the world’s most important gems and jewelry.
He combines art and gemology in a way that makes us even more appreciative of what we see.
“The industry that we are all a part of and love so much is very much a visual one. Everything really relies on our senses, but particularly our eyes and what we see and feel,” he says. “On the basis of a good image we often make decisions in an instant that transfer millions of dollars across the world.”
Here are some of his favorite gem stories.
Don’t Make a Habit of This

The historic Munsteiner aquamarine carving Dom Pedro was donated to the Smithsonian Institution by Jane Mitchell and Jeffery Bland and is housed in the National Museum of Natural History's Janet Annenberg Hooker Hall of Geology. Photo by Robert Weldon
Weldon was given the opportunity to photograph the 10,363 carat (ct) Dom Pedro Aquamarine, a 14-inch tall obelisk carved by master gem sculptor Berndt Munsteiner, at a Tucson show more than 20 years ago.
Unable to fit it into his small portable studio, he and gem dealer Evan Caplan decided to take it out to the desert. They placed it carefully on a rock with the iconic Mission San Xavier del Bac serving as the backdrop. The ancient mission, constructed between 1783 and 1797, juxtaposed against this modern, angular gem sculpture, created a dramatic image.
“Evan crouched inches away, ready to dive for it — and save it — as it swayed slightly in the breeze,” Weldon recalls. They got the shot and spirited the sculpture to safety in Caplan’s booth.
Months later, Munsteiner marched towards Robert, who was “transfixed, mortified and scared” as the legendary carver approached him.
Then he beamed. “Robert, that was a great picture,” he said. After a pause, he added: “By the way Robert, do you know what the value of this stone is?”
Luckily, the photo was a success and was featured in JCK magazine; Munsteiner says a copy hangs in his living room.
“This is something you should never do! It is much too dangerous and too much of a risk,” Weldon says. “Never, never would I do that again.”
The Dom Pedro is “the largest single piece of cut-gem aquamarine” according to the Smithsonian Institute, where it has been on display since 2012. It so breathtaking that the Smithsonian said it is “one of the few objects in the world that can hold its own in a display case just 30 feet from the Hope Diamond.”
A Stunning Stalactite

“Atlantis” Star of the Congo Mine Lubumbashie, Haute-Katanga Democratic Republic of the Congo Approximately 31.75 kg and measures 70 cm in length, by 25 cm in width.   This magnificent specimen of malachite and chrysocolla is from an area in the southern part of the Democratic Republic of the Congo known as the “copper crescent,”  an area famous for its copper mines.    Broken chrysocolla-coated stalactites reveal malachite cores. Look closely; often there is a small hole in the center. These are tubes through which solutions dripped and caused the downward growth of the stalactite. Where these straw-like openings don’t exist, solutions ran down the outside of the stalactite, making them thicker.   Some of the stalactites are oddly curved and bulbous. When stalactites develop they are under the influence of gravity and should form straight growth. The curvature suggests an outside influence like air or water currents caused more growth on one side. All in all, this amazing specimen is reminiscent of a dreamy underwater scene or fantasy world leading to its name, Atlantis. Photo: Robert Weldon
This malachite and chrysocolla specimen, found in a cave in the Congo, weighs 80-90 pounds and is a meter and a half in length.
“Interestingly, it is on display upside down. But we didn’t want to photograph it [or display it] the way it formed in nature, because such positioning would break those beautiful stalactites,” Weldon says.
The GIA Museum acquired this “stunning” malachite and chrysocolla specimen at the 2020 Tucson shows. It has been nicknamed “Atlantis” for its resemblance to the exotic underwater realm. See a video presentation and explanation of its formation.
If you look closely, you may see a small hole in the center of each stalactite. Solutions dripped though these straw-like tubes and caused the downward growth of the stalactite. If a tube opening was not there, the solutions ran down the outside of the stalactite, making them thicker.
Stalactites normally develop under the influence of gravity and should form straight growth. Some of the stalactites in this specimen are oddly curved and bulbous, which suggests an outside influence such as air or water currents that caused more growth on one side.
“You really begin to understand the formation of gemstones just by looking at this. You can see how drip by drip mineral-rich waters gave rise to those colorful stalactites and this is what you see today,” Weldon says. “It is a spectacular display of how only nature can be as gaudy as this. Wow, what a piece — it’s just absolutely stunning.”
Watch a GIA Knowledge Session where Director of the RTL Gemological Library Robert Weldon, Senior Manager of Research Dr. Aaron Palke, and Supervisor of Field Gemology Wim Vertriest offer an exclusive look at GIA field gemology expeditions through previously unpublished photographs. @chapter:33 @chapter:2 @chapter:33


# Publication Year: 2015
# Title: Tsavorite Garnet and Mahenge Red Spinel
# Abstract: Figure 1. Daniel and Andre Assaf of the Tsavorite Factory explained the current market for tsavorite. Photo by Duncan Pay/GIA.

At GJX, Daniel Assaf (The Tsavorite Factory, New York City; figure 1) explained the current market situation for tsavorite garnet, Tanzanian red to pink spinel, and yellow danburite. According to Assaf, the recent recession and the ensuing disruption in supply had less of an impact on his business than increasing demand from China. For him, current rough scarcity and high prices relate more to the growth in the Chinese jewelry market, which 5 to 10 years ago was a fraction of its size today.

Assaf explained that both tsavorite and spinel are rare stones, and even minor changes in the market might have a considerable impact. If just a fraction of one percent of Chinese consumers becomes interested in tsavorite, this has a measurable consequence for supply, especially if production in mining areas is static or even showing slight declines. According to Assaf, the biggest tsavorite purchasers at the source in Arusha, Tanzania, are Sri Lankans buying for the Chinese domestic market. These buyers are prepared to pay very high prices for tsavorite rough.

	The Tsavorite Factory

Daniel Assaf of the Tsavorite Factory provided a detailed market update for tsavorite garnet. In this interview, he explains how unprecedented Asian demand for this rare gem has drastically affected availability and pricing for his customers.
To illustrate the sporadic nature of current supply, Assaf cited a bright, light-toned green grossular garnet. This material has become popular and is sold as “Merelani mint” garnet. It is usually recovered as a byproduct of tanzanite mining. Every so often, he related, miners find a productive pocket and buyers fly in within a couple of weeks.

According to Assaf, the stones on the tray in front of us (figure 2) were from the latest small pocket and had been in the ground just a few months earlier. After the initial flurry of buying activity, Assaf said, it might be another year or two before a similar discovery. In the meantime, the miners might bring buyers the occasional stone—at much higher prices.

Figure 2. These light-toned Tanzanian grossular garnets—termed “Merelani mint”—were mined just a few months prior to the Tucson show. Photo by Duncan Pay/GIA; courtesy of
Tsavorite Factory.
In Assaf’s opinion, today’s tsavorite rough prices in Arusha are almost “out of control.” In effect, there is a disconnect between the Arusha prices and the prices in Tucson, which will likely take several years to readjust.

His company stops buying before the Tucson show because the clientele here will not pay the high asking prices. He cited an instance several weeks earlier in which buyers were offering him top-quality rough for approximately $10,000 per stone, in sizes sufficient to cut 3 ct finished gems. A stone cut from this rough would have a per-carat price well above what the market at the Tucson show would pay. Besides the high asking price, Assaf said there is a significant element of risk in buying rough: “You never know what kind of unpleasant surprises you might find.”

He pointed out that there are places in the world where such high prices are accepted—China and possibly parts of Europe—which is why the few fine rough tsavorites that become available every month are snatched up. Assaf had just heard of a 7-gram piece of tsavorite—perhaps suitable for a 10 ct finished gem—that sold for $200,000 in Arusha.

Assaf showed us two examples of the finest tsavorite colors. In his opinion, both are of equal merit (figure 3, left). Some clients love the deeper, darker color, while others prefer a brighter, lighter-toned green. In either case, he said, the most important consideration is to have a blue color component rather than a yellow one. As long as the gem is not overly dark, and has a bluish cast to the green, it is a quality stone. If it is pale but still has a bluish component to the green, he would classify it as a “mint” garnet.

Figure 3. Left: Some prefer tsavorite garnets with a brighter color, while others prefer a darker appearance. The stone on the left weighs 9.50 ct. Right: This suite of three pear-shaped tsavorites totals 37.79 carats. The approximate asking price for such fine gems would be about $15,000 per carat. Photos by Duncan Pay/GIA; courtesy of Tsavorite Factory.
We asked Assaf how recent Chinese demand has affected tsavorite prices. He said that for sizes under 2 ct, prices have increased as much as 30–40%. The impact has been most dramatic in larger stones: For gems larger than 3 ct, prices have tripled. He felt that prices for large tsavorites have gone up in relation to emerald and other gems due to scarcity of supply and high demand.

To emphasize the point, Assaf chose a suite of three tsavorite pear shapes totaling 37.79 carats (figure 3, right). Each gem was above 10 ct and of the highest clarity, so they constituted exceptionally rare material. Aside from these standouts, Assaf admitted he had few stones of such size—large stones are typically a Tsavorite Factory specialty—due to the prohibitively high price of rough. He lamented that with today’s stratospheric prices, he would have to pay around $200,000 to obtain another 7-gram piece to cut another 10 ct gem. And very few clients—likely none at this show—would accept the resultant high per-carat prices for the finished gem. That leaves two possibilities: Either the prices will adjust in Arusha, or they will become accepted in the U.S.

Assaf recounted that some of the same market factors apply to red spinel. His company does not carry spinel from Myanmar, focusing instead on Tanzanian material. This year, he said, a specific color people were calling “Mahenge”—deep pink with a touch of orange, almost like a “padparadscha” color—was in extremely high demand (figure 4). Assaf had sold all of his “Mahenge” spinel but none of the other colors. While these lavenders, blues, and mauves are quite beautiful and competitively priced at around 10% of the pinks, the red to pink spinels are what his clients seek. Assaf also mentioned that buyers looking for something unusual picked yellow danburite from Tanzania, and that this gem had sold quite well for him at the show (Summer 2008 GNI, pp. 169–171).

Figure 4. An example of “Mahenge” spinel from Tanzania. This was one of the few examples left at Daniel Assaf’s booth at the time of our interview. Photo by Duncan Pay/GIA; courtesy of Tsavorite Factory. @chapter:33 @chapter:2 @chapter:33


# Publication Year: 2022
# Title: Aegirine in Poudretteite
# Abstract: Figure 1. An aegirine crystal inclusion in poudretteite rough from Mogok, viewed with oblique fiber-optic illumination. Photomicrograph by Kyaw Thu; field of view 2.3 mm.
Originally discovered in Canada in the 1960s and named for the family that owned the rock quarry where it was found, extremely rare poudretteite was recognized as a new mineral in 1986. In 2000, the first gem-quality stone was discovered in Mogok, Myanmar. Recently, local miners found a new poudretteite deposit near Pein-Pyit village in the northeastern part of Mogok town. Some of these mined poudretteite gemstones contained unusual green crystal inclusions (figure 1).

Figure 2. Aegirine inclusion showing sprays of acicular crystals in poudretteite rough from Mogok (darkfield and oblique fiber-optic illumination). Photomicrograph by Kyaw Thu; field of view 0.84 mm.
The author examined two rough gem-quality light pink stones weighing about 1.065 and 1.104 ct. Gemological observation and Raman analysis confirmed that the two samples were poudretteite. The green crystal inclusions were present as both single crystals and sprays of acicular crystals in a radial pattern (figure 2). They had a mostly prismatic crystal shape with a bright yellowish green color. Micro-Raman analysis identified them as aegirine, the first discovery of this mineral in poudretteite from Mogok. Aegirine commonly occurs in alkaline igneous rocks, nepheline syenites, carbonatites, and pegmatites. This mineral inclusion could be an indicator of Mogok origin. @chapter:12 @chapter:0 @chapter:12


# Publication Year: -
# Title: Gemstone ‘Paintings’ Tell Story of a Master Craftsman, Gem and Jewelry Mentor
# Abstract: Visiting the display window at M.D. Hohenstine Jewelers was a beloved tradition for generations of Columbus, Ohio residents and tourists. When Hohenstine installed his 2,000th display, the mayor declared it M.D. Hohenstine Day in the city. Photo by M.D. Hohenstine/Courtesy of Judith Allen Hall

“For the first Christmas in 50 years, there is no intricate, shimmering picture woven of hundreds of gemstones to decorate the holiday display window of the jewelry store at 37 S. High Street on the ground floor of the Neil House. A tradition that gave a unique flavor to Capitol Square and warmed the hearts of generations of Columbus visitors and shoppers since 1927 has ended with the death of the artisan who painstakingly handcrafted gem paintings for all seasons.” – Columbus Citizen-Journal, 1976 obituary of M.D. Hohenstine

Aside from a few mementos available for sale on Etsy and eBay – a vintage rose gold brooch, a sterling silver spoon, a taxidermy butterfly serving tray – along with a handful of business directory listings and an obituary in the local newspaper, there isn’t much of an online record that tells the story of jeweler M.D. Hohenstine and his Columbus, Ohio retail store.

And yet, Hohenstine’s spectacular window displays, featuring elaborate, artistic arrangements of hundreds of loose gemstones, were a creative and logistical marvel that captured the imagination of Ohio’s capital city for decades.

“People traveled to Columbus from all over and made a point of going to see ‘the window,’” remembers former employee and longtime family friend Judith Allen Hall. “During the Christmas season, people would sometimes line up three and four deep, trying to look in. Over the years, so many feet stood in front of Hohenstine’s store window that the pavement in front of it had to be repaired because of depressions in the concrete.”

M.D. Hohenstine Jewelers’ location on High Street, across from the capitol building in the heart of vibrant downtown Columbus, Ohio, meant that employees had a front-row seat for several important occasions in history for 50 years. Here, a World War II victory parade and United States Army Band performance passes in front of Hohenstine’s store, seen at the far right of the photo. The clock in front of the store was also marked with his name. In 2012, the M.D. Hohenstine clock was refurbished and returned to the store’s first location, at 21 East Gay Street. Photo by the United States Army Signal Corps
M.D. Hohenstine Jewelers sat in the heart of one of the city’s most bustling neighborhoods, where visitors toured, entertainers performed, and politicians and military personnel were welcomed with parades and fanfare. Its location in the historic Neil House hotel – across from the state capitol building, down the street from the iconic Lazarus department store and the city’s theater district – along with its dramatic curved windows and rich, oversized mahogany display cases, drew actors, big-band and jazz musicians, and entertainers, including the apex of jewelry-loving celebrities, Elizabeth Taylor.

“I’m sure whatever design was in the window was what drew her in that day,” says Hall, who notes that “Mr. H,” as employees called him, stayed in the back of the store and let staff have face time with the A-lister as she browsed the counters.

Family members, like Hohenstine’s grandchildren, still look back fondly on their visits to 37 S. High Street. “My favorite memories always included seeing his gemstone displays in the store window,” says Hohenstine’s granddaughter, Tracy Hagen-Smith.

As much as Hohenstine’s intricate displays – all 2,000-plus of them, catalogued diligently in 35-mm slide photographs – drew public attention, he also quietly built a circle of inspiration and influence within the gem and jewelry industry. Hohenstine’s behind-the-scenes mentorship and willingness to pass on his extensive knowledge of gemology, bench jewelry and the logistics of business operations, has continued through generations of GIA-educated jewelers and gemologists long after the doors of his business closed.

View Gallery

‘Tuesdays Were Display Days’
Gems & Gemology featured Hohenstine’s 1,039th design on its cover in 1951, and noted his “effective window displays,” which started with his collection of hundreds of loose, natural gemstones.

“None were synthetic,” Halls says, “and none were for sale.”

Hohenstine kept the gems he used for his displays in the left drawer of his custom-designed desk, wrapped in papers scrawled with notes like “56 rubies” or “one 10-ct diamond.” He used a soft pencil to sketch designs, often celebrating a season, holiday, local sports team or charity organization, and meticulously arranged the gems over them. Each slide was marked with a number in one corner, and the gems’ identification in the other. The process took at least six hours, and customers walking by could look into Hohenstine’s secure diamond room and watch the craftsman at work.

The gemstone arrangements – unsecured in any way to the plates – were then photographed and carefully carried 100 feet from the diamond room to the window for dressing.

M.D. Hohenstine’s 1,777th gemstone design, seen here both in the window display and close-up, was one of many patriotic designs he created. Right photo by M.D. Hohenstine. Both photos courtesy of Judith Allen Hall
“Tuesdays were display days,” says Hall, who remembers many of the details of how Hohenstine created his window displays. “Every other Tuesday evening, from 1927 until his death in 1976, he trimmed the windows, and a new gem design went in the center of the left window facing the capitol – even on the Hohenstines’ 50th wedding anniversary!”

The slide photographs weren’t simply for posterity. Hohenstine used them as an educational tool for his frequent lectures to gem and mineral societies, as well as civic organizations, such as the Kiwanis Club, for several decades.

M.D. Hohenstine, right, is pictured with son-in-law Stewart Cox at a gem and jewelry lecture to the Euclid, Ohio Kiwanis Club in 1974. Hohenstine, who shared slide photographs of his gem displays to many of his lecture groups as an educational tool, was a believer in gemological and continuing education for everyone. “He was even ahead of his time in supporting a college education for each of his four daughters,” says granddaughter Tracy Hagen-Smith. Photo courtesy of Tracy Hagen-Smith
A Mentor in Jewelry, and Advocate for GIA Education
Hohenstine was born in 1891 and grew up in a relatively poor family in Columbus’ German Village neighborhood; after finishing eighth grade, he helped earn money for the family by working for well-known jeweler and watchmaker Edwin S. Albaugh. Hohenstine married Albaugh’s niece, Margaret Vause, and eventually opened his own small jewelry store in downtown Columbus. Business became so robust that he moved his store to the larger Neil House location in 1927, where it continued to thrive in a competitive area.

He helped differentiate himself early on. “When he learned about GIA courses, which were by mail at the time, he promptly signed up and became an early Certified Gemologist [today’s GIA GG],” Hall says. “He was so proud of that.”

Hohenstine hired Hall’s father, Lawrence Allen, who had also apprenticed under Albaugh and well-known local jeweler, Curly Miller, in 1935. Hohenstine became a friend and mentor to Allen over the next five years, as Allen also began to earn his Certified Gemologist diploma from GIA. Allen left to open his own store, Allen Jewelers, in nearby Mount Vernon, and become vice president of the Ohio Jewelers Association, but the two stayed in touch.

Hall visited Hohenstine’s store with her father as a toddler, and at 12 years old, began to work alongside him at Allen Jewelers in 1948. “I sat next to him every day at the bench,” says Hall, until she started high school.

Lawrence “Larry” Allen, friend and employee of M.D. Hohenstine and father of Judith Hall, became a jeweler who, according to Hall, “could do anything.” Allen was an early student in GIA’s Distance Education courses, and received a glowing, handwritten review on his first exam. “Congratulations – an excellent paper!” wrote GIA’s Bob Crowningshield. “I trust you can complete all courses with a fine record.” Photo courtesy of Judith Allen Hall
Tragedy struck the Allen family shortly after Hall’s graduation in 1954, when her father passed away unexpectedly at 41. Hall, only 19 years old, took the reins of the family store and managed it for a few years until their landlord sold the building and the family shuttered Allen Jewelers permanently.

Hall and her sisters – all trained in the trade – moved to Columbus and joined different jewelry stores. Her father’s old friend M.D. Hohenstine welcomed Hall to his business with open arms. He proudly displayed her Registered Jeweler certificate from the American Gem Society, which she had earned while running the family store, on the wall of M.D. Hohenstine Jewelers – right alongside his own. This was notable, Hall says, as women’s roles as professionals in the gem and jewelry industry were not yet fully accepted in some circles.

She worked alongside Hohenstine for eight years, handling sales, assisting in his window display dressings, and eventually with his encouragement, dipping into the world of gem education. Hall lectured and gave presentations on behalf of M.D. Hohenstine Jewelers until the store was bought in 1966 by fellow jeweler Thomas Hawk. Hohenstine continued to work there, still creating his biweekly gem displays, as Hall moved on to Florida, to teach gemology at multiple schools, including the University of South Florida in Tampa.

Judith Allen Hall, who worked in retail jewelry stores owned by her father, Lawrence Allen, and mentor, M.D. Hohenstine, before embarking on a 30-year career in gemology education, hopes her donation to GIA can help preserve the legacy of jewelers and artists from the past. “There are so many people in the industry who have stories that don’t get told,” she says. “So much of that history could be lost.” Photo courtesy of Judith Allen Hall
A Legacy of Sharing Knowledge
Hall, who took gemology and design classes at GIA through the years, launched into teaching and reached out to her mentor in 1974 with a letter requesting copies of the window design slides.

“At first I asked him because I was trying to fill up 30 hours of class time,” she laughs.

Hohenstine wrote back that he would not send her copies, but originals – though he had previously refused every other request for them from others.

“I am sending 40 slides from my collection as a gift,” he wrote, “with the understanding they are to be used for educational purposes.”

From that point on, Hall never taught a class without them.

“People were always excited to see them,” she says, “and fascinated that someone would have that big of a collection that was not for sale.”

Jeweler M.D. Hohenstine had many creative pursuits outside of jewelry and gemology. “I think of him as always doing, rather than talking,” says his granddaughter, Tracy Hagen-Smith. “His craftsmanship and artistic skills were extensive. He was involved in photography, clock-making, and had his own theater in the basement of his home. I still have two pieces of marquetry that he made in my home.” Here, he plays the organ as his wife, Margaret – “always his biggest fan,” says Hagen-Smith – looks on. Photo courtesy of Judith Allen Hall
Over the next few decades, Hall encouraged her students – many working jewelers and pawnbrokers – to continue their studies at GIA. In a profession like pawn brokerage, she explains, professionals have to make decisions quickly, with nothing more than a loupe in hand and gemological knowledge in their heads.

“I convinced many of them to take GIA classes,” Hall says. “I explained that having that foundation of GIA knowledge is what allowed me to identify gemstones quickly in the first place.”

One of those students, Shane Socash, was a working jeweler looking to expand his gemological knowledge.

“Judith exposed me to the history, lore and beauty of gemstones that I wasn’t getting in other parts of my jewelry education,” says Socash, who went on to earn his Graduate Gemologist diploma and become the owner of David Reynolds Jewelry & Coin in St. Petersburg, Florida. “It allowed me to broaden my knowledge, and I knew since she studied at GIA, that I wanted to explore that direction in my life, too.”

Shane Socash, GG, and owner of David Reynolds Jewelry & Coin, is part of the circle of influence surrounding M.D. Hohenstine, who mentored Socash’s gemology instructor, Judith Hall. As a young jeweler, Socash determined that he wanted to attend GIA like she did, and one day found $400 in the parking lot of a jewelry store. He returned the cash to the owner of the store, but the owner said it wasn’t his and suggested that Socash keep the money if no one claimed it. Socash decided its best use was to put the money toward his first Distance Education course at GIA. Photo courtesy of Shane Socash
When Hall retired from teaching in 2016 at 80 years old, she began to think about the best home for Hohenstine’s slides, including those sent to her by Hawk upon Hohenstine’s passing, and the first edition of Richard T. Liddicoat’s “Gem Identification” book that he gave her.

“In the process of deciding where the best permanent home for them would be, I concluded that GIA is the connecting thread that links us together,” she says. “It’s the vehicle through which and by which we not only receive education, but we also can use to pass on our passion and knowledge of gems and jewelry industry history.”

Hall inquired whether GIA’s Richard T. Liddicoat Gemological Library and Information Center would be interested in a donation to further gemological education. She was “thrilled” when librarians said they would be honored to safeguard the slide collection that Hohenstine had entrusted to her so many years ago.

“For me, that connecting thread was that Mr. Hohenstine, who was an early GIA graduate, taught my father, who also became a GIA graduate,” she says. “My father inspired me to study at GIA, and as a recipient of two generations of jewelry industry education and knowledge, I taught for 30 years and was able to inspire graduates like Shane Socash, who passes on his knowledge to his clients, and even his daughters.”

It’s been just shy of a century since M.D. Hohenstine installed the first of his “handcrafted gem paintings,” and 40 years since he created his last. But because he invested in the next generation of the gem and jewelry industry, his legacy of knowledge, craftsmanship and creative excellence will continue to inspire jewelers in the years ahead – far beyond the borders of the town where he created such unique and memorable art. @chapter:25 @chapter:2 @chapter:25


# Publication Year: 2019
# Title: Laboratory-Grown Sapphire with Unusual Features
# Abstract: Figure 1. This 14.36 ct pink-orange synthetic sapphire contains large fractures with orange staining and some partially crystallized foreign material. Photomicrograph by Moqing Lin; field of view 15.26 mm.

The Hong Kong laboratory recently examined a 14.36 ct pink-orange cushion mixed-cut specimen measuring 12.97 × 11.41 × 10.59 mm. Standard gemological testing yielded an RI of 1.760–1.768, a chromium emission line in red using a handheld spectroscope, strong red fluorescence under long-wave UV, and weak red fluorescence under short-wave UV. These properties were consistent with pink sapphire. Magnification revealed large fractures containing orange staining and some partially crystallized foreign material (figure 1). The foreign material partially crystallized in a dendritic pattern resembling that of diaspore (figure 2). Other natural-looking features included a twinning plane and tubules. Nonetheless, the observation of indistinct Plato lines and a slight curvature in the twinning plane raised suspicion about the stone’s nature.

Figure 2. The foreign material partially crystallized in a dendritic pattern in the fractures, reminiscent of diaspore. Photomicrograph by Moqing Lin; field of view 7.64 mm.

Figure 3. The pink-orange specimen showed a strong red curved band in the DiamondView, confirming its identity as a flame-fusion synthetic sapphire. Image by Moqing Lin.
A strong red curved band observed in the DiamondView confirmed it was a Verneuil (flame-fusion) synthetic sapphire (figure 3). The absence of Ga, V, and Fe in the specimen, determined using laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS), provided further evidence supporting its synthetic nature. Ti was below detection limit in all six spots. Cr was below the detection limit in one spot and 37.61–44.31 ppma in five other spots.
Although flame-fusion synthetic sapphires are common in the marketplace, it is unusual to encounter a specimen containing such natural-looking orange staining and partially crystallized foreign material in the fractures. Careful observation as well as advanced testing are required for the correct identification of the natural or synthetic origin of such specimens. @chapter:19 @chapter:0 @chapter:19


# Publication Year: 2018
# Title: Designs from Erica Courtney
# Abstract: Figure 1. Left: Erica Courtney’s Victoria pendant showcases a 114.56 ct colorless topaz with a 2.76 ct Mahenge spinel set above it, surrounded by 86 Mahenge spinels, 20 rubellites, 10 Mandarin garnets, and 558 diamonds. Right: The Autumn pendant contains a 47.16 ct Malaya zircon accented with 3.91 carats of Tanzanian peach spinel, 7.00 carats of peach topaz, 1.31 carats of yellow sapphire, and 1.68 carats of diamond. Photos by Kevin Schumacher.
Erica Courtney has been adorning Hollywood stars for the red carpet for decades. Her eye for color and bringing out a stone’s beauty are immediately apparent. In talking to her at the AGTA show, we discovered that she is the only jeweler in her family. She was introduced to jewelry making at the age of 11 through a Catholic Youth Organization class. This multiple AGTA Spectrum Award winner has always done things her own way, not following trends when choosing stones or creating designs. In fact, she confided that she does not plan what stones she will purchase, but lets the gems pick her. She likened the jewelry design process to a movie going through her head—designs start forming and keep changing until she settles on the final one.

A Closer Look at Erica CourtneyErica Courtney discusses her entry into the jewelry business and her design philosophy, and displays several notable pieces.
Courtney’s work pulls the viewer in to study meticulous details—the more you look, the more you see. Her attention to detail does not stop at the outward-facing front of her pieces. You need to turn the pieces around in all directions to appreciate the designs that spill over the edges and cover the sides and backs of her work. Returning to her point about the gems picking her, she stated that once a gem seduces you, “if you buy for love, you can’t make a mistake.” This is evident in the centerpiece stones in four of her creations. The Victoria pendant (figure 1, left) contains a 114.56 ct colorless topaz accented with a Tanzanian spinel from Mahenge and surrounded by more spinel plus rubellite, Mandarin garnets, and diamonds in an intricate gallery work. In the Autumn pendant (figure 1, right), a 47.16 ct Malaya zircon is surrounded by Tanzanian peach spinel, topaz, yellow sapphire, and diamonds. The Etoile ring’s green African Paraíba-type tourmaline is flanked by blue Brazilian Paraíba tourmalines and diamonds (figure 2, left), while the Imperial earrings (figure 2, right) contain perfectly color-matched Mandarin garnets flanked by pink spinel and diamonds. She confided that the electric orange and pink in the Imperial earrings was her favorite color combination of these four pieces.

Figure 2. Left: Courtney’s Etoile ring has a 7.71 ct Paraíba-type tourmaline accented with 12 Paraíba tourmalines and 370 diamonds, all set in 18K yellow gold. Right: The Imperial earrings feature a pair of Mandarin garnets (21.25 total carat weight) accented with 1.87 carats of pink spinel and 0.71 carats of diamond in 18K yellow gold. Photos by Kevin Schumacher.
Courtney’s desire to understand the entire gem cycle from unmined rough to polished stones set in finished jewelry has taken her backpacking across far-flung locations. She described the experience as giving her an appreciation of how difficult it is to find real gems. She also took notice of the passion of the miners, each wanting to be “the one to have found it.” @chapter:20 @chapter:2 @chapter:20


# Publication Year: -
# Title: Fall 2009 G&G Book Reviews
# Abstract: “Famous Diamonds, 5th Ed.”
By Ian Balfour, 335 pp., illus., publ. by Antique Collectors’ Club [www.antique-acc.com], Woodbridge, Suffolk, UK, 2009. $95.00

	“Cameos: Old & New, 4th Ed.”
By Anna M. Miller, edited by Diana Jarrett, 382 pp., illus., publ. by Gemstone Press [www.gemstonepress.com], Woodstock, VT, 2009. $19.99

	“Sapphire Mining in Madagascar”
Contributions to Gemology No. 8, 46 mins., released by GRS Gemresearch Swisslab [www.gemresearch.ch], Lucerne, Switzerland, 2009. $40.00

“Profiting by Design: A Jewelry Maker’s Guide to Business Success”
By Marlene Richey, 135 pp., illus., publ. by MJSA Press [www.mjsa.org], Providence, RI, 2008, $34.95

“Cristalli: L’Ordine dal Caos [Crystals: Order from Chaos]”
By Adalberto Giazotto, Federico Pezzotta, and Giovanni Pratesi, 240 pp., illus., publ. by Giunti Editore [www.giunti.it], Florence, Italy, 2008 [in Italian], 48.00

“Gill’s Historical Index”
By Joseph O. Gill, 647 pp., illus., publ. by the author [www.archive.org, search for “Joseph Gill”], 2009, Free

To view the full section, download the PDF above.

	DATA DEPOSITORY

Famous Diamonds, 5th edition - Additional Material
	Fall, 2009 @chapter:33 @chapter:2 @chapter:33


# Publication Year: 2020
# Title: Fluorophlogopite in Burmese Spinel
# Abstract: Figure 1. This crystal broke the surface of a dark red spinel believed to be from Mogok. It had a lower luster than the spinel, and undercutting indicated a lower hardness. Photomicrograph by Richard W. Hughes, diffuse overhead illumination; field of view 2.5 mm.

Lotus Gemology in Bangkok received a large parcel of dark red spinels for identification. Their colors, inclusion features, and trace element chemistry suggested that they originated from Myanmar’s Mogok Stone Tract.

Figure 2. In darkfield illumination, cleavage was visible inside the crystal. Micro-Raman analysis showed it to be fluorophlogopite. Photomicrograph by Richard W. Hughes, darkfield illumination; field of view 2.5 mm.
In one faceted specimen, a crystal was found breaking the surface (figure 1). The crystal’s surface luster suggested a refractive index below that of the host spinel, and undercutting suggested it was also significantly lower in hardness. The inclusion’s interior also displayed signs of cleavage (figure 2). Thinking it was possibly a carbonate, we proceeded to do micro-Raman analysis on the crystal. To our surprise, the result was fluorophlogopite.
Fluorophlogopite, KMg3(AlSi3O10)(F,OH)2, is a species in the mica group and a member of the trioctahedral mica subgroup. To the best of our knowledge, this is the first reported instance of this species in spinel. Nor are we aware of it having been found included in any gem mineral to date. @chapter:12 @chapter:0 @chapter:12


# Publication Year: 2014
# Title: Books: Smithsonian Nature Guide on Gems
# Abstract: By Ronald Louis Bonewitz, 224 pp., illus., DK Publishing, New York, 2013. $14.95.

              As part of the Smithsonian Nature Guide series, Gems has the look and feel of a field guide or a lab manual. The book is durable enough to serve these purposes, and the technical information contained within lends itself to such use on a limited basis. Although licensed by the Smithsonian Institution and featuring some images from its collection, this book is largely a British product, using terms that are more common among gemologists from the United Kingdom and Europe.

The 34-page introduction serves as an overview of gemology, including such topics as gem formation, classification, cutting, enhancements, synthetics, and history and folklore. The book’s only other section, “Gemstones,” includes segments on precious metals and organics and a glossary, but the largest entry is “Cut Stones.” Here, the various gems are arranged much in the style of a mineralogical text, divided by chemical composition. Sections cover the native elements, sulfides, silicates, and tungstates; based on that system, the cut gems are sometimes are presented out of the order anticipated by someone with a working knowledge of Dana’s System of Mineralogy and Dana’s Textbook of Mineralogy. It should also be noted that the book does not further divide the silicates into categories such as soro-silicates or tekto-silicates. For each featured cut gem, precious metal, and organic gem, there is a profile box detailing its basic properties and, where appropriate, the typical cutting styles. The basic chemical formula is given, along with the name origin, formation and source information, and color images, including examples of rough material.

One of the book’s merits is ease of use, with its portable format and easily located vital information. It contains far more gem materials than most comparable books, opening up a whole new world of gems to the consumer. Another virtue is the profusion of color images used to illustrate various aspects of the gemstones. I applaud the “Gem Enhancement” section: To make an informed purchase, the consumer needs to be aware of methods to improve the appearance, durability, and value of a gem material.

Some areas could use revision. The reader is given no sense of the author’s qualifications to write about gemstones. Another issue concerns the use of the outdated terms “precious” and “semi-precious.” Why should the negative connotation of “semi-precious” be applied to such wonderful gems as alexandrite or red spinel, which often sell for at least as much as those traditionally labeled “precious?” I was surprised that beryl, rather than topaz, was used to illustrate a hardness of 8 on the Mohs scale, and disagreed with the assertion that soft stones are cut only for collectors. This may have been true in the past, but with the recent boom in at-home shopping, softer stones such as fluorite are being purchased by a great many consumers. It is important to inform consumers of the care required for softer gems without chasing them away. The color images, while numerous, do not always convey the actual color of the gem. In many of the photos, lines are used to point out a particular aspect of the gem, such as fire or doubling, yet in some instances you can’t see that feature.

Finally, I found some faulty information. The most conspicuous inaccuracy is the statement that flux-melt gemstones, including some synthetic emeralds, leave curved growth zones. The reality is that curved growth zones are mostly associated with flame-fusion synthetics, which do not include synthetic emerald. Flux-melt synthetic emeralds are known for showing angular growth features. There are other inaccuracies of various degrees that could be addressed, but I do not wish to create too negative an impression.

Despite some outmoded terminology and factual errors, this attractive book’s numerous gemstones, helpful illustrations, portability, and low price make it worth purchasing, especially for the general consumer. @chapter:5 @chapter:0 @chapter:5


# Publication Year: 2017
# Title: New Emerald Production from Belmont
# Abstract: Second-generation stones from Brazil’s Canaan mine are often cleaner and lighter in color than those from the first geological event. Photo by Eric Welch/GIA.

	The Belmont mine in Brazil has been a key emerald supplier in the global market for the past 40 years. It is one of the very few companies that can guarantee a complete mine-to-market chain of custody for the emeralds it produces. As open-pit mining became more expensive over the past decade, underground mining gradually generated a larger share of production at Belmont. Today, all mining activity at the original open pit is underground. Open-pit mining will continue in the two pits to the north of the original site. General manager Marcelo Ribeiro revealed some exciting news about the Canaan mine, about 2 km away from the original pit, and expansion plans for the sorting and cutting facilities.

	Belmont acquired interest in the Canaan mine through a partnership with its original owners. Exploration and underground mining infrastructure are still ongoing at this site. Although the operation just started about a year ago, Ribeiro and his team have learned a lot about this deposit through field studies and chemical analysis. The interesting finding is that there is plenty of beryllium in this area, which makes the survey of chromium concentration critical to locating the mining targets. This is the exact opposite of the situation at the original Belmont site, where beryllium is the critical factor.

	According to Ribeiro, two geological events were responsible for emerald crystallization in the area. The original Belmont mine is mainly influenced by the first event, Canaan by the second. Based on research, the second event was much stronger at the Canaan mine, destroying most of the crystals formed during the first event. The second-generation emeralds have a lower chromium concentration, and therefore lighter green colors, but they are often larger and cleaner than those from the Belmont mine (see above). The new production is sometimes slightly yellowish or bluish. Ribeiro is very excited about the Canaan production, which allows the company to provide a greater selection to its clientele.

	Belmont currently cuts 50% of the Canaan production by value. All medium- to high-quality stones are cut on-site to add more value. To increase the capacity of the operation and make mining cheaper for long-term sustainability, the company plans to add two more optical sorters and further expand the cutting facility. Belmont will also keep promoting its mine-to-market product and better communicate with younger buyers to make them feel proud of their emerald purchases. @chapter:2 @chapter:0 @chapter:2


# Publication Year: 2017
# Title: Flashes and Flames inEthiopian Opal
# Abstract: Figure 1. This 2.68 ct opal displayed play-of-color when viewed face-up (left) and flame-like chatoyancy on its slightly domed base (right). A more pronounced dome might have had the effect of sharpening the sheen into a cat’s eye. Photos by Kevin Schumacher.

	The relatively new source for precious opal located in Ethiopia’s Wollo Province produces material with vibrant play-of-color and occasionally with interesting inclusions. A recently examined 2.68 ct cabochon contained a scattering of octahedral metal sulfide inclusions (relatively common in Ethiopian opal) along with an unusual combination of optical phenomena: play-of-color and chatoyancy. Face-up, the stone showed the typical flashes of colors one would expect in precious opal (figure 1, left). However, the back of this cabochon contained an interesting structure that produced a sheen-like chatoyancy over its slightly rounded surface (figure 1, right). This chatoyant zone was strikingly similar to the flame structure seen in some non-nacreous pearls, which is produced by an intricate structure of aragonite crystal laths (figure 2). In the case of this opal, the flame-like structure’s cause remains an enigma, though it could be due to the structural influence of a preexisting fibrous mineral replaced by opal. Unfortunately, Raman analysis was unable to detect any presence of another mineral phase in the chatoyant area, so the exact cause of chatoyancy is still unknown.

	Figure 2. The fibrous nature of the opal’s unusual chatoyant zone is clearly revealed, along with the numerous minute octahedral black metal sulfide crystals that are a common inclusion in opal from Wollo. Oblique fiber-optic illumination. Photomicrograph by Nathan Renfro; field of view 2.73 mm.

	Chatoyancy is not unheard of in opal, though it is quite rare in precious material. Cat’s-eye common opal from Tanzania owes its optical effect to arrays of parallel needles, while the asterism and chatoyancy unique to the precious opal of Spencer, Idaho, are due to the arrangement of the same silica micro-spherules responsible for its play-of-color. At least one cat’s-eye precious opal was observed to even “wink” at the viewer when viewed with opposing lighting (Summer 2003 Lab Notes, p. 148). This Ethiopian opal cabochon joins the rarefied group of chatoyant precious opal with its unusual phenomenal display of flashes and flames. @chapter:48 @chapter:0 @chapter:48