Publication Year: 2016 Title: Lead Glass–Filled Black Star Sapphire Abstract: Figure 1. This 25.10 ct black star sapphire was enhanced with lead glass. Photo by Jian Xin (Jae) Liao.

	Fracture and cavity filling of gemstones has been practiced for hundreds of years. In recent times, this treatment has become more sophisticated and widespread, particularly with the use of lead glass, which is most often seen in rubies. The addition of lead oxide (PbO) to silica glass lowers its working temperature and viscosity while raising its refractive index from approximately 1.5 to as high as 1.8. Thus, the filler has an RI that matches many gem materials, making fractures and voids virtually disappear. But the softness and low melting point of the filler create durability issues, especially in low-quality filled rubies (S.F. McClure et al., “Identification and durability of lead glass–filled rubies,” Spring 2006 G&G, pp. 22–34).

	Common inclusion features for lead glass–filled ruby composites include blue flashes from the fractures and trapped gas bubbles. Glass features can also be detected using Fourier-transform infrared (FTIR) spectrometry and energy-dispersive X-ray fluorescence (EDXRF) spectroscopy. But if the ruby has very few areas that are enhanced with lead glass, they may not be obvious under magnification, and FTIR and EDXRF may not detect them. Real-time X-ray (RTX) imaging systems, used by GIA to identify pearl growth features and confirm filling in diamonds, can be beneficial in differentiating between lead glass and ordinary glass filling in rubies and other gemstones. This is due to opacity differences, as lead glass has a lighter appearance than glass without lead. A combination of X-ray imaging and magnification is also capable of quantifying the extent of lead glass treatment performed on a gemstone.

	A 25.10 ct opaque black star sapphire (figure 1) was submitted to the New York laboratory for identification. The stone contained a few hairline fractures and dense golden silk needles. At first glance, the sapphire had a few features that would arouse suspicion for treatment, such as round cavities on the base and a few inconspicuous fractures (figure 2). The sapphire also had a specific gravity of 4.04, which is above the normal range for corundum. Natural black sapphire may have a higher SG due to abundant asterism-causing inclusions of rutile or hematite, both of which are denser than corundum. Because of the stone’s opacity, it was difficult to observe internal inclusions under magnification.

	Figure 2. Gas bubbles visible in the sapphire’s cavities (left) and a thin fracture with different surface luster (right) indicate the possibility of lead glass filling. Photomicrographs by Akhil Sehgal; fields of view 2.10 mm (left) and 3.90 mm (right).

	Using X-ray imaging analysis (figure 3), it was clear that the fractures and multiple cavities had been filled with lead glass, and this finding was confirmed by EDXRF. These properties would have been extremely difficult to see under normal visual magnification.

	Figure 3. Face-up (left) and profile (right) RTX images of the black star sapphire. The white areas indicate higher opacity in fractures and cavities, evidence of lead glass filling. Noticeable round gas bubbles are trapped in cavity fillings.

	This is the first example of a lead glass–filled black star sapphire examined in the New York laboratory. @chapter:9


Publication Year: - Title: Chasing the Rainbow: Australia Opal Fields Expedition Abstract: The authors have never met any other group as passionate about their work as the Australian opal miners. Photo by Andrew Lucas/GIA.

		Beware of the opal bug! It is a close kin to the love bug and, once bitten, there is no escape.

		—Len Cram, a Lightning Ridge “bush” scientist and world authority on Australian opals

	INTRODUCTION

	With the world's primary supply of black and boulder opal coming from its wild outback, Australia is synonymous with opal. Since the first recorded discovery of precious opal in the 1840s, its fabulous play-of-color has delivered excitement and delight to consumers all over the world.

	Chasing the Rainbow:Australia Opal Fields Expedition

	Journey with us into the Australian opal fields and see the passion in chasing the rainbow.

	In May 2015 GIA sent a group of field gemologists to the southern hemisphere to explore some famous opal fields, where they were impressed by the tenacious optimism of the miners and learned extensively about this breathtaking gemstone. The team included GIA field gemologists Vincent Pardieu and Andrew Lucas, G&G technical editor Tao Hsu, assistant field gemologist Victoria Raynaud, and field cameramen Didier Gruel and Didier Barriere Doleac.

	This exceptional black opal is called supernova and has a rare star pattern in its dramatically
	bright play-of-color. It also has a truly black background color. Photo courtesy Cody Opal.

The National Opal Collection in Sydney features a full 3-meter-long skeleton of an opalized pliosaur. Along with precious opals, opalized prehistoric fossils are the pride of the nation. Photo by Tao Hsu, courtesy Cody Opal.

	THE JOURNEY

		Between latitudes 22° and 31° South, and extending from longitude 145.30° across the Queensland and South Australian boundaries into the heart of the interior desert land, stretches a tract of country which presents many strange problems to explorers and others interested in the study of the earth’s formation.

		—Robert M. Macdonald, 1904

The GIA team from left to right: Didier Barriere Doleac, Tao Hsu, Andy Lucas, Vincent Pardieu, Victoria Raynaud, and Didier Gruel. Photo by Terry Coldham/GIA.

	Taking off from Sydney, the GIA crew traveled to North New South Wales and Queensland
	to explore four world-famous opal fields. Map adapted from Anthony Smallwood, 2014.

	The opal journey started at Lightning Ridge, New South Wales, the household name for black opal. In Lightning Ridge the team met multiple opal miners, cutters, and researchers who shared their techniques, experience, and passion for the opal industry. The authors also visited many characteristic opal shops and looked at the finished loose stones and jewelry pieces. Then we headed northwest to visit boulder opal fields. We spent one full day in each of the following fields: Koroit, Yowah, and Quilpie. Both open-pit and underground mines were covered by the team. (Please note that the Australian miners refer to open-pit operations as open-cut operations, which is reflected in the upcoming videos of the miners.) Finished boulder opal products were checked and recorded as well. Famous opal fields such as White Cliffs, Andamooka, and Coober Pedy along the southern and southwestern margin of the Great Artesian Basin were not covered in this trip. More detailed information about each location the GIA group visited will be provided in following Australian opal series articles.

	Vincent Pardieu selects black opal specimens from a mine run in Lightning Ridge,
	Australia. Photo by Victoria Raynaud/GIA.

Well-known opal expert Andrew Cody hosted the GIA crew in his opal store in Sydney. The store highlights Australia’s National Opal Collection. Field gemologist Andrew Lucas was impressed by the Cody brothers’ collection and their passion. Photo by Tao Hsu/GIA.

	THE OPAL FIELDS

Terry Coldham, with 50 years of experience in the Australian gem industry, graciously agreed to become our expert guide, taking us through the Australian opal and sapphire fields and sharing his wealth of knowledge. Photo by Vincent Pardieu/GIA.

	Australian opal is predominantly found in sedimentary rocks within the Great Artesian Basin. The Great Artesian Basin is the largest artesian basin on this planet and the main “water tank” that supplies inland Australia. The basin is the remnant of an inland sea filled with sediments. Some volcanic opals have been recovered, but production is very limited compared to sedimentary opal. Although the chemistry and the microscopic structure of opal have been well analyzed, the formation of this gemstone is still much debated within the research field.

	Artesian bores are very common in the Great Artesian Basin. They provide water for both
	residents and visitors. Along with opals, hot springs attract many tourists.

	Multiple models have been published with supportive evidence to demonstrate how opal formed. One certainty is that not all opal formed in the same way. Supply and transportation of silica, space for growth, sedimentation conditions, and ion exchange processes are some critical questions to be answered before any definitive model is constructed. During this visit we also found that although these opal fields have many things in common, such as Jurassic- and Cretaceous-period sedimentary host rocks, each one has its own characteristics.

GIA field gemologist Andrew Lucas interviews opal miner Mark Moore in his open-pit opal operation in Koroit. The geology is much easier to see in a large open pit like this. Photo by Tao Hsu/GIA.

	Our first stop is Lightning Ridge, synonymous in the gem industry with top-quality black opal. The town is located in northern New South Wales and close to the border between New South Wales and Queensland. Geologically, Lightning Ridge is situated in the Surat Basin, part of the Great Artesian Basin. The sedimentary host rocks are more or less horizontal with no deformation. Black opal occurs as nobbies and as seams. The stones are generally found between 6 to 18 meters below the surface. Also amazing in this field are the extraordinary opal fossils of the Cretaceous age. These fossils are considered a national treasure and are well preserved in the Australian Opal Centre for both exhibition and paleontological research. Known for its rich history of black opal mining, mineral water spas, and unique Australian outback lifestyle, Lightning Ridge has long been a tourism hot spot, with more than 90,000 visitors per year.

View Gallery

	Lightning Ridge Opal Field Gallery

	To the northwest of Lightning Ridge are the Queensland boulder opal fields. Boulder opal from Queensland has very bright play-of-color, which makes these stones extremely appealing. The stone is called boulder opal because it is always attached to its host ironstone. Though the sedimentary host rocks are very similar to those in Lightning Ridge, the opal occurs mainly in ironstone concretions or as pipes instead of nobbies. Seam opal can sometimes be found in Queensland fields. Though local miners give the ironstone concretions different nicknames, such as “nuts” or “lily pads,” based on their different shapes, they bear the same concentric internal structure. Opal can be found as the kernel of the “nuts,” between the concentric layers of ironstone or on the surface of the concretions. Certain opalized fossils were also recorded in this area, with plant fossils commonly seen.

	There are over a dozen boulder opal fields in Queensland. Some of them are still active
	while others are exhausted for commercial mining.

	There are more than a dozen boulder opal fields in Queensland; the GIA team visited Koroit, Yowah, and Quilpie. The Koroit opal field was first discovered in 1897, and the most recent mining activities started in 1972, when consumers regained interest in boulder opal and sales became more profitable. The mine operated by Mark Moore has both a large-scale open pit and a small-scale underground shaft. The stones from this mine are quite stunning, with a range of quality. Today Koroit is unquestionably one of the main boulder opal suppliers in Queensland.

View Gallery

	Koroit Fields Gallery

	Yowah is a small town southwest of Koroit. The name Yowah is from Yowah Creek, where people formed a large horse station in 1872. The small opal field was first discovered around the same time. This mining area is famous for its “Yowah nuts”—precious opal sometimes occurs as the kernel of ironstone nuts. The authors observed both large-scale mechanical mining and fossicking in this field. With necessary supply and food providers, plus the permanent hot spring bores, the town has become a popular tourism and fossicking destination.

View Gallery

	Yowah Boulder Opal Field Gallery

	Heading northwest from Yowah, we arrived at Quilpie. The town was officially granted the township in 1917, while opal was discovered in this area around 1885. It serves as a center for the southern Queensland opal industry and is a gateway to multiple historic boulder opal mines. Mining activities in this field all cluster to the west and north-northwest of the town. Here you can find some of the more productive mines in recent times. Known as the “home of boulder opal,” the area is the largest producer of this variety in the world. Now, like many other famous opal towns, Quilpie is also a tourist- and fossicker-friendly place. The group visited an opal shop in town and a large open-pit mine north of Quilpie, where the exposed ironstone nuts range from centimeters to over a meter in diameter. The mine owner also cuts and polishes some of their production, and finished product was shown to the authors.

View Gallery

	Quilpie Gallery

	THE STONES

	Opal is an amorphous form of silica, and precious opal shows the rainbow colors we call play-of-color, caused by the diffraction of light. Precious opal is rare as its structure is composed of tiny silica spheres tightly packed in a three-dimensional grid. Light is broken up into the colors of the rainbow by the tiny voids between the spheres. To give an idea of the size of the spheres, those that are 0.20 microns have spaces between them that diffract the light to cause a blue play-of-color; 0.25 microns, a green color; and 0.32 microns, a red color. These tiny spheres that are responsible for play-of-color require an electron microscope of at least 30,000X magnification to see them.

Opal cutter and carver Justine Buckley holds a 92-carat Lightning Ridge black opal that she cut. Photo by Andrew Lucas/GIA.

	The Australian opal miners, cutters, and dealers all repeated one important attribute of opal: it is the only stone that can show every color of the rainbow. Our trip focused on the areas that produce black opal and boulder opal, both types of opal famous from Australia. Both types possess a range of appearances; in fact every stone is unique with its combination of colors. All the members of the expedition found opal to be a captivating if not mesmerizing stone.

The day we visited the opal processing area, Frederic Mallock was processing several days’ mining production, and he found this striking black opal while we watched. Photo by Andrew Lucas/GIA.

	Black opal refers to opals that have a dark bodycolor when viewed from above. They can be almost transparent to opaque, with an endless variety of play-of-color. Black opal is considered the rarest and most valuable opal. Boulder opal has thin veins of precious opal in the host rock the opal formed in, which is usually ironstone. The opal forms as infillings in the cracks and spaces of the ironstone. Boulder opal is usually cut free-form and wavy to follow the contours of the opal.

This black opal in sandstone is referred to as a nodule or nobby. Photo by Robert Weldon/GIA, courtesy Cody Opal.

	Vincent Pardieu displays a classic example of a Koroit boulder opal. Photo by Victoria
	Raynaud/GIA.

	Add to the appearance equation the pattern of the play-of-color, the underlying bodycolor, the brightness of the rainbow colors, the number of colors, the dominant rainbow colors, the thickness of the seam of play-of-color or color bar, the depth of the transparency, and the shape of the stone, and it is easy to see why each opal is unique and why opal is considered by many gem experts to be the most complex stone to grade. While market preferences determine the values of different opal appearances, opal is truly a personal stone with a beauty that is very subjective.

	Perhaps one of the best summations of opal was given in the first century ad:

		For in them you shall see the living fire of the ruby, the glorious purple of the amethyst, the sea green of the emerald all glittering together in an incredible mixture of light.

		—Pliny the Elder

View Gallery

	Black Opal Gallery

View Gallery

	Boulder Opals Gallery

	THE PEOPLE

Opal miners like Colin Stelzer have an adventurous nature that is contagious, as geologist Tao Hsu discovered after taking a flight in an ultralight plane to view the mining terrain from the sky. Photo by Andrew Lucas/GIA.

	The striking impression when conversing with Australia opal miners is their fierce sense of independence. These are people who love their freedom and the ability to live their lives as they see fit. All of the miners we spoke to said they could never live any other way. These men and women reminded us of the U.S. cowboys who lived in the 1800s, forging their way west. The hardships and risks involved in their lifestyle seem trivial compared to that of the Australian opal miners.

View Gallery

	Australian Opal Miners Gallery

	The companies mining opal are really individuals. Often a company is a partnership with just a couple of people working a claim, or in some cases just one person. If there are employees, there are just a few. This is a world of the rugged individual. Miners not only mine the opal themselves but also keep the equipment going, make repairs, and handle everything necessary to maintain the operation.

	Opal miner Colin Stelzer proudly displays a nut from his family’s mine near Quilpie that
	might contain boulder opal. Opal mining is often a partner or family operation and often
	passed down from father to son. Photo by Andrew Lucas/GIA.

	Another factor that drew these people to the search for opal was the thrill of finding beautiful opals. Even with the gamble, the risks, and no assurances, the hope of a major find is strong enough to keep them going through the tough times. One miner explained that there was a four-year period in which he found no opal, and continuing was extremely difficult. Then he discovered a significant pocket of black opal in his mine, and that rush of adrenaline made it all worthwhile. There is no guarantee of finding pockets of valuable opal, and experience and knowledge greatly contribute to success, but perseverance is the key factor—and of course luck.

		I have known people that have been here for 50 years and never found more than $1,000 and people that have been here for ten minutes and found millions.

		—Kim, Lightning Ridge black opal miner

	All the opal miners conveyed this same feeling of euphoria when finding opal. Hope is the universal feeling among the miners—the hope of making the next big find and hitting that pocket of top-quality opal that will make all the hard work and patience worthwhile.

		Finding an opal is like an injection of endorphins…it is like Mother Nature teasing you, saying, ‘come on, a little bit further; a little bit further anything can happen. Your fantasy and your dreams might just come true just a few more inches.’

		—Frederic Mallock, Lightning Ridge black opal miner

	Frederic Mallock began helping his father mine opal when he was around 10 years old. He said the excitement is still there, but it is a different excitement. In the beginning it was like a fantasy. Now that he is seasoned with over 45 years of experience, he knows what is possible, but the thrill of discovery is still there, and the passion is as strong as ever. All the opal miners we met, whether black opal miners or boulder opal miners, said there was no other job in the world they would want. None of them could see themselves working in a corporation, sitting in an office, or being told what to do by anyone. All the miners gave a similar answer:

		[Expletive] no, mate; it is the best. Hey, I am my own boss. Nobody tells me what to do, when to do it, how to do it, and we are actually in with a chance the fantasy might come true.

		—Frederic Mallock, Lightning Ridge black opal miner

Frederic Mallock operates his opal digging machine to scrape away at the walls of the mine. Opal miners have an incredible drive. Besides mining, operating equipment, processing, sorting, and exploring, he and his partner also maintain the equipment. Photo by Andrew Lucas/GIA.

	Mark Moore mines boulder opal in Koroit from March through November, a couple of months longer than most, as the temperature reaches 48 degrees Celsius (118.4 degrees Fahrenheit) in the summer, heating people and machinery, with constant droughts. In the ingenious and independent spirit of opal miners, Moore has created a comfortable and harmonious environment in the outback. He has a greenhouse for growing vegetables, a water recycling system, and even a couple of bathtubs outside that are propped up so hot coals can be placed underneath to make homemade hot tubs.

Mark Moore makes the best out of his environment at his mining camp in the outback by incorporating a greenhouse for vegetables, a satellite dish, water recycling, and even homemade hot tubs. For a barbecue Moore goes out into the bush and hunts game like wild boar. Photo by Andrew Lucas/GIA.

	Many of the miners we met also cut their opal and sell the finished stones as well as rough. Some have even entered the retail business, opening shops in the towns near their mines, such as Lightning Ridge, Quilpie, Cunnamulla, and Yowah. Justine Buckley in Lightning Ridge is involved in not only mining but also cutting the opals, designing and creating jewelry, and even owning a retail store. This mine-to-market approach allows miners to maximize income by catering to wholesale markets as well as tourist markets, depending on which is stronger. In fact several miners we met in the black opal and boulder opal mining areas have adopted this business model.

Mark Hodges proudly stands outside his store, Sunrise Opals, in Quilpie. For Mark and his wife, Sandy, the artistic gratification of cutting opal and creating jewelry led to a retail business to sell their creations. Photo by Andrew Lucas/GIA.

	During our trip the free spirit of the Australian opal miners was best envisioned during a visit to Eric Stelzer’s boulder opal mine. Both Eric and his son Colin are avid ultralight pilots. Colin took the expedition group up one by one, flying over the mining area so they could photograph and better understand the nature of the deposit. This flight in the simplest of machines symbolized the uncontained spirit and minimalist lifestyles of the Australian opal miners.

Boulder opal miner Colin Stelzer’s passion for ultralight planes symbolizes the Australian opal miners’ independence, free spirit, and passion for adventure. Photo by Andrew Lucas/GIA. @chapter:37


Publication Year: - Title: Sunstone History and Lore Abstract: Discoveries of glittery sunstone rough led miners to establish claims in the US state of Oregon. – Robert Weldon, courtesy Sunstone Butte Mine

                      In the early 1800s sunstone was a little-known, rare, and costly gemstone. It wasn’t until finds in Norway, Siberia, and other parts of the world that sunstone became somewhat more widely recognized, more available, and less expensive. In the US state of Oregon in the early 1900s, there were reports of sunstone finds in ancient lava fields in a desert area called Warner Valley. Even earlier, Native Americans in that area might have been the first collectors of Warner Valley sunstones.

According to Native American legend, the blood of a great warrior – wounded by an arrow -  dropped onto pieces of Oregon sunstone. The blood carried his warrior spirit into the stones, coloring them with shades of red and giving them sacred power. A museum in Jacksonville, Oregon, includes sunstones in its display of Indian artifacts. In Oregon today, several mining claims produce enough of this unique material to supply mass marketers as well as carvers and high-end jewelry designers.

	This photo shows a large sunstone fragment said to be from among the early discoveries in Oregon’s Warner Valley.

	Ore Pit, a publication of Oregon State University’s mineralogy department, published this picture of a collection of sunstones from a Jacksonville, Oregon, museum’s display of early Native American sunstone artifacts. @chapter:18


Publication Year: 2018 Title: Supply Chain Transparency and Beneficiation Abstract: Figure 1. Swat Valley emerald yields fine precision-cut stones in small sizes. Photo by Albert Salvato.

As the industry sees technology become more involved in daily gem trading and responsible sourcing has become a hot topic, Jean Claude Michelou, the editor-in-chief of InColor and a veteran of the industry, shared his perspective about supply chain transparency, beneficiation in source countries, and recent development of a Nigerian sapphire mining project.

While the diamond industry is already applying the blockchain concept, Michelou believes it is also the future of the colored stone counterpart. Blockchain and cryptocurrency both have the potential to increase the transparency of the colored stone supply chain by digitally recording all trading activities between different parties involved in the gem trade. He pointed out why miners, dealers, big brands, and consumers all need more transparency. The big jewelry brands especially need transparency to reinforce brand image and consumer confidence. Therefore, he expects the real changes will start with these companies, and gradually other players will be drawn in.

Jean Claude Michelou and the Supply Chain
Jean Claude Michelou reviews factors that he believes will affect the gem and jewelry industry’s supply chain.
Michelou also sees the impending shortening of the supply chain, especially as new technologies such as mobile devices become readily available even in the very remote mining areas. Even though many do not welcome the disappearance of the middleman between the supplier and the end consumers, it is unavoidable if no extra value can be added other than sharing the margin with both ends.

For the past decade, Michelou has taken part in several beneficiation projects initiated by multiple organizations. One project he is highly involved with is in the Swat Valley emerald deposits of Pakistan. Before he joined this project, a partnership between the local miners and a foreign company worked quite well for a three-year period. The company bought all the finished stones that were cut and faceted by local cutters. When this partnership stopped for unknown reasons, Michelou was contacted by locals who knew of his expertise.

	Gemstone Samples from Pakistan and Afghanistan

Gemstone Samples from Pakistan and Afghanistan
Jean Claude Michelou displays emerald from Pakistan’s Swat Valley and lapis lazuli from Afghanistan.
There are three mines in Swat Valley. The one that this project is working on has about 80 to 100 individual tunnels. Trained local women, usually the wives of miners, can handle 1.5–3.0 ct round brilliant cuts very well. Michelou became the liaison between them and a luxury jewelry brand in Europe that offered these women training and paid them a $500 per month salary. If these rough emeralds were transported to Jaipur for faceting, the cost would in fact be lower. However, the luxury brands are willing to pay more to guarantee a transparent supply chain since it enhances their brand image for consumers who care about where the stones are from. It also improves their reputation with the local people. Even though many rough stones are still exported to other countries for further processing, at least a portion of them stay in Pakistan for services that benefit the community through employment and added value to the resource (figure 1).

Emerald Deposits of Pakistan’s Swat Valley
Jean Claude Michelou recounts mining and beneficiation efforts at the emerald mines in Pakistan.
Finally, Michelou talked about his involvement in a Nigerian sapphire mining venture. Although the project was delayed for eight months, it will be a large-scale operation with two washing plants. The first plant will have a washing capacity of 50 tons per hour. From his time spent in Nigeria and Pakistan, Michelou has rich experience working with the people at the source. He said that understanding the local culture is very important for any company or individual wanting to start a gem mining or trading enterprise in these source countries. His personal experience has told him that trying to adapt the local people to the Western way of doing business is a challenge, especially at the beginning stage of the collaboration. One must gradually prove to the locals that a different approach can produce results that will benefit them tremendously, and this will help to change their mindset.

Sapphire Mining in Nigeria
Jean Claude Michelou discusses a new large-scale sapphire mining venture in Nigeria. @chapter:38


Publication Year: - Title: Spinel History and Lore Abstract: This gem at the Chicago Field Museum of Natural History is inscribed with noor jahan, or “light of the universe.” - Courtesy "Gems and Gemstones:Timeless Natural Beauty of the Mineral World" by Lance Grande and Allison Augustyn, 2009. University of Chicago Press.

                      Spinel is a good candidate for the title of “History’s Most Underappreciated Gem.” Some ancient mines that supplied gems for royal courts from Rome to China produced spinel, but it was usually confused with better-known stones like ruby and sapphire.

In ancient times, the mines of central and southeast Asia yielded exceptionally large spinel crystals. These fine stones became known as Balas rubies, and some of them were the treasured property of kings and emperors, often passing through many hands as spoils of war. As a result, some of the world’s most illustrious “rubies” are actually spinel.

One of the most famous examples is the so-called “Black Prince’s ruby.” This historic crimson-red gem is set in England’s Imperial State Crown and displayed in the Tower of London. Smoothly polished and roughly octagonal in shape, it was probably mined in the mountains of Afghanistan. It first appeared in the historical records of fourteenth-century Spain, and was owned by a succession of Moorish and Spanish Kings before Edward, Prince of Wales—the “Black Prince”— received the stone in 1367 as payment for a battle victory.

Since then, many other English monarchs—including Henry VIII—have cherished the gem. It’s outlasted them all, surviving fires, attempted theft, and World War II bombing raids, to become—with the Koh-i-Noor diamond—one of the centerpieces of England’s Crown Jewels.

Another large spinel in the Crown Jewels, the “Timur ruby,” weighs over 350 carats. It, too, has a checkered history. Several Persian inscriptions carved into the gem testify to its age.

Modern technology hasn’t helped spinel’s confused identity as far as the general public is concerned. This is due largely to the widespread use of synthetic spinel as an imitation for many other gems. Most customers aren’t even aware that there’s a natural version of the stone. @chapter:25


Publication Year: - Title: Pearl Care and Cleaning Guide Abstract: Pearl’s Mohs hardness is 2.5, so care should be taken not to scratch it.

                      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.

Pearl is ranked 2.5 on the Mohs hardness scale, which means it’s very soft and easily scratched or abraded. But with reasonable care, pearl jewelry can be a lasting treasure.

Pearl’s toughness is usually good, but aging, dehydration, and sometimes excessive bleaching during initial processing might make some pearls more fragile.

Stability
High heat can burn cultured pearls or cause discoloration, splitting, or cracking.

Pearl is generally stable to light, but heat from intense light can cause dehydration and cracked nacre.

Pearl can be damaged by many chemicals and all acids. The list includes hair spray, perfume, cosmetics, and even perspiration.

Pearls might be dyed, impregnated, or coated. These treatments might alter over time. Bleaching and irradiation can be stable during normal wear.

	The colors of these freshwater cultured pearls are the result of dyeing. Dyed pearl colors can alter over time.

Cleaning
Pearls should never be cleaned in an ultrasonic or steam cleaner. It’s safe to use warm, soapy water for occasional, thorough cleaning. If the pearls are strung, be sure the string is completely dry before wearing.

For routine care, it’s best to wipe cultured pearls with a very soft, clean cloth after each wearing.

	With proper care cultured pearls can provide their owner with a lifetime of enjoyment.
	- Courtesy Albert Asher Pearl Co., NY @chapter:14


Publication Year: 2019 Title: Dyed Serpentine Imitating Sugilite Abstract: Figure 1. These two beads, 6.96 ct (left) and 2.25 ct (right), were identified as dyed serpentine. Photo by Diego Sanchez.

The Carlsbad laboratory recently received a parcel of mottled purple beads (figure 1). A 2.25 ct translucent reddish purple broken bead from this parcel (shown on the right in figure 15) was examined for an identification report. At first glance, based on the color and structure, the sample resembled sugilite. Standard gemological testing revealed a refractive index of 1.56, a specific gravity of 2.71, weak orange fluorescence in both long-wave and short-wave UV, and a dye band with a handheld spectroscope. Sugilite has an RI of 1.607–1.610 and an SG of 2.74, and may show a concentrated band at 600 nm that can be confused with a dye band. The bead showed uneven color and a fibrous structure under the microscope (figure 2). There were no obvious dye concentrations, but the orange fluorescence and dye band in the spectroscope indicated the presence of dye. By performing a simple acetone test, we were able to prove that the material had been dyed. A light pink streak was examined after rubbing the test sample on a tissue soaked with acetone. The specimen’s infrared spectrum was not consistent with sugilite but ended up matching well with serpentine. Chemistry collected via laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) was consistent with serpentine, ruling out the possibility of sugilite.

Figure 2. The fibrous internal structure of the specimen resembling sugilite was actually consistent with serpentine. Photomicrograph by Jessa Rizzo; field of view 4.11 mm.
Without advanced testing, it would have been difficult to conclusively identify this material as serpentine. This is the first time reddish purple dyed serpentine imitating sugilite has been examined in the Carlsbad laboratory, and gemologists should be aware of this imitation when examining sugilite. @chapter:39


Publication Year: - Title: From Elizabeth I to Elizabeth Taylor: Jewelry through the Ages Abstract: John Benjamin, left, spoke at a GIA Alumni Association London chapter meeting and shared the importance of looking at jewelry design in the context of its time. Photo © GIA

	John Benjamin, a long-time contributor of the BBC’s Antiques Roadshow, promised a “personal account of 450 years of jewelry in one hour and four minutes” when he visited a GIA Alumni Association’s London chapter meeting in December 2013. He delivered that and more as he treated over 50 alumni members and guests to a presentation full of passion, expertise and humor.

	Benjamin, an FGA and DGA with the Gemmological Association of Great Britain (Gem-A), started his career in 1972 at Cameo Corner, the celebrated Bloomsbury jewelers originally located a stone’s throw from GIA’s London campus. He worked for Phillips Fine Art Auctioneers for 23 years until he established his eponymous independent jewelry consultancy in 1999.

	He began his presentation in the 16th century by describing the attitudes toward jewelry and why people wore it. Status, along with magical and religious associations, were strong factors in people’s choices for adornment, he said. Elizabeth I, who reigned from 1558-1603, was the ultimate power dresser, according to Benjamin. He illustrated his point with a famous portrait of her bedecked in gold and gems, especially pearls.

	“She’s not just wearing jewelry, she’s groaning with it,” he said. “There’s so much on her, she might just fall over.”

	He reviewed the 17th century, when the first imitation gemstones made from paste were introduced, and the 18th century, which welcomed opportunities to show the glamour of diamonds ‒ especially when viewed by candlelight. Diamond bow jewelry, with the stones from India and Brazil mounted in silver, was fashionable during the period.

	Benjamin briefly touched on the sentimental, romantic look of the 1820s-30s; a period of nature and naturalism, such as a flower spray brooch, in the 1850s; and then tourist jewelry, created for Great Britain’s wealthy elite who started to travel, especially to Italy.

	“Jewelry needs to be seen in the context of its time,” Benjamin said, noting the lively, yet elegant, animal and insect jewelry that was popular in the 1880s-90s. The end of the 19th century heralded the introduction of mass jewelry production, exemplified by the prevalent “tatty silver brooches” in the U.K.

	The rise of the middle classes, Great Britain’s Empire and the discovery of diamonds in South Africa all contributed to a look that was all about diamonds from 1900 onward, he said. With the Kimberley discoveries democratizing diamond consumption, factories in northern cities, such as Birmingham and Chester, churned the goods out for an eager market. This led to the Arts and Crafts movement, a counterpart to commercialism. He cited brooches by the Gaskins as examples.

	Benjamin said the most important change in jewelry design at the start of the 20th century was the introduction of platinum – it gave rise to many great European jewelry houses, especially Cartier. The advent of World War I ushered in a change in buying habits and shifted the main jewelry buying market to the U.S., which remains the largest consumer globally. He called out the Hope diamond as a classic example of this change, saying he could not imagine what the Hope would sell for if put on the market today.

	The elegant jewelry of the 1920s and Art Deco in the 1930s gave way to very different and unusual designs in the 1940s-50s, with pieces that featured lots of colored gemstones, such as aquamarine, peridot, citrine and even zircon. Benjamin called this a defining era for women who were working and making their own jewelry purchases.

	“What did they want to wear? Everyday jewelry in 9k gold; inexpensive and hard-wearing to suit their new lifestyles,” he explained. Jewelers in London’s West End, such as Asprey and Hancock’s, satisfied the demand.

	Moving closer to the present day, Benjamin described the situation of the 1980s and 1990s as “What is real and what is not,” referencing the rise of synthetics and treatments that continue to escalate.

	Benjamin predicted that the next look will be defined by jewelry with an ethnic and indigenous look, reflecting the integrity, style and essence of the country in which it was made.

	Dennis Bellesort, GIA GG, a regular attendee and previous speaker, said he was pleased to hear Benjamin’s presentation. “He has a great eye for jewelry and possesses great words to express beauty,” he said.

	Benjamin thanked the GIA Alumni Association by saying the evening had been particularly invigorating for him since there were so many young people in the audience.

	“I wanted to excite you,” he said. “Jewelry and gemology is a lightning conductor into a fantastic career.” @chapter:16


Publication Year: 2024 Title: Challenges in Identifying Drilled Keshi Pearls Abstract: Lot of 40 drop and oval pearls, with the smallest weighing 0.62 ct and measuring 5.17 × 4.16 mm and the largest weighing 2.95 ct and measuring 9.53 × 6.65 mm. Photo by Gaurav Bera.
Distinguishing natural pearls from non-bead cultured (NBC) pearls, commonly referred to as “keshi” in the industry, has become increasingly complex. While traditional methods such as radiomicrography were once reliable for the identification of South Sea keshi NBC pearls, recent advances in pearl drilling techniques have rendered these conventional approaches less foolproof. As a result, there is a growing need for advanced data analysis to study the internal structure, chemistry, and other spectral features associated with the mollusk origin to enable reliable separation of natural from NBC pearls.
To further examine challenging structures, GIA’s Mumbai laboratory borrowed pearls represented as natural from a known source. The lot consisted of 40 white to light cream drop and oval pearls (28 undrilled, 7 drilled, and 5 partially drilled). The smallest weighed 0.62 ct and measured 5.17 × 4.16 mm, and the largest weighed 2.95 ct and measured 9.53 × 6.65 mm (see above). The pearls all looked new, with smooth, high-luster surfaces that were free of blemishes. Under 40× magnification, the surfaces showed well-defined overlapping fine aragonite platy structures that accounted for their silky surface sheen.
Energy-dispersive X-ray fluorescence revealed manganese levels ranging from below detection level to 33.80 ppm and higher strontium levels ranging from 1756 ppm to 3364 ppm. Most of the pearls showed an inert reaction under X-ray fluorescence, while some had a weak yellowish green reaction. The latter reaction accounts for the higher manganese levels recorded. The pearls emitted medium to strong yellowish green fluorescence under long-wave ultraviolet light and a similar weaker reaction under short-wave UV. Based on these analyses, a saltwater origin was confirmed for all of the pearls.
Examined with real-time X-ray microradiography (RTX), most of the pearls showed minimal growth arcs, and some revealed faint linear-looking features visible only in certain directions. External and internal features aroused suspicion that these pearls were NBC. Another important observation was related to the size and length of the drill holes. Given the importance of maintaining weight, it is customary to drill drop and oval pearls to approximately one-third of their length. These pearls, however, were drilled to a depth that covered more than two-thirds of their length, while others were fully drilled with oversized drill holes. This indicated the pearls were drilled with the specific intention of concealing internal structures (Summer 2023 Lab Notes, pp. 218–220).

RTX imaging was performed for all the pearls in three directions, with careful alignment along their lengths to detect the presence of any linear feature or its remnants resulting from the drilling process. In most cases, proving a cultured origin only through RTX imaging was challenging. Consequently, the structures were studied using X-ray computed microtomography (μ-CT) analysis, as shown in table 1. In pearls 1 and 2, both undrilled, RTX imaging revealed a few distinct growth arcs, but not much was visible at their centers. Pearl 1 exhibited a small suspicious linear feature along its length, while pearl 2 did not. Interestingly, μ-CT analysis revealed an elongated linear feature running along the length of both pearls, accompanied by a few growth arcs, with the outer nacre lacking many growth features.
Pearls 3 and 4 were partially drilled, and both exhibited drill holes of unusual length and size compared to those observed in natural pearls. RTX imaging showed a few growth arcs toward the outer nacre and minimal growth at the center around the drill hole area. When aligned along their lengths, remnants of a linear feature crossing the drill hole were clearly visible in pearl 3, whereas pearl 4 did not show any evidence of the linear feature. Similarly, μ-CT analysis on both pearls revealed remnants of the linear feature toward the end of their drill holes, indicating an unsuccessful attempt to remove the linear features. Pearl 5, which was fully drilled, had fine growth arcs along its shape in RTX imaging, with a faint shadow feature running parallel to the drill hole. Through μ-CT analysis, a linear feature near the drill hole area was clearly visible.
As observed, structures from the samples closely resembled those observed in South Sea NBC pearls from the Pinctada maxima mollusk (A. Homkrajae et al., “Internal structures of known Pinctada maxima pearls: Cultured pearls from operated marine mollusks,” Fall 2021 G&G, pp. 186–205). In particular, drop and oval pearls from this mollusk should be carefully examined to avoid misidentification as natural due to the absence of structure if only examined under RTX imaging.
Natural drop and oval pearls are highly valued, and those with exceptional appearance and size are not easy to find. In recent decades, some members of the trade have attempted to conceal the linear features visible in South Sea keshi pearls using film or dental X-ray machines and subsequent drilling to remove any evidence. This often results in remnants of the linear features being left behind, as observed in these samples. These remnants can only be identified by carefully aligning the pearls in RTX imaging and through μ-CT analysis. Such subtle features can be easily overlooked during testing, potentially leading to their misinterpretation and misidentification as natural pearls. It is therefore essential for the trade to remain alert and informed about these increasingly frequent practices. @chapter:14


Publication Year: 2023 Title: A Remarkable 16.71 ct Transparent Orange-Yellow Sodalite Abstract: A 16.71 ct transparent orange-yellow oval sodalite measuring 17.61 × 15.74 × 12.88 mm. Photo by Lhapsin Nillapat.
GIA’s Bangkok laboratory recently examined the 16.71 ct transparent orange-yellow faceted oval shown in the figure above. Standard gemological testing revealed the stone to be singly refractive with a refractive index of 1.484 and a hydrostatic specific gravity of 2.28. The stone showed strong orange fluorescence under long-wave ultraviolet light and weak orange with chalky white fluorescence under short-wave UV. Microscopic examination revealed internal features such as a fingerprint-like plane of two-phase fluid inclusions and numerous tiny transparent crystals. Raman spectroscopy analysis using 514 nm laser excitation showed several distinct peaks at 263, 294, 464, 969, 986, and 1058 cm–1, which are characteristic features of sodalite (B. Lafuente et al., 2015, http://rruff.info/about/downloads/HMC1-30.pdf). Energy-dispersive X-ray fluorescence also identified the main chemical composition as sodium, aluminum, silicon, and chlorine, consistent with sodalite, which falls into the feldspathoid mineral group Na8(Al6Si6O24)Cl2.
Sodalite is typically a semitransparent to opaque blue stone with calcite veining resembling lapis lazuli. However, it can occasionally exhibit other colors. The orange-yellow variety of sodalite is rare, and its color may be related to the presence of sulfide ions (F. Seel, “Sulfur in artwork: Lapis lazuli and ultramarine pigments,” Studies in Inorganic Chemistry, Vol. 5, 1984, pp. 67–89). Ultraviolet/visible spectroscopy showed an absorption band centered at approximately 480 nm, likely caused by heavy radioactive elements creating an unstable color center substituting for Cl– in a tetrahedron of Na+ ions (H. Annerstein and A. Hassib, “Blue sodalite,” Canadian Mineralogist, Vol. 17, 1979, pp. 39–46; P.S. Pizani et al., “Color centers in sodalite,” American Mineralogist, Vol. 70, 1985, pp. 1186–1192). This sodalite is exceptional for its color, transparency, and 16.71 ct size. To the author’s knowledge, this is GIA’s first encounter with a large faceted orange-yellow sodalite. @chapter:13


Publication Year: 2020 Title: Oiled Spinel Abstract: Figure 1. Bojan brand “King Ruby Red Oil” from Chanthaburi, Thailand, along with a parcel of rough Thai rubies purchased by the author in 2016. Note the red stain on the plastic bag. Photo by Wimon Manorotkul.

When it comes to clarity enhancement with oils and resins, a common belief is that the refractive index of the host gem must match that of the filler. If one follows this logic, it would seem that using oils or resins to clarity enhance corundum (n = 1.76) or spinel (n = 1.72) would not be at all effective, since there is a yawning gap in RI between those gems and that of any oil or resin.
Certainly, Burmese gem traders have never bought into that idea, for we regularly encounter oiled rubies, sapphires, and spinels from Myanmar. In fact, Burmese traders have told us that it is common practice to immediately immerse rough into oil after it is unearthed (figure 1). Oiling rough not only makes viewing the interior easier but also significantly enhances the gem’s clarity. In our experience, such treatment is almost never disclosed to buyers.
In 2013, while visiting various mines and markets in Myanmar’s Mogok Stone Tract, we were taken to a small house where a man was heat-treating spinel. Gems were placed in a crucible and heated for a period of time. Then, while still relatively hot, they were dumped into a vessel containing red oil. It was a remarkable piece of performance art. After the oil was wiped off, we could discern no change in color from the heating.
Because of the prevalence of oiling, we now check every stone with fissures for oil, no matter the origin or type of gem. This is typically done with a hot point under the microscope. The hot point gently heats the gem until, with oiled stones, the oil leaks out of the fissure in beads on the surface of the stone. With the exception of emerald, customers purchasing colored gems are not expecting them to be clarity enhanced. As one major Bangkok trader told us several years ago, “I cannot sell an oiled spinel.” For this reason, when we determine that a gem other than emerald has been fissure-filled with an oil or resin, we notify the client and allow them two opportunities to remove the filler before we issue the report.

Figure 2. On the left is the 3 ct spinel as initially submitted. At right is the same stone after removal of the oil. The difference is striking. Following cleaning, a large reflective fissure is visible parallel to the girdle plane. This demonstrates the ability of an oil/resin to mask fissures even when there is no close match in refractive index between the filler and host. Photos by Chanon Yimkeativong/Lotus Gemology.
In September 2020, Lotus Gemology received for identification a 3 ct spinel that originated from Mogok. We noticed a fissure on the pavilion running parallel to the girdle plane, and application of the hot point caused oil to leak out. After two rounds of oil removal by the client, the difference was truly remarkable. The gem was now disfigured by a highly reflective eye-visible fissure (figure 2).
This clearly demonstrates that oil can have a significant impact on the clarity of a gem even when there is a big difference in RI between the host and the oil. The greatest impact will be found in stones like this spinel, where fissures lie perpendicular to the viewing angle. @chapter:2


Publication Year: 1990 Title: Fall 1990 Gem News International Abstract: Diamonds
            Diamond Prospects in Brazil
            New Venture in Botswana
            New Sierra Leone Mining Policy
            Australian Firm Prospecting in China
            Goa, India, Seeking Diamond Merchants
            Prospects in India Worsen
            Diamond Prospecting in India
            Revised Figures for Kalimantan
            Sri Lanka Attracting Diamond Industry Investment
            Thailand Auctions Smuggled Diamonds
            New Diamond Discovery in USSR
            Soviet Delegation Visits Israel
            Eastern Europe Opens to Diamond Cutters
            Diamond Rush in Australia
Colored Stones
            Ancient Mushroom Inclusion in Amber
            Greenish Blue Cat's-eye Apatite
            Zimbabwe Emerald Update
            Unusual Cat's-eye Diopside
            Fine-Quality Chatoyant Iolite
            Gem Finds in Inner Mongolia
            Opal with True Chatoyancy
            Star Scapolite
            More Activity at the Sugilite Mine
            Unusual Carved Tanzanite
            Cat's-Eye Tanzanite
Enhancements
            Faceted Gems with Aqua Aura Enhancement
            New Opal Enhancement
            "Plastic"-Coated Sugar-Treated Opal
Synthetics and Simulants
            Knischka Synthetic Ruby Update
            Fluorite Imitating Emerald
            Imitation Jade Carving
Announcements
            Tucson Gem and Mineral Show 1991
            International Gemological Symposium 1991
            Updates from the State Gem Corporation of Sri Lanka

To view the full section, download the PDF above. @chapter:20


Publication Year: 2018 Title: Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design Abstract: Figure 1. Gianmaria Buccellati Foundation Award winner Catherine Zheng (center), with GIA president and CEO Susan Jacques and Gianmaria Buccellati Foundation chief officer of North American strategies Larry French. Photo by Kevin Schumacher.

The first annual Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design was presented on February 2, 2018, to GIA graduate Catherine Zheng (figure 1). The competition, open to students who successfully completed the GIA Jewelry Design course in 2017, recognizes artistic excellence in jewelry design. Zheng received the award for her rendering of an Art Deco–inspired pendant necklace. Zheng, who studied at GIA in Carlsbad, was one of 12 finalists from seven campuses whose hand-rendered designs were judged by a committee comprised of jewelry design, manufacturing, retail, and media experts. The finalists’ designs were on display and the recipient of the award was announced at the annual GIA alumni party held during the AGTA Gem Fair in Tucson.

The Gianmaria Buccellati Foundation sponsored the award as a way to inspire beginning jewelry designers and honor the work of the renowned jewelry design house’s founder, Gianmaria Buccellati. The 2018 competition is under way and open to students in GIA’s Jewelry Design course who meet the eligibility requirements. @chapter:36


Publication Year: - Title: Citrine History and Lore Abstract: A brooch from the Victorian era features an oval citrine with six ruby accent stones. - GIA & Tino Hammid

                      People have used quartz in jewelry for thousands of years. Egyptians gathered ornately striped agates from the shore and used them as talismans, the ancient Greeks carved rock crystal ornaments that glistened like permafrost, and the hands of Roman pontiffs bore rings set with huge purple amethysts. Natural citrine is rare, and today most citrine quartz is the result of heat treatment of amethyst quartz. Even so, gems from the Victorian era have surfaced, and it’s not hard to imagine that citrine was treasured even in earlier times.

	This gold pendant from the Victorian era features a citrine center stone. - GIA & Tino Hammid

	This ornate Victorian citrine brooch is thought to be from the 1860s. - Robert Weldon, courtesy Linda Zorozek @chapter:25


Publication Year: 2006 Title: The Impact of Internal Whitish And Reflective Graining on the Clarity Grading of D-To-Z Color Diamonds at the GIA Laboratory Abstract: Unlike many other characteristics that affect the clarity grade of a diamond, determination of the impact of “whitish” graining and “reflective” graining requires analysis that goes beyond visibility at 10× magnification. The importance of this determination is further underscored by the fact that such graining often is the only characteristic present in large, high-clarity, high-color diamonds. This article reviews the history of reporting on such graining by the GIA Laboratory, considers the causes of the different types of graining most commonly encountered, and examines the methodology and critical assessment GIA graders use to determine the impact of such graining on the clarity grade of a diamond. @chapter:31


Publication Year: 2022 Title: Gray “Spinel Sisters” Abstract: Figure 1. David Nassi’s 69.96 ct antique cushion-cut, loupe-clean gray spinel. Prized in the trade for its metallic-like sheen, gray spinel of this size, quality, and color is extremely rare. Photo by Robert Weldon.
At the AGTA show, 100% Natural Ltd. (New York) took center stage with some large, extremely rare gemstones spared of treatments of any kind. Two stones that caught the authors’ attention were a pair of exceptionally cut and nearly loupe-clean gray spinels weighing 69.96 ct (figure 1) and 11.78 ct (figure 2). There has been an increase in demand for gray spinel the past few years (Spring 2019 GNI, p. 130). Supply has remained relatively consistent, but larger, fine-quality stones are still quite rare.

Figure 2. The finest gray spinel is a pure neutral gray, without a blue or violet secondary color component, as exemplified by this 11.78 ct antique pear shape expertly cut by David Nassi. Photo by Robert Weldon.
Both of the gray spinels were cut from the same rough, weighing just over 220 ct and mined in Myanmar. Though famed for its rubies, Myanmar also produces equally fine red and pink spinel, as well as a range of other colors, including gray.
Master lapidarist and AGTA Spectrum Award winner David Nassi of 100% Natural Ltd. explained that gray spinel can appear lifeless and overly dark if cut poorly. His decision to create two “spinel sisters” from the same rough resulted from a fissure running through the large piece of rough (figure 3). The 11.78 ct stone provided more of a challenge, as the shape of the rough piece was a bit flat and asymmetrical when sawn from the larger stone. Inspired by a large Mozambique stone he cut many years ago, Nassi expertly fashioned this piece into an antique pear shape, perfectly complementing the larger 69.96 ct antique cushion cut (see video below).
Nassi and the authors agree that gray spinel has been an underappreciated treasure in the trade for a while now. Its presence at the AGTA show gives us hope that gray spinel is gaining the popularity it deserves.

Figure 3. The large rough gray spinel before (left) and after being sawn (right) because of a fissure in the rough. Not pictured is an additional small chipped-off piece weighing 3.32 ct, leaving open the possibility of a future third spinel sister. Photos courtesy of David Nassi.

	David Nassi Cutting Gray Spinel @chapter:3


Publication Year: - Title: Landmark Articles from Gems & Gemology Abstract: Gems & Gemology, GIA’s peer-reviewed quarterly journal, has had far-reaching effects on the science of gemology. For eight decades, its reporting has informed scientists and researchers, and educated generations of gem and jewelry professionals.

We asked the magazine’s editor and key contributors to review the journal’s body of work, and select articles they considered to be especially significant. After reviewing this treasure trove of materials, they picked ones that were particularly important to advancing gemological knowledge and providing practical insights to the gem and jewelry industry.

We share with you their selections.

A Solution to Diamond Color Grading Problems
By Robert M. Shipley and R.T. Liddicoat
FALL 1941, VOL. 3, NO. 11, PAGES 162-167

Robert Shipley Sr. and Richard Liddicoat describe methods for evaluating the color of colorless to light-yellow diamonds by the use of a standardized light source for viewing; and a prototype colorimeter for grading the color against a graduated color scale (which would later become the D-to-Z color grade scale).

The GIA diamond grading system was introduced in the early 1950s, with the first diamond grading reports issued in 1955. It is now the international standard for evaluating diamond quality.

New or Unusual Gem Materials Encountered in the Institute’s Gem Trade Laboratories
By G. Robert Crowningshield
SUMMER 1957, VOL. 9, NO. 2, PAGES 35-37, 61-62

Robert Crowningshield’s debut column describes new and interesting gem materials submitted to GIA for examination. Nearly 60 years later, reports on gem materials still appear in the “Lab Notes” section of the journal.

An Introduction to Spectroscopy in Gem Testing
By G. Robert Crowningshield
SUMMER 1957, VOL. 9, NO. 2, PAGES 46-55, 62

In the early 1950s, GIA lab staff used a spectroscope pioneered in the United Kingdom to identify diamonds and colored gemstones. During the next few years, Robert Crowningshield became one of the masters in using the spectroscope for studying gems, and also created hand-drawn patterns of spectral bands of a wide variety of gem materials.

Here Crowningshield describes how gemologists can use the spectroscope. Reproductions of a number of his spectra drawings are included. The spectroscope remains one of the most important instruments for gem testing.

Developing the Powers of Observation in Gem Testing
By R.T. Liddicoat
SUMMER 1962, VOL.10, NO. 10, PAGES 291-303

Richard Liddicoat describes methods for observing key features in gem material to determine their identity. More than 50 years later, these methods remain an essential component of GIA gem identification courses.

Rapid Sight Estimates of Diamond Cutting Quality
By R.T. Liddicoat
FALL 1962, VOL. 10, NO. 11, PAGES 323-335

The face-up appearance of a diamond depends upon the proportions of the facets and their related angles. Richard Liddicoat describes visual techniques that allow gemologists to estimate important proportion values.

The Characteristics and Identification of Filled Diamonds
By John I. Koivula, Robert C. Kammering, Emmanual Fritsch, C.W. Fryer, David Hargett, and Robert E. Kane
SUMMER 1989, VOL. 25, NO. 2, PAGES 68-83

Filling surface-reaching breaks with a special glass can hide clarity characteristics and improve the apparent clarity of a diamond. This is the most widespread treatment used on colorless and near-colorless diamonds. The authors describe the visual clues gemologists can use to recognize clarity-treated diamonds.

Color Grading of Colored Diamonds in the GIA Gem Trade Laboratory
By John M. King, Thomas M. Moses, James E. Shigley, and Yan Liu
WINTER 1994, VOL. 30, NO. 4, PAGES 220-242

Colored diamonds are the most valuable and some of the rarest gem materials in the marketplace. The procedures used by GIA to observe and describe the color of these diamonds, and the addition of “Fancy grade” terms are detailed here.

Beryllium Diffusion of Ruby and Sapphire
By John L. Emmett, Kenneth Scarratt, Shane F. McClure, Thomas M. Moses, Troy R. Douthit, Richard Hughes, Steven Novak, James E. Shigley, Wuyi Wang, Owen Bordelon, and Robert E. Kane
SUMMER 2003, VOL 39, NO. 2, PAGES 84-135

Heating is the most widely used treatment to change the color or appearance of ruby and sapphire. This process is often augmented by the diffusion of certain elements into corundum to produce a surface-related color zonation. John Emmett and others describe the various mechanisms used to create or modify color in corundum by heating and diffusion treatments.

A Foundation for Grading the Overall Cut Quality of Round Brilliant Cut Diamonds
By Thomas M. Moses, Mary L. Johnson, Barak Green, Troy Blodgett, Kim Cino, Ron H. Guerts, Al M. Gilbertson, T. Scott Hemphill, John M. King, Lisa Komylak, Renee M. Renitz, and James E. Shipley
FALL 2004, VOL. 40, NO. 3, PAGES 202-228

The foundation of the cut grading system for round brilliant-cut diamonds was created using a decade of work of mathematical models of light interacting with polished diamonds, along with numerous observations of a variety diamonds. It started appearing on diamond grading reports in 2006. It is described here.

Color Grading “D-to-Z” Diamonds at the GIA Laboratory
By John M. King, and Ron H. Guertz, Al M. Gilbertson, and James E. Shigley
WINTER 2008, VOL. 44, NO. 4, PAGES 296-321

The authors describe key concepts for evaluating color in colorless to light yellow diamonds. Grading color remains an essential component of the quality grading system of diamonds, which GIA introduced in the early 1950s. @chapter:29


Publication Year: 2014 Title: Books: Heavenly Bodies: Cult Treasures and Spectacular Saints from the Catacombs Abstract: By Paul Koudounaris, 192 pp., hardcover, illus., publ. by Thames & Hudson, 2013, $29.95.

              In Heavenly Bodies, Paul Koudounaris has chosen an unusual topic for research: The idea of honoring the early martyrs by adorning them with lavish metalwork and gemstones. One initial impression might be that this work has a religious theme, yet it covers many interesting historical points not tied to religion. Koudounaris’s impartial research on the so-called catacomb saints gives insight into aspects of the schism within the Christian faith in Europe following the Protestant movement.

The book examines the skeletons discovered by chance in Roman catacombs (underground tombs) in the mid-16th century. The Vatican declared the tens of thousands of skeletons found in these vast underground labyrinths to be remains of early Christian martyrs. The location alone was sufficient proof of martyrdom, and no further evidence was sought to declare their authenticity. The Catholic Church was delighted to have a substitute for the holy relics that were largely destroyed during the Protestant Reformation in German-speaking European countries. The skeletons were examined and authenticated in Rome, then dispatched to other Catholic parishes, mainly in Germany and Switzerland.

Upon their arrival, the skeletons were lavishly adorned. Fragile bones would be reinforced by animal glue; missing parts would be replaced by wood or sometimes metal. They would be preserved with wax and meticulously covered with gauze, silk, and gemstones and pearls set in silver. The decorative work took hundreds of hours and was performed by nuns and silversmiths on each skeleton that went on display. Some churches had to wait until they could collect the funds for this costly task. It is interesting that when the church couldn’t afford natural gems, it compromised and used imitation stones, and even these weren’t inexpensive at the time. Many devotees supported the cause by donating jewelry and money. After all, these luxuriously decorated skeletons were a great attraction and a source of income for the church.

By the 19th century, pride in the catacomb saints had faded. The revered relics became an embarrassment due their questionable origin. The Catholic Church itself began to doubt the authenticity and the necessity of these objects. Once considered remains of the saints, the ornately embellished skeletons began quietly disappearing from the public scene. Today, a few churches in Switzerland and Germany still maintain them, but not on public display. Paul Koudounaris was granted access to the few remaining specimens for research, and the book is magnificently illustrated with more than 100 of his photos.

Heavenly Bodies is an illuminating read for jewelry historians and gemologists alike, as it reveals an unusual aspect of jewelry and use of gems. @chapter:21


Publication Year: - Title: GIA's Gübelin Gem Project: Various Gems, Kornerupine - Natrolite Abstract: Kornerupine
Photo by Robert Weldon/GIA, courtesy Dr. E. J. Gübelin Collection
GIA Collection 34365

Among the collection assembled by Dr Edward Gübelin are a number of uncommon gemstones from many worldwide localities. Documents, like the ones below, present information on gemstones that range from occasional use in jewellery to those that are quite rare and seldom faceted because of the lack of suitable starting material.

34702

			2.60 ct jeremejevite
			Namibia (PDF)

34365

			1.64 ct kornerupine
			Kenya (PDF)

34366

			1.80 ct kornerupine
			Kenya (PDF)

34368

			5.54 ct kornerupine
			Kenya (PDF)

34067

			3.96 ct kornerupine
			Sri Lanka (PDF)

34848

			4.90 ct kornerupine
			Sri Lanka (PDF)

34069

			7.11 ct kornerupine
			Sri Lanka (PDF)

34851

			7.43 ct kornerupine
			Sri Lanka (PDF)

34850

			7.86 ct kornerupine
			Sri Lanka (PDF)

34063

			11.19 ct kornerupine
			Sri Lanka (PDF)

35016

			4.39 ct kornerupine
			Tanzania (PDF)

34274

			6.10 ct kyanite
			Brazil (PDF)

34276

			7.81 ct kyanite
			Brazil (PDF)

33854

			8.37 ct kyanite
			Brazil (PDF)

33849

			18.43 ct kyanite
			Brazil (PDF)

34352

			4.44 ct kyanite
			Kenya (PDF)

33835

			2.77 ct kyanite
			Madagascar (PDF)

35630

			15.30 ct kyanite
			Myanmar (PDF)

33839

			3.68 ct kyanite
			Nepal (PDF)

34742

			5.78 ct kyanite
			Nepal (PDF)

34964

			3.85 ct kyanite
			Switzerland (PDF)

34993

			15.81 ct kyanite
			Tanzania (PDF)

35283

			3.55 ct kyanite
			Zimbabwe (PDF)

35287

			5.05 ct kyanite
			Zimbabwe (PDF)

35579

			3.51 ct leadhillite
			Namibia (PDF)

35442

			1.52 ct leucite
			Italy (PDF)

35411

			12.93 ct magnesite
			Brazil (PDF)

34483

			3.51 ct manganotantalite
			Mexico (PDF)

35448

			5.51 ct manganotantalite
			Mozambique (PDF)

35449

			9.90 ct manganotantalite
			Pakistan (PDF)

35453

			4.46 ct mimetite
			Namibia (PDF)

35581

			1.01 ct monazite
			Brazil (PDF)

35456

			1.34 ct montebrasite
			Brazil (PDF)

34258

			46.28 ct montebrasite
			Brazil (PDF)

35836

			3.58 ct musgravite (magnesiotaaffeite)
			Locality not stated (PDF)

35190

			4.54 ct natrolite
			The United States (PDF) @chapter:37


Publication Year: 2022 Title: Four-Rayed Star Chrysoberyl Abstract: Figure 1. Chrysoberyl showing two bands of reflective light displaying four-rayed asterism. Photo by Shunsuke Nagai.
GIA’s Tokyo laboratory recently received a brownish green cabochon set in a white metal ring with numerous near-colorless marquise brilliants and tapered baguettes (figure 1). The stone measured approximately 12.21 × 9.20 × 8.17 mm. Standard gemological testing showed weak green and yellow pleochroism and a spot refractive index reading of 1.75, as well as a strong diagnostic iron-related 444 nm band observed with a handheld spectroscope. These properties were consistent with chrysoberyl. At first glance the cabochon seemed to display chatoyancy, which would make this a cat’s-eye chrysoberyl. However, there was not just a single band of reflected light but two bands intersecting at a 90° angle, so the phenomenon was actually four-rayed asterism.

Figure 2. In the star chrysoberyl, short needles and dense minute particles were perpendicular to each other. The particles reflect light and caused the thick band’s orientation (seen diagonally here). Photomicrograph by Yuxiao Li; field of view 3.7 mm.
Chatoyancy is usually created by light reflecting off of parallel needles or tube-like inclusions in a cabochon-cut gemstone. Microscopic observation revealed two sets of inclusions. One consisted of dense minute particles aligned in one direction producing a thick band of reflected light (oriented diagonally in figure 2). The other set was composed of needles oriented along the same direction as the thick band of light. These needles created a second band of reflected light perpendicular to the orientation of the needles. Together, these reflected bands of light resulted in the unique combination of two intersecting cat’s-eyes.
Four-rayed stars are common in diopside, garnet, and spinel. But they are very rare in chrysoberyl, which makes this stone notable. @chapter:19


Publication Year: 2023 Title: Treated HPHT Laboratory-Grown Diamond with Dramatic Color Zoning Abstract: Figure 1. This 2.20 ct Fancy Deep brownish orange treated HPHT-grown diamond owes its distinctive appearance to multiple defect concentrations created within the various growth sectors. Photo by Diego Sanchez.

Figure 2. The square-shaped cubic {100} growth sector appears pink when viewed through the table (left) and more of a purple color when viewed through the pavilion (right). The surrounding regions appear predominantly yellow due to the presence of single nitrogen. Photomicrographs by Nathan Renfro; fields of view 4.23 mm and 4.50 mm.
Recently, the Carlsbad laboratory examined a 2.20 ct laboratory-grown diamond that received a color grade of Fancy Deep brownish orange (figure 1). Spectroscopic analysis indicated high-pressure, high-temperature (HPHT) growth methods and subsequent irradiation and annealing to create nitrogen vacancy centers. Infrared absorption spectra collected from the entire stone identified it as type Ib with a concentration of ~5 ppm of single isolated nitrogen. The diamond was distinctive because of a pronounced pink square under the table facet within the cubic {100} sector. The other major growth sectors (e.g., {110}, {111}) surrounding the central cubic sector appeared yellow due to single isolated nitrogen. The pink growth sector displayed pronounced reflections when viewed through the pavilion facets and had more of a purple color (figure 2).

Figure 3. Room-temperature Vis-NIR absorption spectra were collected using a reflectance probe to document the absorption differences between the pink central region and the surrounding areas. The red trace shows a pronounced absorption associated with NV– along with Ib (i.e., single nitrogen) absorption. The yellow trace also shows Ib absorption along with a minor contribution of NV0 and small peaks associated with GR1 (741.2 nm) and nickel (883/884 nm). Spectra are offset vertically for clarity.
Visible/near-infrared (Vis-NIR) absorption spectra were collected from the center of the table using a reflectance probe positioned to show pink fluorescence. The probe was then repositioned toward the crown facets that did not show pink fluorescence (figure 3). The spectra from both areas indicated type Ib-related absorption at low wavelengths. Additionally, the pink color region was dominated by the NV– center (zero-phonon line, or ZPL, at 637 nm) and its associated sidebands, while the surrounding yellow regions had minor absorption from NV0 (ZPL at 575 nm). This difference in NV-related absorption shifts the transmission window from pink to yellow.
The uptake of single nitrogen is generally lower in {100} growth sectors than in {111} sectors (R.C. Burns et al., “Growth-sector dependence of optical features in large synthetic diamonds,” Journal of Crystal Growth, Vol. 104, 1990, pp. 257–279). However, the concentration of single nitrogen (necessary to ultimately create NV centers) can be increased within the cubic sector through lower growth temperatures (S. Satoh et al., “Differences in nitrogen concentration and aggregation among (111) and (100) growth sectors of large synthetic diamonds,” Science and Technology of New Diamond, KTK Scientific Publishers/Terra Scientific Publishing Co., Tokyo, 1990, pp. 351–355). It is possible that such growth conditions were used with this diamond in order to incorporate sufficient nitrogen within the cubic sectors, which were subsequently transformed to NV centers with treatment.

Figure 4. PL mapping using 532 nm excitation at liquid nitrogen temperature shows pronounced differences in defect concentrations based on growth sector. The NV– intensity (left, normalized to the diamond Raman line) is highest within {100} and much lower within the other regions. The normalized NV0 defect intensity (right) was detected throughout the diamond but was noticeably higher within {111} sectors.
Within the cubic sector, photoluminescence (PL) mapping showed a significantly higher concentration of NV– compared with the other major growth sectors (e.g., {110} and {111}), while the concentration of NV0 was lower (figure 4). The presence of donors, such as single nitrogen, can often shift the balance between neutral and negative NV centers so that NV– is enhanced in diamonds with single nitrogen (I.A. Dobrinets et al., HPHT-Treated Diamonds: Diamonds Forever, 2013, Springer-Verlag, Berlin). The presence of single nitrogen can be related to an elevated concentration of NV– within the cubic sector; however, in the {111} sectors, NV0 dominates over NV– despite the appreciable concentrations of single nitrogen. This can likely be attributed to the {111} sectors also preferentially incorporating boron. Although boron was not detected within the infrared absorption spectra for this stone, it is often present in HPHT-grown diamond, even at low concentrations. Since boron preferentially incorporates within {111} sectors (U.F.S. D’Haenens-Johansson et al., “Synthesis of diamonds and their identification,” Reviews in Mineralogy and Geochemistry, Vol. 88, No. 1, 2022, pp. 689–753), these acceptors could shift the charge balance within those areas, thus causing the preferential creation of NV0 over NV–.
PL mapping highlighted other pronounced differences between the growth sectors. The GR1 defect (V0) and TR12, an irradiation-related defect with ZPL at 469.9 nm, was highest in {110} and negligible in {100}. The nickel-related doublet at 883/884 nm was extremely high in {111} and negligible in {110} and {100}.
This HPHT-grown diamond is a notable example of growth techniques and treatment engineering producing a combination of defects that is visually interesting. The faceting approach, in which the pink growth sector was positioned under the table facet, served to enhance the dramatic appearance. @chapter:15


Publication Year: 1982 Title: Radioactive Irradiated Spodumene Abstract: During routine testing, a parcel of spodumene imported from Brazil was found to be radioactive. Detailed analysis showed that individual stones had levels of gamma ray emission far above those acceptable for jewelry purposes. Gamma ray spectroscopy revealed that they had been irradiated with neutrons. The colors of these stones are similar to those observed in citrine and have no counterpart in untreated spodumene. They range from brownish orange through orange to orange-yellow and greenish yellow. @chapter:17


Publication Year: 2003 Title: Fall 2003 Gem News International Abstract: Diamonds
            Australia’s Largest Diamond Crystal Found at Merlin
            Update on Diamond Mining and Exploration in Northern Alberta, Canada
            Profile Cut Diamonds
Colored Stones and Organic Materials
            An Alexandrite-Emerald Intergrowth
            Amethyst from Nigeria
            New Hiddenite Discovery in Historic North Carolina Location
            Update on Sapphires, Pezzottaite, and other Gems from Madagascar
            Update on Mining and Marketing Gems in Mogok, Myanmar
            “Star” Obsidian
            An Unusual Star Quartz
            Star Sunstone from Tanzania
            More Curiosities from Tucson 2003
Synthetics and Simulants
            Chemical Vapor Deposition (CVD): A Gem-Quality Laboratory-Created Diamond Source             “Mermaid Crystal,” an Opal Simulant
            Synthetic Spinel with Unusual Inclusions
Treatments
            HPHT-processed Diamonds from Korea
            Tourmaline with an Iridescent Coating
Miscellaneous
            Heat Treatment and Gem Cutting Facility in Madagascar
            Plans for a Gemological Institute in Madagascar
Conference Reports
            Gem Presentations at the GAC-MAC-SEG Meeting
            8th International Kimberlite Conference
Announcements
            John I. Koivula Wins AGS Liddicoat Journalism Award for G&G Article
Conferences
            Québec Exploration 2003
            Gems at the MRS Fall Meeting
            PDAC 2004
Exhibits
            Chanel Collection Privée
            Treasures of Ancient Egypt at the New Orleans Museum of Art

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


Publication Year: 2020 Title: American Gem Society Upcoming Events Abstract: The American Gem Society (AGS) will hold virtual and in-person educational events at the newly announced Confluence, slated for April 26. This event aims to provide industry professionals with content specifically designed to increase sales and refocus business strategy. Katherine Bodoh, CEO of AGS and AGS Laboratories, is pleased to offer a selection of programs that speak to “vital subjects our members need to reach new heights in their professional development.” Members will also have access to AGS PRO, a learning portal filled with an array of relevant topics from leading experts in the field.
Conclave, which normally takes place each April, has been rescheduled for September 12–14, 2021. It will be held at the Sheraton Dallas Hotel in Dallas, Texas. @chapter:28


Publication Year: 2020 Title: CVD Landscape Abstract: Figure 1. GIA-grown rough CVD diamond weighing 5.8 ct, photographed under daylight conditions. Photo by Towfiq Ahmed.
Fluorescence is an integral part of diamond analysis that displays varying growth defects. Each color provides visual clues to the growth chemistries and defects formed. Gemologists use this data along with other spectroscopic features to determine a diamond’s origin and treatment history. The fluorescence features in this experimental CVD block grown by GIA (figure 1) are reminiscent of a landscape with trees reflecting into a lake during a sunset (figure 2, illuminated using a DiamondView equipped with a UV light).

Figure 2. DiamondView fluorescence image of a 5.8 ct GIA-grown CVD block measuring 7 × 7 × 7 mm. Photomicrograph by Stephanie Persaud.
CVD diamond technologies have improved vastly over the last decade. Researchers at GIA grew this CVD block over several growth runs to gain a better understanding of CVD diamonds. This block captures the essence of nature within a laboratory setting. @chapter:15


Publication Year: 2019 Title: Appendix 3: Calculation Method for Tourmaline Species Classification Used Here Abstract: The simplified procedure of the method can be described as follows:

Use 29Si as internal standard to calculate raw ppmw.
Convert raw ppmw to atoms per formula or moles.
Calculate Li and B atoms per formula based on stoichiometric chemical formulae.
Convert this formula from atoms to wt.% oxides and ppmw.

The exact procedure of the method is given below:
There are three variables used in this method: Limole, Bmole, and A.
Limole is the Li (in moles) before normalization.
Bmole is the B (in moles) before normalization.
A is the normalization factor, which converts moles of each element into atoms per tourmaline formula unit.
To calculate values of the three unknown variables, three independent equations are required.
Function 1: The numbers of ions in the formula are based on 31 (O, H) per chemical formula.

Assuming stoichiometric amounts, there are three atoms of B per formula unit

. This reduces the number of independent variables to two:

Y is the total of ppm (mole) oxygen to charge balance cations except for Li and B before normalization. Y is measured by LA-ICP-MS. All element (Rppmw) symbols used below represent ppmw of the elements before normalization (this statement holds for all other uses).

Function 2: The summation of cations in Y-, Z-, and T-sites equals 15.

X is the summation of cations per formula in Y-, Z-, and T-sites before normalization. X can be measured by LA-ICP-MS. All element (Rppmw) symbols used below represent ppmw of the elements before normalization.

By solving the following equation set, normalization factor A and values for tourmaline species classification are obtained.

Finally, using A, the raw data for the major elements in ppmw is converted to atoms per formula unit. This is done by dividing the ppmw concentration of each element by its atomic mass and then multiplying by A. The concentration of each element in atoms per formula unit is used for the tourmaline species classification. @chapter:5


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

Abstracted by Michele Kelley @chapter:24


Publication Year: 1982 Title: Jade Forms from Ancient China Abstract: The attraction of jade is two-fold: the nature of the material and the way it is used. The color, texture, and feel of jade are easily appreciated, but the symbolism of the motifs in which it is carved is an enigma to many of the stone's admirers. This article briefly examines some of the symbols used in jade carved in China, including an introduction to the religions on which much of this symbolism is based. By mastering these basic symbols and the philosophy behind them, collector and seller alike can gain greater understanding of the cultural and philosophical meaning of the art involved in a particular piece. @chapter:25


Publication Year: 1985 Title: Pearl Fashion Through the Ages Abstract: This article traces the use of pearls from antiquity to the initial appearance of cultured pearls in the 1920s. The first section touches on the early fascination with pearls as revealed through historical literature, including Cleopatra's pearls, Roman pearl jewelry, and medicinal pearl recipes of the Middle Ages. During the Renaissance, Spain's exploration of the New World resulted in the discovery of vast quantities of valuable pearls that were eventually spread throughout Europe. Queen Elizabeth I's magnificent collection of pearls and the intriguing baroque pearl figurines of the later Renaissance are also discussed. The article concludes with a review of pearl fashion from 1800 to 1930, including delicate Victorian seed-pearl jewelry, Queen Alexandra's dog-collar chokers, and Art Deco pearl-inlaid jewelry. @chapter:21


Publication Year: - Title: Career Fair Matches Talent and Opportunity Abstract: Jewelry designer Alishan Halebian coaches an aspiring designer at a GIA Career Fair in Carlsbad. Career coaching sessions make it possible for jewelry industry hopefuls to meet with industry leaders to ask questions and seek advice.

		The GIA Jewelry Career Fair was created in 1991 to more effectively match professionally trained talent with gem and jewelry industry employers. It was the first time – other than through traditional job search methods – that prospective employers and employees could meet one-on-one in an organized, informative and supportive setting. Tens of thousands of aspiring professionals have attended the nearly 50 Career Fairs held to-date.

		More than two decades have passed since the inaugural event, but the need to bring together talented people and prospective employers in the gem and jewelry industry remains strong. GIA has broadened the global reach of the event to meet this ongoing challenge and has held Career Fairs at the Institute’s world headquarters in Carlsbad, New York, Las Vegas, Los Angeles and India.

		Each event kicks off with a panel presentation by key industry leaders who offer comments on the current market and career advice for those entering it. More themed panel discussions follow and have included discussions on creative careers, how to manage your designs and the exciting world of the celebrity stylist. Panel participants often share their personal stories of success and offer motivation and inspiration for attendees.

		One-on-one coaching sessions and the recruiting aspect of the event give prospective employees the opportunity to get firsthand advice on how to create a successful and fulfilling career and to meet with key leaders and recruiters to learn about specific jobs in the gem and jewelry industry.

		“Career Fair has evolved to become much more than a way for students and job seekers to embark on new careers,” said Kathryn Kimmel, co-founder of the event and vice president and Chief Marketing Officer for GIA. “It’s brought the best and brightest professionals along with innovative ideas to the industry, and it’s provided a valuable platform for established leaders in the gem and jewelry field to give back.”

	Left: Attendees at GIA Career Fair in India meet with recruiters. Right: The audience listens during a panel presentation in Carlsbad. Attendees are encouraged to ask questions at the end of panel presentations.

	Left: A recruiter meets with a job seeker at GIA Career Fair in Carlsbad. Most recruiters in attendance are actively seeking new employees and are eager to meet with professionally trained graduates. Right: Gem and jewelry industry leaders discuss the job market and give career advice during a Carlsbad presentation. @chapter:36


Publication Year: 2009 Title: Gem-Quality Andalusite from Brazil Abstract: Widely known as a rock-forming mineral, andalusite is not frequently encountered as a gem material. This article documents the gemological and spectroscopic properties of numerous rough and cut samples of gem-quality andalusite from Brazil. The color varied from yellowish green and green to brownish pink (including bicolored green and brownish pink), and some were faceted with the pleochroic colors attractively oriented. Transparent samples of the chiastolite variety of andalusite were particularly interesting. All the samples displayed a complex growth pattern, with the various inclusions oriented along the growth directions. Heat treatment produced subtle changes in color, if any, but fracture filling with resin resulted in obvious improvements in apparent clarity.

	DATA DEPOSITORY

Supplementary Photos
	Summer, 2009 @chapter:5


Publication Year: 2021 Title: Multi-Color Sapphires Reportedly from the Garba Tula District, Isiolo County, Kenya Abstract: Figure 1. Color-calibrated photos of sapphires (0.602–7.133 ct) reportedly from the Garba Tula area in the Isiolo region of Kenya. The black arrow indicates the color-change sapphire. Photo by Sasithorn Engniwat.
The Garba Tula sapphire deposit, located in Isiolo County in central Kenya, is a unique igneous gem-corundum producing area. It is a productive source of blue, green, and yellow sapphires (C. Simonet et al., “The Dusi (Garba Tula) sapphire deposit, Central Kenya–A unique Pan-African corundum-bearing monzonite,” Journal of African Earth Sciences, Vol. 38, 2004, pp. 401–410). Figure 1 shows the overall color appearance of 28 Garba Tula sapphires recently examined in this study. They were purchased from a reliable dealer at the Tucson gem shows in 2019. It was noticed that their color varied from dark blue to yellow through various shades of blue and green. Some showed strong yellow and blue zoning, while samples with bluish and greenish color banding were also observed. Interestingly, one of the sapphires exhibited a color-change appearance (indicated by the black arrow in figure 1). Windows were polished into the samples in order to study their internal features and collect chemical data. For some samples, windows were polished parallel to the c-axis for spectroscopic measurements.
The studied materials revealed a slightly higher refractive index (1.761–1.773) than typical metamorphic sapphires. The other standard gemological properties were typical of natural corundum. The vast majority of these Garba Tula sapphires (75%) displayed no fluorescence under long-wave UV radiation, while 18% fluoresced red and the remainder showed zoned orange fluorescence (with very weak red fluorescence or none). The fluorescence intensity to long-wave UV of Garba Tula sapphires is generally very weak to weak. However, they were totally inert to short-wave UV light.

Figure 2. Typical inclusions presented in the sapphires from Garba Tula, Kenya. Left and center: A plane of irregular reflective needles that showed brownish color using fiber-optic lighting and diffused lighting, respectively; field of view 2.88 mm. Right: Numerous single and clusters of zircon crystals, some with tension fractures; field of view 4.8 mm. Photomicrographs by C. Khowpong and S. Wongchacree.
The characteristic inclusions observed from these 28 Garba Tula sapphire samples are presented in figure 2. More than 90% were included with irregular brownish needles and platelets identified by Raman as hematite/ilmenite (Y. Katsurada et al., “Golden sheen sapphire and syenite/monzonite–hosted sapphire from Kenya,” Fall 2018 G&G, pp. 322–323), formed either as planes along the color banding or as a group or cloud. These multiple twinning planes, commonly associated with parallel and/or intersecting growth tubes, were found in more than 80% of the stones. A few samples contained numerous single and scattered clusters identified by Raman spectroscopy as zircon crystals (figure 2, right), sometimes with fine rutile needles and reflective particle clouds, but with fewer irregular brownish platelets. Fingerprint inclusions as well as the other crystal inclusions identified using Raman spectroscopy and the RRUFF reference database, such as apatite and mica, were occasionally observed in the Garba Tula sapphires studied. Moreover, crystals of carbonate minerals were also previously reported in Garba Tula sapphire (Y. Katsurada et al., 2018). However, they typically lack sharp growth structure and milky clouds, as frequently seen in Madagascar and Sri Lanka.
FTIR spectra obtained from the sapphires often showed one or more diagnostic features: a single 3309 cm–1 peak as well as OH-related mineral features such as boehmite, kaolinite, and gibbsite. It was noticed that every sample exhibited a single 3309 cm–1 peak without any subordinate peaks, while the boehmite and kaolinite were observed often (>70%) with a small percentage (18%) showing the gibbsite mineral feature.
Interestingly, the UV-Vis-NIR spectrum of greenish blue to blue sapphires from Garba Tula exhibited a metamorphic-type sapphire spectrum, with strong Fe3+-related absorption features at 377, 388, and 450 nm and also an Fe2+-Ti4+ intervalence charge transfer (A.C. Palke et al., “Geographic origin determination of blue sapphire,” Winter 2019 G&G, pp. 536–579). A broad band centered at 880 nm, which is typically used to indicate basalt-hosted sapphire, was not observed.

LA-ICP-MS showed comparable trace element chemistry profiles between the different color areas of the stones, as presented in table 1. The Garba Tula corundum contains significant amounts of Fe and small amounts of Ti. High Fe content ranging from 1555–3177 ppma and 2121–2943 ppma were detected in greenish blue to blue and yellowish to greenish zones, respectively, while the Ti concentration ranged from 3–41 ppma. The high amounts of Fe were also higher than those of Mogok (Myanmar) and Tunduru (Tanzania) sapphires, which have been previously reported as high-Fe metamorphic sources (W. Soonthorntantikul et al., “An in-depth gemological study of blue sapphires from the Baw Mar mine (Mogok, Myanmar),” GIA Research News, 2017, https://www.gia.edu/gia-news-research/blue-sapphires-baw-mar-mine-mogok-myanmar). Therefore, the chemical composition of the Garba Tula sapphires, particularly their high Fe, is not common for metamorphic sapphire deposits.
The discovery of this source for yellow, green, and blue sapphires could be interesting for the gem trade. The material represents a true challenge for gemologists working on origin determination, as their formation is quite complicated. Although some properties and chemistry of the Garba Tula sapphires are comparable to the corundum xenocrysts originating from alkali basalt fields, their UV-Vis-NIR and FTIR spectra and their internal features are not consistent with typical basalt-related sapphires. The inclusion scene might, in some aspects, overlap between high-Fe metamorphic and basalt-related sapphires. The reflective/iridescent brownish platelets can be seen in metamorphic sapphires from Mogok, Myanmar, as well as in basalt-hosted sapphires from Thailand and Ethiopia. But none of the glassy melt inclusions usually observed in basalt-related sapphires were noticed in the Garba Tula sapphires. One hypothesis is that they formed in the same way as the basalt-related stones but just were not brought to the surface by the basalt. Therefore, a combination of multiple techniques can be useful in the origin determination of sapphires from Garba Tula. @chapter:0