Publish Year: - Title: Morganite Description Abstract: One of the advantages of beryl is its wide color range. These crystals show pastel shades: aquamarine's green and blue and morganite's pink. -photo credit Alan Jobbins.

                      Like many gems found in pegmatites, morganite can form large crystals. Miners in Brazil have found crystals as large as 22 lbs. (10 kg). The Smithsonian Institution in Washington, D.C., includes two faceted gems weighing 236 cts. and 250 cts. in its collection. Although morganite is rarer than aquamarine, large cut stones are readily available on today’s market. That’s probably because morganite hasn’t been promoted to the jewelry-buying public nearly as widely as aquamarine or emerald.

Most of the morganite on the market comes from pegmatite mines in Minas Gerais, Brazil. Afghanistan, Mozambique, Namibia, and the US have been minor and inconsistent sources. While it’s only a minor producer today, the original Madagascar deposit still sets the standard for the best material. That location’s yield of magenta-colored rough was superior to crystals from other sources.

This impressive morganite crystal from the Serra do Urucum mine, Galileia, Minas Gerais, Brazil, is 11 cm high. The faceted stone is 84.88 carats. - Jeff Scovil

This morganite mine is in the Brazilian State of Minas Gerais, near Govenador Valderas. Morganite is usually mined from solidified magma-released fluids called pegmatites. - Eric Welch/GIA. @topic:2


Publish Year: - Title: Tourmaline History and Lore Abstract: This 376.85-carat tourmaline was carved by O. Hansen, using the colors of the tourmaline as part of the design. - Chip Clark, courtesy Smithsonian Institution, National Museum of Natural History

                      Somewhere in Brazil in the 1500s, a Spanish conquistador washed the dirt from a green tourmaline crystal and confused the vibrant gem with emerald. His confusion lived on until scientists recognized tourmaline as a distinct mineral species in the 1800s. The confusion about the stone’s identity is even reflected in its name, which comes from toramalli, which means “mixed gems” in Sinhalese (a language of Sri Lanka).  It’s a term Dutch merchants applied to the multicolored, water-worn pebbles that miners found in the gem gravels of Ceylon (now Sri Lanka).

It’s easy to understand why people so easily confuse tourmaline with other gems: Very few gems match tourmaline’s dazzling range of colors. From rich reds to pastel pinks and peach colors, intense emerald greens to vivid yellows and deep blues, the breadth of this gem’s color range is unrivalled. Brazilian discoveries in the 1980s and 1990s heightened tourmaline’s appeal by bringing intense new hues to the marketplace.

People have probably used tourmaline as a gem for centuries, but until the development of modern mineralogy, they identified it as some other stone (ruby, sapphire, emerald, and so forth) based on its coloring.

One of the earliest reports of tourmaline in California was in 1892. In the late 1800s, tourmaline became known as an American gem through the efforts of Tiffany gemologist George F. Kunz. He wrote about the tourmaline deposits of Maine and California, and praised the stones they produced.

In spite of its American roots, tourmaline’s biggest market at the time was in China.  Much of the pink and red tourmaline from San Diego County in California was shipped to China because the Chinese Dowager Empress Tz'u Hsi was especially fond of the color. There, craftsmen carved the tourmaline into snuff bottles and other pieces to be set in jewelry. San Diego County's famed tourmaline mines include the Tourmaline Queen, Tourmaline King, Stewart, Pala Chief, and Himalaya.

The miners became so dependent on Chinese trade that when the Chinese government collapsed in 1912, the US tourmaline trade also collapsed. The Himalaya mine stopped producing large volumes of gemstones. Other mines in San Diego County, like the Stewart Lithia mine at Pala, still produce sporadic supplies of gem-quality tourmaline.

	The Himalaya mine in Mesa Grande, California, produced this beautiful bicolor tourmaline
	crystal specimen. - Gift of William F. Larson

	The state of Maine has produced beautiful tourmalines. - Courtesy ICA/Courtesy of Boston Findings Co., Inc.

	A mine in California’s San Diego County produced this striking tourmaline. - Courtesy Bill and Jeanne Larson
The supply of tourmaline began to expand during the first half of the twentieth century, when Brazil yielded some large deposits. Then, beginning in the 1950s, additional finds appeared in countries around the world. Madagascar and Afghanistan have produced fine red tourmaline.

	Since the late 1980s, the Paraíba area of Brazil has been known as a source of strikingly intense tourmaline colors, called Paraíba tourmalines. @topic:9


Publish 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 @topic:8


Publish Year: - Title: Tourmaline Description Abstract: The intense green of this chrome tourmaline from Tanzania resembles the color of emerald.

                      Tourmalines come in a wide variety of exciting colors. In fact, tourmaline has one of the widest color ranges of any gem species, occurring in various shades of virtually every hue.

Many tourmaline color varieties have inspired their own trade names:

		Rubellite is a name for pink, red, purplish red, orangy red, or brownish red tourmaline, although some in the trade argue that the term shouldn’t apply to pink tourmaline.

		Indicolite is dark violetish blue, blue, or greenish blue tourmaline.

		Paraíba is an intense violetish blue, greenish blue, or blue tourmaline from the state of Paraíba, Brazil.

		Chrome tourmaline is intense green. In spite of its name, it’s colored mostly by vanadium, the same element that colors many Brazilian and African emeralds.

		Parti-colored tourmaline displays more than one color. One of the most common combinations is green and pink, but many others are possible.

		Watermelon tourmaline is pink in the center and green around the outside. Crystals of this material are typically cut in slices to display this special arrangement.

	The colors displayed by the crystal and fashioned gem are typical of tourmaline with the trade name of rubellite. - Courtesy William F. Larson, Pala International

	Copper is the element that contributes to this Paraíba tourmaline’s highly prized color.

	This attractive slightly brownish, orangy yellow tourmaline is from the Merelani area of Tanzania.

	Some tourmaline crystals display different color zones within a single crystal. - Jeff Scovil
Some tourmalines also show a cat’s-eye effect called chatoyancy. Cat’s-eye tourmalines are most often green, blue, or pink, with an eye that’s softer and more diffused than the eye in fine cat’s-eye chrysoberyl. This is because, in tourmaline, the effect is caused by numerous thin, tube-like inclusions that form naturally during the gem’s growth. The inclusions are larger than the inclusions in cat’s-eye chrysoberyl, so the chatoyancy isn’t as sharp. Like other cat’s-eyes, these stones have to be cut as cabochons to bring out the effect.

A tourmaline’s chemical composition directly influences its physical properties and is responsible for its color. Tourmalines make up a group of closely related mineral species that share the same crystal structure but have different chemical and physical properties. They share the elements silicon, aluminum, and boron, but contain a complex mixture of other elements such as sodium, lithium, calcium, magnesium, manganese, iron, chromium, vanadium, fluorine, and sometimes copper.

Gemologists use a tourmaline’s properties and chemical composition to define its species. The major tourmaline species are elbaite, liddicoatite, dravite, uvite, and schorl.

Most gem tourmalines are elbaites, which are rich in sodium, lithium, aluminum, and sometimes—but very rarely—copper. They occur in granite-containing pegmatites, which are rare igneous rocks. Pegmatites are sometimes rich in exotic elements that are important for the formation of certain gem minerals.  Pegmatites might contain very large crystals up to 1 meter (about 3 feet) in length. Because of the nature of pegmatites, different gem pockets within one pegmatite body can hold tourmaline crystals of very different colors. Or one pocket can produce a variety of differently colored tourmalines. As a result, many mines produce a variety of gem colors.

Another feature of gem pegmatites is the scattered distribution of pockets within them. For miners, working a pegmatite consists mostly of excavating barren rock until the work results in the occasional and sudden reward of a rich pocket full of spectacular gem crystals.

Elbaites offer the widest range of gem-quality tourmaline colors. They can be green, blue, or yellow, pink to red, colorless, or zoned with a combination of colors.

Liddicoatite is rich in calcium, lithium, and aluminum. It also originates in granite-containing pegmatites and offers a diverse array of colors, often in complex internal zoned patterns. It’s named after the late Richard T. Liddicoat, former president of GIA and former chairman of its Board of Governors. He’s often referred to as the “Father of Modern Gemology.”

Uvite is rich in calcium, magnesium, and aluminum. Dravite is rich in sodium, magnesium, and aluminum. Both form in limestone that’s been altered by heat and pressure, resulting in marble that contains accessory minerals like tourmaline.

Some of the most important gem tourmalines are mixtures of dravite and uvite. They’re often brown, yellowish brown, reddish brown, or nearly black in color, but sometimes they contain traces of vanadium, chromium, or both. When present in the right concentrations, these impurities produce rich green hues that rival those of tsavorite garnet and, occasionally, even emerald. Dealers sell these gems as chrome tourmaline, even though they’re not always colored by chromium.

The bright yellow gems some dealers call “savannah” tourmalines are also mixtures of dravite and uvite. Their coloring element is iron.

Schorl is typically black, and rich in iron. It forms in a wide variety of rock types. It’s rarely used as a gem, although it has been featured in mourning jewelry.

Tourmaline’s colors have many different causes. It’s generally agreed that traces of iron, and possibly titanium, induce green and blue colors. Manganese produces reds and pinks, and possibly yellows. Some pink and yellow elbaites might owe their hues to color centers caused by radiation, which can be natural or laboratory-induced. @topic:1


Publish Year: - Title: Topaz Journey Abstract: Few people outside the gem industry realize the true nature of a gemstone’s journey from the mine to the counter of a store. Whether the gem is being offered to consumer’s at a traditional jewelry store’s counter, an internet shopping site, or a television broadcast the journey always involves a great deal of effort.  Tons of earth and countless hours of labor are needed to being a gem from mine to market. @topic:11


Publish Year: - Title: Rose Quartz Description Abstract: The soothing soft pink shades of rose quartz appeal to gem carvers and collectors. – Valerie Power, courtesy Arunashi

                      People accept a certain amount of sand, dirt, and dust as ordinary ingredients in their lives. What they might not be aware of is that those substances are mostly quartz, one of the most common minerals on earth.

	There are many attractive and well-known quartz varieties. The oval gem—fourth from the right—is rose quartz, one of the less abundant gems in the quartz family. – Robert Weldon
Rose quartz is one of the many quartz varieties used as a gem material. It gets its name from its delicate pink color, which ranges from very light (almost white) to medium-dark. The most appealing color typically occurs in larger sizes, and small rose quartz specimens with good color tend to be rare. Rose quartz is always found in massive form, so it lacks regular, flat crystal faces. It’s typically found in pegmatites, but also occurs in hydrothermal veins.

Research has shown that rose quartz owes its delicate pink color to microscopic inclusions of aligned silicate mineral fibers. Advanced testing has shown that they’re generally similar—but not identical—to the mineral dumortierite. The fibers likely crystallized out as the host gem cooled, and they’re aligned according to the crystal directions of the rose quartz.

	Rose quartz contains mineral inclusions that give it a soft pink color. This ring was carved from a single piece of rose quartz. - Eric Welch, courtesy Jana Miyahira-Smith

	Rose quartz beads, cabochons, and rough make an enticing arrangement in a store’s display case. – Robert Weldon
This pastel gem’s inclusions give it a characteristic cloudy translucence, so it’s generally cut into beads and cabochons. Sometimes, the inclusions produce a six-rayed star if the fashioned gem is cabochon-cut and correctly oriented. Fine examples show a distinct, sharp, star floating above even pink bodycolor. The most transparent rose quartz rough might be faceted. Cutters can intensify the delicate color by applying concave facets and cutting gems in larger sizes.

	This star rose quartz is considered fine quality because of its depth of color, degree of transparency, and sharply defined star. – Robert Weldon
The delicate translucence of rose quartz inspires gem carvers to create dainty or whimsical figures. The finest-quality rose quartz rough typically comes from Brazil. Other sources include India, Madagascar, and Sri Lanka.

	This adorable piglet was carved by Gerd Dreher from rose quartz mined in Madagascar. – Robert Weldon
Besides the typical cloudy rose quartz, which is colored by inclusions, there’s a type of transparent quartz that owes its pink color to a different mechanism. Some in the trade call it “pink crystalline quartz,” “crystalline rose quartz,” or simply “pink quartz.” Compared to massive rose quartz, it’s exceptionally rare. It might occur as beautiful clusters of transparent, well-formed crystals. The finest examples are from Brazil, especially a deposit near Galiléia, located near Governador Valadares in the state of Minas Gerais. The best are often left as mineral specimens, which can command high prices at auction. In 2013, a superb example called La Madona Rosa (the Pink Madonna) sold for $662,500. This specimen measures 15.5 x 8 inches (39 x 20 cm) and features a core of smoky quartz that resembles a human form surrounded by a glittering halo of transparent pink quartz crystals.

Material from some of these deposits will fade when exposed to natural light, but its color can be restored by irradiation. Research by Russian crystal growers on synthetic pink quartz has demonstrated a color-causing mechanism, which can cause results very similar to the natural material. Growers produce pink color in transparent synthetic quartz by growing it with impurities of aluminum and phosphorous. Some of these impurities replace silicon in the quartz lattice. Subsequent irradiation produces color centers that give the crystal its pink color. @topic:8


Publish Year: - Title: Peridot History and Lore Abstract: This 146.10-carat peridot is in the collection of the Natural History Museum in London

                      Peridot has always been associated with light. In fact, the Egyptians called it the “gem of the sun.” Some believed that it protected its owner from “terrors of the night,” especially when it was set in gold. Others strung the gems on donkey hair and tied them around their left arms to ward off evil spirits.

The word peridot comes from the Arabic “faridat,” which means “gem.” Most peridot formed deep inside the earth and was delivered to the surface by volcanoes. Some also came to earth in meteorites, but this extraterrestrial peridot is extremely rare, and not likely to be seen in a retail jewelry store.

Early records indicate that the ancient Egyptians mined a beautiful green gem on an island in the Red Sea called Topazios, now known as St. John’s Island or Zabargad. Legend has it that the island was infested with snakes, making mining unpleasant until an enterprising pharaoh drove them into the sea. From the earliest times, people confused this stone—now known to be peridot—with other gems. It was one of many labeled as “topaz.”

Some historians believe that Cleopatra’s famous emerald collection might actually have been peridot. People in medieval times continued to confuse peridot with emerald. For centuries, people believed the fabulous 200-ct. gems adorning the shrine of the Three Holy Kings in Germany’s Cologne Cathedral were emeralds. They are, in fact, peridots. @topic:2


Publish Year: - Title: Peridot Description Abstract: While the 64.57-carat cut peridot is magnificent, it is overshadowed by the amazing 7.9-cm tall crystal. Both are from Sappat, Kohistan, Pakistan. - Jeffrey Scovil

                      Gem miners find peridot as irregular nodules (rounded rocks with peridot crystals inside) in some lava flows in the United States, China, and Vietnam and, very rarely, as large crystals lining veins or pockets in certain types of solidified molten rock. Sources for the latter include Finland, Pakistan, Myanmar, and the island of Zabargad.

	This incredible suite of peridot jewelry has a total weight of 350.40 carats. All are top-quality peridots from Pakistan. - © GIA & Harold & Erica Van Pelt
Geologists believe both types of deposits relate to the spreading of the sea floor that occurs when the earth’s crust splits, and rocks from its mantle are pushed up to the surface. Sometimes—as in Myanmar— these rocks can be altered, deformed, and incorporated into mountain ranges by later earth movements.

Rarely, peridot can have an extraterrestrial source, being contained in meteorites that have fallen to earth.

The color range for peridot is narrow, from a brown-green color to yellowish green to pure green. Yellowish green is the most common peridot color seen in jewelry.

	Peridot is best known for its yellowish green color.
Peridot is the gem variety of the mineral olivine. Its chemical composition includes iron and magnesium, and iron is the cause of its attractive yellowish green colors. The gem often occurs in volcanic rocks called basalts, which are rich in these two elements.

	These peridots from Peridot Mesa in the San Carlos Apache Nation, Arizona, are set in a jewelry style called "Healing Sisters.” - Courtesy Apache Gems @topic:2


Publish Year: - Title: Lapis Lazuli Description Abstract: Lapis lazuli is an aggregate of several minerals. Lazurite grains provide its characteristic blue color, while golden flakes of pyrite can add attractive contrast.

                      Lapis lazuli is a rock, which means it’s an aggregate of several minerals. This ancient gem contains three minerals in varying amounts: lazurite, calcite, and pyrite. Sometimes, it also contains one or more of the following: diopside, amphibole, feldspar, and mica.

	Lapis lazuli is an aggregate of several minerals. Lazurite grains provide its characteristic color. The higher the percentage of lazurite grains in the aggregate, the darker the blue color. - John Koivula
Lapis frequently contains varying amounts of whitish calcite matrix—the host rock that surrounds the gem—or flecks or veins of glinting yellow pyrite, or both. The gem can also have a smoothly uniform bodycolor, free of visible pyrite and calcite.

	Calcite shows up as white flecks or streaks in the aggregate.

	The golden, metallic-looking spots in lapis are pyrite. - Robert Weldon, courtesy Gary Bowersox
Lapis is semitranslucent to opaque, with a waxy to vitreous luster. It has fair toughness, and its hardness ranges from 5 to 6 on the Mohs scale, depending on the mix of minerals.

Variously described as indigo, royal, midnight, or marine blue, lapis lazuli’s signature hue is slightly greenish blue to violetish blue, medium to dark in tone, and highly saturated. In its most-prized form, lapis lazuli has no visible calcite, although it might have gold-colored pyrite flecks. If the flecks are small and sprinkled attractively throughout the gem, their presence doesn’t necessarily lower lapis lazuli’s value. The lowest-quality lapis looks dull and green, the result of an excess of pyrite. Lapis with white calcite streaks is less valuable.

	The calcite matrix in this cabochon will lower its appeal to most buyers. - Robert Weldon
Although many people associate lapis with dark blue, it’s also found in other shades of blue, and even other hues. Its color can range from deep violet blue and royal blue to light blue to turquoise blue to a greenish blue. The combination of different minerals in the aggregate determines the color. For example, lazurite is responsible for producing royal blue lapis, while a mineral called afghanite creates a pale blue shade.

	This striking freeform carving displays a lovely shade of blue along with attractive golden pyrite accents. - Robert Weldon, courtesy Gary Bowersox
Worldwide, lapis is mined in several areas. The traditional source of the finest lapis lazuli is the same today as it was thousands of years ago—the mountains of Afghanistan. Other major sources are Chile and Lake Baikal in Siberia, Russia. Minor sources are Angola, Canada, Colorado (US), and Pakistan.

	Afghanistan is the world’s major source of lapis lazuli as well as the major source of the gem’s best color. - Dr. Edward J. Gubelin @topic:1


Publish Year: - Title: Ametrine History and Lore Abstract: Concave facets on the pavilion contribute to the striking look of this 27.50-ct. ametrine. Creative gem cutters sometimes use concave facets to give a gem a dramatic appearance. Photo by Robert Weldon/GIA, courtesy Minerales y Metales del Oriente.

                      The world’s only commercial source of ametrine is the Anahi mine in southeastern Bolivia. Legend has it that a Spanish conquistador discovered the mine’s location in the 1600s and introduced the gem to Europeans when he presented several specimens to his queen. The mine had been given to him as a dowry when he married a native princess named Anahi. After that, the mine was lost for more than three centuries. Rediscovered in the 1960s, the mine’s ametrine began appearing on the market again during the 1970s. Today the mine, named Anahi for the legendary princess, also produces natural amethyst and citrine.

	The mine, located near the center of the photo, is barely visible through the foliage between the two mountains. Photo by Robert Weldon/GIA.
The mine area is remote. Travel to and from the mine is limited to a flight in a small airplane or by a combination of roads and boats. Some supplies and personnel travel to and from the mine by air. Supplies and mine production move by boat. It’s not hard to imagine why the mine’s location was lost for centuries.

	A clearing near the mine has space for only a small airplane. Photo by Robert Weldon/GIA.

	A miner pushes a cart full of waste material in the depths of Bolivia’s Anahi ametrine mine. Photo by Robert Weldon/GIA. @topic:1


Publish Year: - Title: Ametrine Description Abstract: This amazing ametrine trilliant cut features a multitude of facets to create internal reflections that blend the amethyst and citrine colors. Photo by Robert Weldon/GIA, courtesy Minerales y Metales del Oriente, Bolivia, SA.

                      Transparent, bicolored quartz with the colors of both amethyst and citrine in the same gem is called ametrine or amethyst-citrine. The contrasting colors give it an intriguing appearance.

Fine ametrine shows medium dark to moderately strong orange, and vivid to strong purple or violetish purple. Larger gems, usually those over 5 carats, tend to show the most intensely saturated hues. Dealers look for an attractive half-and-half distribution of each color, with a sharp boundary between the two colors at the center of the fashioned gemstone.

Ametrine is often cut as a rectangular step cut because that style nicely displays the bicolor effect. Cutters try to emphasize both colors equally.

	Rectangular step cuts clearly show off the striking bicolor nature of these ametrines. Photo by Maha Tannous/GIA.
Cutters  sometimes fashion ametrines as mixed cuts or brilliant cuts and use internal reflections to mingle the amethyst and citrine colors. Ametrine is also popular in free-form or fantasy cuts.

Ametrine is a form of quartz in which the colors of the amethyst and citrine quartz varieties are present in the same crystal. Photo by Robert Weldon/GIA, courtesy Minerales y Metales del Oriente, Bolivia, SA.

	A unique display of ametrine’s colors blends and contrasts in this fantasy cut by noted gem designer John Dyer. He named his creation Ametrine SunRay ™. Photo by Lydia Dyer, © John Dyer & Co., gem courtesy John Dyer & Co.
There’s only one commercial source of natural ametrine: a deposit in eastern Bolivia, close to the Brazilian border. Legend has it that a Spanish conquistador discovered the location in the 1600s, but it was lost for more than three centuries. Ametrine began appearing on the market again during the 1970s. The mine, the Anahi, also produces natural amethyst and citrine.

	The Anahi mine in eastern Bolivia is the source of these rough ametrine crystals. Photo by Robert Weldon/GIA, courtesy Bart Curren. @topic:1


Publish Year: - Title: Amethyst Description Abstract: This amethyst crystal is from Namibia. It shows classic quartz crystal shape: a six-sided columnar crystal with a pyramid-shaped termination at the top. Courtesy Daniel Trinchillo, Fine Minerals International.

                      Amethyst is the purple variety of the quartz mineral species. It’s the gem that’s most commonly associated with the color purple, even though there are other purple gems such as sapphire and tanzanite. Its purple color can be cool and bluish, or a reddish purple that’s sometimes referred to as “raspberry.”

	Most people think of amethyst when they picture a beautiful purple gem. Courtesy Intimate Gems.
Amethyst’s purple color can range from a light lilac to a deep, intense royal purple, and from brownish to vivid. Amethyst also commonly shows what is called color zoning, which in the case of amethyst usually consists of angular zones of darker to lighter color.

	Amethyst commonly shows zones of darker and lighter colors. Photo by Mike Havstad/GIA. @topic:1


Publish Year: 2019 Title: Tucson 2019 Overview Abstract: Buyers browse the selection of goods available at the 2019 AGTA GemFair in Tucson. Photo courtesy of AGTA.
The 2019 gem shows came to Tucson with a wealth of material, both new and old, as eager buyers descended on exhibitors to take in the latest trends. While traffic was not as heavy as in recent years, several vendors noticed an influx of young people looking for natural, untreated gemstones. Spectacular color in gems and stunning jewelry designs were on view, while many pointed to sustainable and ethical practices as a major consideration in their colored gemstone and jewelry purchases.

	Overview of gemstone supply and demand

The Asian market has slowed, according to Edward Boehm of RareSource (Chattanooga, Tennessee), and as a result, gems that have been popular in Asia, particularly China, are starting to gain traction in the United States. Boehm indicated that the growth of the Asian market is still driving production in African countries, particularly Nigeria, and Americans are the primary consumer of this increased production. Improving exchange rates have also worked in the American market’s favor. Dave Bindra (B&B Fine Gems, Los Angeles) said that while higher-end gemstones are still difficult to come by, they are as much in demand as ever. Commercial-grade gems, Bindra noted, have become more accessible. Like Boehm, he attributes this in large part to activity in the Chinese market in recent years. Shahin Aboosalih of SR Trading’s Hong Kong office talked to us about material that remains popular in the Chinese and Japanese markets.

Left: Opals like “The Chief,” a 14.41 ct Australian black specimen, were in demand this year. Photo by Kevin Schumacher, courtesy of 100% Natural Ltd. Center: Fancy-color sapphires, including this 50.08 ct color-change gem, were also popular. Photo by Robert Weldon/GIA, courtesy of Edward Boehm. Right: The secondary market is an excellent source for material, such as this 115.13 ct golden sapphire. Photo by Kevin Schumacher, courtesy of B&B Fine Gems.
Opal, particularly black opal, has seen a resurgence among high-end jewelers. Boehm believes there could be a growing appreciation for the gem due to the discovery of opal in Ethiopia, which has brought opal to different price points and different audiences in the past decade. Rod Griffin (Rod Griffin Boulder Opals) discussed his experiences in Australian opal mining and the new technology he is using to exploit deposits once thought to be depleted.
Color, of course, continues to reign, and dealers are seeing what Boehm called “an increased appreciation for the unusual.” Beyond the classic “Big Three,” vendors stocked gemstones such as sphene, grandidierite, and various colors of sapphire. Color-change stones seen in previous shows, such as pyrope garnet and alexandrites, were also on display and drawing new attention. Cutters, he noted, are making strides in recognizing and using to different effect specific phenomena in gemstones, such as the trichroism of tanzanite. Spinel remains the most popular “new” gem, according to Boehm, especially in nontraditional colors such as lavender and violet, which would have been cut too dark (or not at all) in the past. Gray spinel in particular made a splash at this year’s show, with several exhibitors stocking the material in a variety of cuts.
Brian Cook of Nature’s Geometry (Tucson) noticed a cross-pollination between the mineral and jewelry industries, with more designers and jewelers using raw euhedral stones to create unique looks. He also noted that several new mineral shows, developed out of dealers’ collectives rather than sponsored by one promoter, have come to the city and seem to be here to stay. The popularity of the Granada Gallery, which prides itself on its dedication to “fine natural design,” is one such indicator.
American gemstones were also in heavy rotation at the shows. Eric Braunwart of Columbia Gem House, who has long stocked American production in his inventory, said that sales of these products were good. Designer Derek Katzenbach discussed his use of American gemstones such as Maine tourmaline. And among the material seen was Montana sapphire, nephrite from Washington State, Oregon sunstone, and hyalite opals from Oregon.
Bindra noted that many of his company’s rare gems came out of the ground 20–30 years ago, and that he relies heavily on the secondary market to procure such material. In this way, he is able to provide his clients with the high-end material they have come to expect. This sentiment was echoed by Jared Holstein of Perpetuum Jewels, a wholesaler working with antique diamonds and colored stones in historical cuts for the bridal market. Holstein also finds the secondary market to be a good way to source gemstones in an ethical and environmentally sustainable fashion.
Responsibly sourced material continues to be heavily sought after. Braunwart said this might have been his most successful show in his 41 years at Tucson. He credits this in large part to his commitment to providing fair trade, responsibly sourced gemstones. Susi Smither, who founded The Rock Hound specifically to create an ethical jewelry line, delighted in showing us her Molten Muzo collection, which used responsibly sourced Colombian emeralds and recycled gold. And gem dealer and jewelry designer Roger Dery told us about Gem Legacy, the nonprofit he founded to benefit East African mining communities.
We hope you enjoy our coverage of the 2019 Tucson gem shows!
The following contributed to this report: Erin Hogarth, Tao Hsu, Jonathan Muyal, Lisa Neely, Aaron Palke, Duncan Pay, Albert Salvato, Kevin Schumacher, Jennifer Stone-Sundberg, Wim Vertriest, and Robert Weldon.

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An Inside Look at the 2019 Tucson Shows @topic:11


Publish Year: - Title: Winter 2019 G&G: Geographic Origin Special Issue Abstract: The Winter 2019 edition of Gems & Gemology is devoted to the determination of geographic origin for specific colored gemstones. This issue hopes to promote a healthy discussion about this complex subject, and bring greater transparency on the testing methods and criteria utilized in GIA’s laboratories.
The Geographic Origin Dilemma
Shane McClure and co-authors introduce the many facets of geographic origin determination. The authors explain that in order to adequately issue geographic origin reports, a laboratory must meet three requirements: scientific instrumentation, experienced gemologists, and a comprehensive collection of reference samples of known provenance.
Geology of Corundum and Emerald Gem Deposits: A Review
Similar geologic environments can produce gems with similar gemological properties, making it difficult to connect the properties of individual gems to the geology of their deposits. Gaston Giuliani and Lee Groat review the classification systems of corundum and emerald deposits, and discuss how genetic models can give geologic and geographic clues on their origins.
Field Gemology: Building a Research Collection and Understanding the Development of Gem Deposits
Wim Vertriest, Aaron Palke, and Nathan Renfro discuss the importance of building a reliable reference collection of known provenance in order to support geographic origin determination. Since gem-producing areas are constantly changing, field gemologists play a critical role in documenting the global mining and trading environment and the development of gemstone enhancement procedures.
A Review of Analytical Methods Used in Geographic Origin Determination of Gemstones
Origin determination is possible because there is a close relationship between the geology of an area and the properties of gemstones found there. Groat and co-authors take an in-depth look at the analytical techniques commonly used to characterize gemstones.
Geographic Origin of Specific Gemstones
In some cases, the value of a gemstone depends strongly on its geographic origin. Careful analysis of inclusions, trace element chemistry, and spectroscopic data often lead to conclusive origin determination. However, there are instances where the overlap in data is too great and laboratories are unable to make the call. Each article in this series—blue sapphire, ruby, emerald, Paraíba tourmaline, and alexandrite—outlines GIA’s methods and criteria for establishing geographic origin of that particular gemstone.
What’s Next?
What does the future hold for the geographic origin service? Could non-industry instrumentation and techniques be adapted to gemstone applications in order to improve consistency? McClure and co-authors explore whether developing a service for additional gemstones carries enough value to justify the expense. @topic:2


Publish Year: 2014 Title: Varieties of Rutilated Quartz – Tucson 2014 Abstract: Figure 1. This 85 ct quartz crystal contains bright reddish rutile needles. Photo by Robert Weldon; courtesy of Rare Earth Mining Co.

              Rutilated quartz has come into its own as a mainstream gem material, thanks in part to its seemingly infinite variety and one-of-a-kind appeal for jewelry designers. Reddish rutile, owing its color to traces of iron, was exhibited at the AGTA show by Rare Earth Mining Co. (Trumbull, Connecticut). Rare Earth CEO Bill Heher said the material was recovered from Bahia in northern Brazil some decades ago before the mine closed. But due to the rising value of rutilated quartz, the deposit has been reopened and worked in recent years. The distinctiveness of the material, in this case an 85 ct gem (figure 1), lies in its relative transparency and bright reddish color—which can be matched or contrasted in jewelry.

Golden and copper-color rutile is traditionally seen in quartz, and connoisseurs are always on the lookout for a six-rayed star pattern of rutile. Though such stars occur regularly in the rock crystal, they are rarely oriented in such a way to be easily cut into a faceted or cabochon gem. Strong, isolated rutile stars located in the rough must be painstakingly oriented to be visible face-forward, as in the 34.55 ct gem (figure 2) cut by Falk Burger (Hard Works, Tucson). At the center of the star, an additional inclusion of hematite is visible.

	Figure 2. This 34.55 ct quartz has been cut to display the star-shaped needle formation. Photo by Robert Weldon; courtesy of Hard Works.

	Figure 3. This 209.06 ct quartz features a rose-shaped cluster of inclusions. Photo by Robert Weldon; courtesy of Hard Works.
Burger said that rutile can take unusual forms as well. Minute gray rutile needles in the top of the quartz in figure 3 are clustered in the shape of a rose. The quartz also contains layers of pink and greenish chlorite phantoms. The quartz itself weighs 209.06 ct, and was fashioned by Burger to best exhibit the rutile rose. @topic:3


Publish Year: 2016 Title: Update on Colored Gemstone Mining in Tanzania Abstract: Figure 1. A view of the pink sapphire mining pit at Kibuko, in the Uluguru Mountains of Tanzania. Photo by Vincent Pardieu/GIA.

	A team of GIA field gemologists visited Tanzanian mines in the summer of 2016 to collect ruby and sapphire for GIA’s reference collection and explore new sources of colored stones. The field expedition, led by these authors, visited many known Tanzanian gem localities as well as new deposits at Loolera, Kibuko (figure 1), Lutela, Amani Makoro, and Ngapa. The trip was made possible by the support of Mark Saul of Swala Gem Traders (Arusha, Tanzania), Tanzanian gem broker Justin Mmbaga, and several regional mining officers. We found that the most active colored gemstone mining area is still Merelani, which produces tanzanite and green grossular garnet. Ruby and sapphire output has been relatively low since the 2009 discovery of the ruby deposit in Montepuez, Mozambique, as confirmed by our Tanzanian sources.

	Tanzanian miners supply stones to licensed brokers, who are allowed to buy and transport gems within the country. These brokers sell to licensed master dealers, who are allowed to export internationally. These master dealers are mainly located in Dar es Salaam and Arusha. While we met Thai and Sri Lankan buyers in Mahenge, Songea, and Tunduru, foreigners must have approval from regional mining officers and possess a proper business visa to visit the deposits. This is particularly enforced in southern Tanzania; around Songea, we met immigration officers who were “hunting for foreigners.”

	Our journey started in Longido, where rubies were discovered about 100 years ago (D. Dirlam et al., “Gem wealth of Tanzania,” Summer 1992 G&G, pp. 80−102). The main operation in the Longido area is the Mundarara ruby mine, currently Tanzania’s largest, with a workforce of 78 people. The gems are extracted from an underground tunnel about 200 meters deep crossed by several horizontal tunnels that host most of the production. The mine yields ruby in zoisite (suitable for carving), as well as some cabochon- and facet-grade material of a very deep red color. The color is reminiscent of rubies from Mozambique.

	We continued to the Umba River, where Tanzanian sapphire production began after World War II and a ruby-bearing area was discovered by Georges “Papas” Papaeliopoulos in the 1950s (again, see Dirlam et al., 1992). The situation has changed significantly since author VP visited in 2005 and 2009. At the time there was a dispute between the company working the deposit, called “Amazon,” and local communities. The dispute ended with the government revoking Amazon’s license. During our 2016 expedition, we witnessed about 40 small-scale local miners using hand tools to work the primary deposit discovered by Papaeliopoulos, as well as secondary deposits scattered along the banks of the Umba. Most of the production is traded each evening around the Mississippi Hotel in Umba.

	In the Kilindi area, about halfway between Umba and Winza, a new ruby deposit has been discovered near the Maasai village of Loolera. This site, located atop a hill, produces gems very similar to those found near Winza in 2007. We visited the area with the support of the village leader, who said the first rubies were found about 10 years ago, but the quality of the stones was low. A few miners were working the deposit sporadically using hand tools. But in April 2016, some good-quality material was found in amphibole matrix, attracting considerable interest. About 25 mining licenses were issued during the summer of 2016, but there is a sense that the area is under the control of a few major players.

	The deposit where the first rubies at Loolera were found is owned by a miner called Dr. Ozu. The mining pit appeared to be about 90 meters deep, but we could not inspect the tunnel as Dr. Ozu was not present. We studied the entrance and looked through the tailings near the pit. In these rejects we found many small fragments of rubies associated with garnets, amphibole, mica, and feldspar. Although the material we saw resembled Winza ruby, the stones contained minute particles that gave them a milky aspect.

	Our next stop was Winza, where an important gem rush occurred in 2007−2008 (D. Schwarz et al., “Rubies and sapphires from Winza, central Tanzania,” Winter 2008 G&G, pp. 322−347; V. Pardieu, “The Winza ruby and sapphire mining area, Mpwapwa district, Dodoma province, Tanzania,” www.fieldgemology.org, 2009). The main mining area at Mtakanini was nearly deserted. An old rusted washing plant was visible, but due to mechanical problems it had not washed any stones in more than a year. We estimated that a handful of people were still mining around Mtakanini, mainly at primary deposits in underground tunnels, some of which were over 100 meters deep. Working conditions are difficult, as the rock is hard and the tunnels are prone to flooding. We learned that several brief ruby rushes occurred nearby at Godegode, Makutop, Magaseni, Singonali, and Berega. In Morogoro Province, two ruby and spinel mining areas have been exploited since the 1980s. One is located just east of Morogoro in the Uluguru Mountains, and the second is about 150 km south near Mahenge. Most of the gem trade in the Uluguru Mountain region is in Mkuyuni, while the mining takes place near Matombo, Ngongolo, Mwaraze, and Kibuko. In Matombo we witnessed about 30 people retrieving pink spinel and rubies from a secondary deposit near Kiswila. Near Ngongolo, we visited four small-scale operations where locals with hand tools were mining small rubies in marble associated with pyrite, graphite, and mica.

	Near Kibuko, a new pink sapphire deposit was worked by about 10 miners on a site owned by Luciano Kipanzi, who took over the area in 2015. Pink sapphires up to 100 carats are associated with carbonates and pyrite in a primary deposit (figure 2). Most of the stones were the milky “geuda” type, but there was some transparent facet-grade material with very fine crystallization. The mine had evidently yielded about 20 kg of sapphire, from cabochon- to facet-grade, during the previous six months. Nearby, three groups of small-scale miners were uncovering a limited amount of similar stones from secondary deposits.

Figure 2. Pink sapphires from the new deposit near Kibuko. Photo by Vincent Pardieu/GIA.

	The Mahenge district, known for spinel and ruby, is the second most active gemstone mining area in Tanzania. Recent discoveries of graphite near Ipanko and garnet near Lutela (the latter in February 2016) have kindled interest in the area. The new alluvial deposit produces an interesting range of attractive garnets (figure 3), from light “champagne” to deeper saturated rhodolite, including some color-shifting stones. We saw some clean stones weighing up to 20 ct and heard about others as large as 60 ct. About 100 miners were still working the alluvial deposit. Activity was already slowing; we were told that a few months earlier, up to 300 miners were in the valley. This secondary deposit is rapidly depleting, and so far no primary deposit has been located.

Figure 3. This garnet was mined from the new deposit in Lutela, Tanzania. Photo by Vincent Pardieu/GIA.

	Ipanko is still the main spinel deposit in the region. Author VP noticed that the pits were much larger than in 2012, meaning that the area had been mined since then. Nevertheless, the activity seemed slow compared to 2012: Several excavators were working secondary deposits, whereas small-scale miners once worked individual plots, called “boxes” by the locals. The nearby primary spinel deposit was still active, with about 400 people mining red spinel and only a few working on rubies. We then visited several small-scale ruby deposits along the Lukande River, including three operations working either primary or secondary deposits. As in the Uluguru Mountains, the rubies from these areas come from marble-type deposits. We saw about 50 miners working around Lukande, Kwam Somali, Mayote, Chipa, Ibogoma, Gombe, and Kitonga during the dry season, retrieving cabochon-grade rubies along with smaller facet-grade material. During the rainy season, these workers focus on gold mining or farming.

	Our last visit was the region around Songea and Tunduru, where sapphire production began in the 1990s. The Songea deposit, discovered in 1992, was quite productive until the discovery of fine blue, yellow, and pink sapphires near Tunduru in 1994. The deposit was nearly inactive until the early 2000s, when the newly developed beryllium diffusion treatment was able to turn Songea’s muddy green and brownish purple stones into attractive yellow to orange sapphires. In Songea, we heard of a new discovery at Amani Makoro, close to the old diggings around Ngembambili and Masuguru. In Amani Makoro, we witnessed about 200 miners in a swampy area using hand tools. The aspect and quality of the stones was similar to those from Ngembambili and Masuguru. Overall, about 300 people are still mining or trading gems around Songea. According to the regional mining officer, nine Thai merchants are registered buyers here. Songea still seems to be Tanzania’s most active sapphire mining area.

	The region east of Tunduru, located along the Muhuwesi, Lumesule, and Ruvuma rivers and up through Ngapa and Kitowelo, is known to produce blue, yellow, green, pink, and purple sapphires, and rarely rubies. The deposits, discovered by Swiss gem merchant Werner Spaltenstein in 1994, were very active until 1999, when buyers left Tunduru for the newly discovered sapphire deposits of Ilakaka, Madagascar.

	A paved road linking Tunduru to the coast and then Songea should be finished in 2017, making these areas much less isolated. Around Tunduru, a new environmental law that forbids mining within 60 meters of a stream or a river is creating issues, as most of the mining there takes place in riverbeds. Last year Mr. Spaltenstein had to stop his mechanized operation because of that law, though local authorities seem to be more tolerant of small-scale miners. While the area is much less active than when VP visited in 2005 and 2008, we estimate that about 400 to 500 miners are working around Tunduru. In the town, we found 10 Sri Lankan and three Thai buying offices. In the main gem-producing area there was a small rush in Ngapa, near Kitowelo and the area known as the “DSM Box” (figure 4). We were told the area produces some good blue, pink, and purple sapphire rough weighing up to 50 ct; fine sapphire of this size was previously unknown in Tunduru. The second most active place was Muhuwesi, where several groups of small-scale miners are reportedly working.

Figure 4. This blue sapphire rough, weighing about 7 ct, is from the new deposit at Ngapa, near Tunduru. Photo by Vincent Pardieu/GIA.

	The post-2009 downturn of Tanzania’s ruby and sapphire mining was not unexpected, because many of the corundum discoveries triggered rushes that were exploited for short-term gain. Tanzania also faces competition from the world-class ruby deposit in Montepuez. Nevertheless, recent colored stone discoveries point to the vast potential of gem mining in Tanzania. @topic:9


Publish Year: 2016 Title: Tourmaline Termination Abstract: Figure 1. Highlighted by blue and pink color accents, trigonal growth features are clearly visible on the surface of this 42.78 ct polished tourmaline termination. Photo by Kevin Schumacher.

	Depending on their size, large tourmaline crystals are known as “hand” or “cabinet” mineral specimens. To be used in jewelry, specimens of sufficient quality must be cut to a suitable size. This generally results in all of the natural surfaces being ground off and polished away. On occasion, however, a natural surface on a crystal is so interesting that it is preserved and used as a gem in its own right. Such was the case with a blue cap elbaite tourmaline (figure 1) from Fianarantsoa, Madagascar.

	During the cutting of this tourmaline, gem artist Falk Burger (Hard Works, Tucson, Arizona) saved the blue cap termination by sawing it off into a thin plate and mirror-polishing the sawn surface, thereby accentuating its remarkable trigonal growth features and pink and blue color zoning (figure 2, left). This resulted in the beautiful and unique designer gem seen in figure 1, which weighed 42.78 ct and measured 37.23 × 31.97 × 3.60 mm.

	Figure 2. Left: Using diffused transmitted light, contrasting pink and blue color zoning is seen. Right: Viewing the tourmaline through crossed polarizers and looking perpendicular to the polished plate, interference colors were clearly visible. Photomicrographs by Nathan Renfro; field of view 23.95 mm.

	This gem was also very interesting when examined through a microscope (figure 2, right). In crossed polarizers, while looking perpendicular to the polished plate, interference colors were clearly visible, accentuating the growth of the tourmaline. @topic:9


Publish Year: 2016 Title: Imperial Flame Topaz Sculpture Abstract: Figure 1. The Imperial Flame, a magnificent natural-color Brazilian topaz, was cut from a 615 ct crystal recovered some 20 years ago. The finished 89.53 × 20.56 × 19.15 mm sculpture weighs 332.24 ct. Photo courtesy of Sonja Kreis Unique Jewelry.

	One of the 2016 Tucson show’s most noteworthy gems was a 332.24 ct freeform Imperial topaz (figure 1) at the GJX booth of gem cutter Alexander Kreis (Sonja Kreis Unique Jewelry, Niederworresbach, Germany). Topaz with this red, pink, or orangy yellow color component is rare and highly sought after in the trade. Named the “Imperial Flame” by the Kreis family, the crystal was reportedly recovered from Brazil’s Ouro Preto topaz mines two decades ago. Topaz has been known from this area of Minas Gerais since 1768 (P.C. Keller, “The Capão topaz deposit, Ouro Preto, Minas Gerais, Brazil,” Spring 1983 G&G, pp. 12–20).

	Although mining was extensive at Ouro Preto in the mid-1990s (D.A. Sauer et al., “An update on Imperial topaz from the Capão mine, Minas Gerais, Brazil,” Winter 1996 G&G, pp. 232–241), the Kreis family confirmed that there is currently no large-scale mining. They visited the area after a collector informed them of a 615 ct crystal with exceptional color and clarity (figure 2). According to their contact, the crystal is “old production” mined at least 20 years ago. After analyzing the rough over a period of four months, the family purchased it in December 2015 with the objective of cutting the largest, highest-quality Imperial topaz known.

Figure 2. The original 615 ct Imperial topaz crystal from which Alexander Kreis fashioned the 332.24 ct Imperial Flame. Photo courtesy of Sonja Kreis Unique Jewelry.

	Due to the gem’s perfect basal cleavage, cutters must avoid grinding the stone perpendicular to the cleavage plane, while also accounting for inclusions that might cause the stone to break on the wheel. According to Sauer et al. (1996), well-formed, largely inclusion-free crystals typically yield up to 2 ct per gram (5 ct), which is a 40% recovery rate. Cutting the Imperial Flame took approximately eight days, spread over a period of 3–4 weeks, to allow Kreis to make trial carvings with smaller Imperial topaz pieces to test his cutting concepts. The cutting process began with sawing off the included portions and grinding to shape the solid crystal (figure 3), followed by faceting and carving to produce the reflective, grooved surfaces. The fashioning process yielded a spectacular gem measuring 89.53 × 20.56 × 19.15 mm. At 332.24 ct, it had a finished yield of 54%.

Figure 3. After trimming away included portions of the crystal’s base, Alexander Kreis gently removes any surface-reaching inclusions and begins to shape the crystal to his own unique design. Photo courtesy of Sonja Kreis Unique Jewelry.

	Intended as an arresting gem sculpture for a connoisseur or high-end collector, the piece is for sale. @topic:2


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

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

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

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


Publish Year: 2017 Title: Ethical and Sustainable Vertical Integration in the Sapphire Market Abstract: Untreated yellow sapphires such as this 12.18 ct gem command a premium in the marketplace, especially when a transparent chain of custody and sustainable mining practices can be documented for the customer. Photo by Eric Welch/GIA, courtesy of Sheahan Stephen Sapphires.

	When the recession of 2008 struck, Sheahan Stephen (Sheahan Stephen Sapphires, Inc., San Francisco, California) had been dealing in Sri Lankan gemstones for two years. He saw his monthly cash flow drop to a third of what it had been when he first started traveling to Sri Lanka to buy stones for resale in the United States. During the recession he decided to borrow money and become vertically integrated. Stephen created a transparent supply chain and an ethical supply model by becoming directly involved in mining. His new business also included heat treatment, cutting, and sales.

	Sustainable practices tie directly into Stephen’s beliefs in how businesses should strive to operate. He sees lack of sustainability as a major cause of many of society’s problems. He works with his customers in what he calls “customized” vertical integration. He fills specific orders for his customers directly from mines and brings the sapphires to market in a controlled manner, meaning they are always in his hands or an employee’s hands until they reach the final customer. Stephen guarantees the entire supply chain and strives to provide full documentation, including the mine the sapphires (see above) came from and the name of the treater and the cutter.

	He focuses on education and training in Sri Lanka to obtain the quality and traceability his customers expect. Training and complete trust in his Sri Lankan staff allow him to buy stones unseen that will fill his customers’ specifications. Stephen also believes in providing education and other assistance for his employees’ families in Sri Lanka.

	Stephen finds that customers today want more information about their jewelry. They want to know where a piece came from, who was involved in manufacturing it and bringing it to market, and the corporate social responsibility practices of the company involved. With many of his customers today willing to pay 30% more for documented ethical sapphires and sapphire jewelry, he focuses on growing his sales with sustainability-minded clients. At the same time, he strives to be close to other wholesalers in his pricing to stay competitive and grow his business.

	A major part of his business investment is the time he spends growing relationships with miners and cutters in Sri Lanka that can take years. That is an essential element of developing a sustainable business model for artisanal mining. Stephen hopes that building long-term relationships with his employees and suppliers in Sri Lanka and perfecting the processes throughout the supply chain will allow for slow but sustainable business growth. His vision is to take this model to other gem mining countries, especially in Africa, where he is currently working in Madagascar. @topic:12


Publish Year: 2017 Title: An Inside Look at the 2017 Tucson Shows Abstract: A 59.28 ct quartz with iron staining. Photo by Robert Weldon/GIA, courtesy of Rare Earth Mining Co.

The 2017 Tucson gem and mineral shows drew eager buyers from all over the globe. Although many dealers reported lower traffic this year, most were content with the volume of business and noted that buyers were “serious.”

As in previous years, we identified some strong trends:

Demand for special one-of-a-kind pieces in both pearls and colored gemstones
Continuing investment by multinational companies in colored gemstone mining and distribution
A growing focus on ethically sourced gemstones and beneficiation
Strong demand for high-end gems and a softening of demand for commercial goods
Continuing importance of the secondary market in the U.S. for exceptional pieces
Innovative partnerships emerging between individual colored gemstone mines, designer cutters, and television merchandisers

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An Inside Look at the 2017 Tucson Shows
This year’s big story was the emergence of Ethiopia as a potentially major source of gem-quality emerald. These new gems resemble other schist-hosted emeralds, especially those from Brazil and Zambia. Although most of the material is less saturated and included, dealers are excited that the new source also produces fine gem-grade crystals of exceptional size, color, and clarity.

Dealers also talked about the October 2016 removal of U.S. sanctions on Myanmar, legalizing the import of Burmese jadeite and rubies. According to Edward Boehm of RareSource, the lifting of the ban was widely welcomed, but Myanmar government reforms of the gem mining sector have some way to go. Conditions on the ground are much improved, however. Boehm told us new production might take some time to appear, which would impact prices and selection of available goods in the short term.

Large multinational companies have significantly impacted colored gemstone mining and distribution over the last decade. Gemfields’ Kagem and Montepuez mines supply approximately one-third of global emerald and 70% of global ruby production, respectively. At this year’s show we were able to interview Gemfields CEO Ian Harebottle for his perspective on the company’s operations and its 2013 merger with luxury brand Fabergé.

Representing another publicly traded company intending to mine ruby in Mozambique, Christiaan Jordaan of Mustang Resources LLC told us about Mustang’s initial 2016 bulk sampling and exploration activities. The company hopes to become an important supplier of commercial and gem-quality ruby.

Marcello Ribeiro of Belmont Group updated us on developments at the company’s Belmont and Canaan emerald mines at Itabira, Brazil. He emphasized the importance of sound mine planning through fieldwork and trace-element analysis of potential emerald host rocks.

David Bindra of B&B Fine Gems confirmed the importance of the secondary market for exceptional gems, which are in very high demand. He noted less consumption of commercial to mid-grade material.

A partnership between Morocco’s Geostone Group and U.S. gem carver Glenn Lehrer illustrates another interesting development. Production from Geostone’s Moroccan amethyst mine is cut to Lehrer’s high standards in an Indian factory, featuring a branded designer cut with high weight retention. The resulting faceted stones—and finished amethyst jewelry—are sold directly to consumers through television merchandising. The approach helps build a niche for Moroccan amethyst and brings the benefits of scale to designer cutting, which is usually associated with unique pieces.

Eternity Emerald’s Arthur Groom shared his rough emerald buying expertise with us, especially his years of experience negotiating with miners in Afghanistan’s Panjshir Valley. He noted that the quality of Afghan emerald is not realized in the West because large, fine crystals are often damaged by improper blasting and extraction techniques.

Potentate Mining’s Warren Boyd showed us sapphire production from Montana’s Rock Creek alluvial deposits, including a remarkable 12.61 ct blue sapphire cut from a 6.37 g rough crystal. Although most of the production has greenish or brownish pastel colors, it reacts well to heat treatment. Boyd told us bright natural colors are in high demand. He showed several suites of fancy sapphires cut by his client, Americut. Montana’s alluvial sapphire deposits will be the subject of an upcoming G&G field report.

The trend toward ethical, sustainable business practices and transparent supply chains is exemplified by Sheahan Stephen of Sheahan Stephen Sapphires, Inc. His company documents and guarantees the integrity of the gems it sells from the mine, through treatment and cutting and directly to the customer.

Nigeria is an under-documented source of fine rubellite and indicolite tourmaline and predominantly blue basalt-hosted sapphire. For this reason, we especially welcomed talking to Zoe Michelou, who represented a Nigerian mining company. She updated us on production of these gemstones from that country’s Oyo, Kwara, and Taraba states.

Gem paintings, which GIA has documented in Vietnam and Mogok, made their first appearance at Tucson. Wanlaya Suwannapirom’s Than Thong Arts booth featured an array of art-inspired handmade portraits and miniatures. The technique converts otherwise unusable natural gem fragments into valuable art objects and wearable art such as pendants and pins.

Gem artist Alexander Kreis showed us a spectacular 27.20 ct freeform tanzanite complemented by a custom ring mount made by his mother Sonja, a master goldsmith. They related the importance of the story behind a jewelry piece for their clients—how details of the stone’s cut and the ring’s design represent the toil and effort of the Tanzanian miners and imbue the piece with added significance.

Fran Mastoloni provided a cultured pearl market update, explaining how careful selection and matching of the different cultured pearl types into a range of varied necklaces help him cater to the market’s desire for distinctive “fashion-forward” yet flexible jewelry.

Dealer Bill Vance of Vance Gems exhibited rare gem-quality magnesio-axinites from just one location in Merelani, Tanzania. This material displayed remarkable fluorescence, and we hope to report further on its chemistry in the near future.

We were delighted to find a Southwest-inspired Starship Enterprise, handmade by David Freedland of David R. Freedland Jr. Designs in sterling silver. This quirky blend of science fiction and traditional inlay work is one of the show’s unexpected finds.

Finally, no survey of the Tucson shows would be complete without Paula Crevoshay’s one-of-a-kind designs. This year, she showcased a bracelet featuring five large freeform fire opals, a swallowtail butterfly pin with yellow and black diamonds, an elephant pin with mother-of-pearl tusks, and a stunning cuff bracelet featuring a spectacular boulder opal centerpiece. @topic:11


Publish Year: 2018 Title: Tucson 2018 Overview Abstract: Figure 1. Although traffic at the AGTA show was lighter than in some previous years, demand was brisk and most traders were satisfied with their 2018 business. Photo by Kevin Schumacher.

Every February the gem and mineral world descends on Tucson, transforming the downtown convention center and a great many of the city’s hotels into a fascinating collage of traders bearing goods from all over the planet (figures 1 and 2).

Figure 2. Customers in Tucson sought out unique goods, a trend that carried over from last year's shows. Photos by Kevin Schumacher.
Many of the exhibitors we spoke with described 2018 as the strongest year since 2008. Although traffic wasn’t especially heavy at the AGTA and GJX shows, most dealers there enjoyed brisk sales and healthy demand for high-quality goods. Some of the same trends from last year were evident. Customers still sought out one-of-a-kind pearls and colored gemstone pieces, and the secondary market in the U.S. for exceptional pieces remained highly significant. There was a continuing focus on untreated material and ethically sourced gemstones, a subject articulated for us by Jean Claude Michelou of the International Colored Gemstone Association and officials from the Responsible Jewellery Council. Market realities such as very strong price competition for newly mined gem rough were mentioned as a major challenge by many dealers and cutters.

In addition to strong demand for high-end gems, many dealers at AGTA and GJX reported a surge in more moderately priced goods. Meanwhile, dealers at other locations told us the commercial end of the market remained soft.

Pantone’s color of the year for 2018, a shade of purple called Ultra Violet, was well represented at the shows. A couple of dealers had exceptional examples of purple sillimanite. Many dealers posted strong sales of pastel-colored spinel—in pink and lavender hues—in suites and sets as customers found the scarcity and high prices of red spinel prohibitive. In a similar vein, Margit Thorndal of Madagascar Imports reported strong demand for purple-lavender spinel and purple sapphire from Madagascar, as well as teal hues of unheated Montana sapphire.

We noted that electric blues, teals, hot pinks, hot yellow greens, and pastel-colored gems were quite popular. Bill Larson of Pala International pointed to this trend and showed us a number of spectacular examples from his inventory. Fine blue zircon from Cambodia was prominent, as was attractive sphene from Zimbabwe and Madagascar.

Figure 3. Dave Bindra of B&B Gems showed us a selection of standout gems from the secondary market, including this 61.92 ct Imperial topaz. Photo by Kevin Schumacher.
Dave Bindra of B&B Fine Gems said his company was very active in scouring the secondary markets for old jewelry items and gemstones that have been out of circulation for decades. This year’s standouts were two incredible red beryls from Utah (a 3 ct emerald cut and a 4 ct round brilliant), a 61.92 ct Imperial topaz (figure 3), and a fine selection of Kashmir sapphires, which were very sought after this year. Fran Mastoloni of Mastoloni Pearls updated us on current trends in the cultured pearl market and showed examples of unique pieces.

Dealers specializing in domestic gems reported strong demand. John Woodmark of Desert Sun Mining & Gems told us the market for Oregon sunstone was the strongest he had seen since the andesine controversy challenged suppliers of the natural Oregon gem a decade ago. As a result, the company has scaled up its mining activities and built new relationships with gem cutters to improve supply to its clients.

As always, the Tucson shows were a rich source for the latest on global colored stone supply. Conversations with Luis Gabriel Angarita and Edwin Molina revealed insights on the mining and branding of Colombian emerald. Marcelo Ribeiro shared details on mining and cutting at the Belmont emerald mine in Brazil. Alexey Burlakov offered his perspective on Russian demantoid production, while Stephan Reif did the same for demantoid from the Green Dragon mine in Namibia. Miriam Kamau shared information on her Kenyan tsavorite mining operation and offered her own inspirational success story. From Jürgen Schütz of Emil Weis Opals we learned about the cutting of opal, both play-of-color and nonphenomenal, from sources around the world. Alexander Arnoldi explained Arnoldi International’s strategy in sourcing and cutting high-quality aquamarine and tourmaline. We also saw examples of gem production from unexpected sources: Indonesian opal and turquoise from the state of Arkansas.

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Tucson is also a destination for many leading gem artists and jewelry designers. Award-winning carver Michael Dyber explained the inspiration behind some fantastic one-of-a-kind pieces bearing his signature optical disks. At the intersection of science and art, Rex Guo discussed his approach to recutting gems to optimize light performance and beauty. And designers Paula Crevoshay and Erica Courtney showed us striking and innovative new pieces with unexpected and fascinating gem combinations. @topic:11


Publish Year: 2018 Title: Zoning In on Liddicoatite Exhibit Abstract: Figure 1. At the 64th annual Tucson Gem and Mineral Show, the GIA Museum hosted Zoning In on Liddicoatite in honor of Richard T. Liddicoat’s 100th birthday. Photo by McKenzie Santimer.
The calcium-rich lithium tourmaline liddicoatite was first recognized as a new mineral species in 1977. It was named by research staff at the Smithsonian Institution after GIA’s then-president, Richard T. Liddicoat (1918–2002). In honor of Mr. Liddicoat’s centennial birthday, the GIA Museum hosted an exhibit titled Zoning In on Liddicoatite at the Tucson Gem and Mineral Show, February 8–11. With highlights from Mr. Liddicoat’s career alongside crystals and polished crystal slices showing spectacular color zonation (figure 1), the exhibit was a fitting tribute to GIA’s own “Father of Modern Gemology.” @topic:2


Publish Year: 2018 Title: Cabochons Fashioned from the Shell of Crassostrea Virginica Abstract: Figure 1. The ten cabochon-cut gems examined are shown alongside the valves of C. virginica (Eastern or American oyster). The interior and exterior valves shown belong to one oyster. Photo by Diego Sanchez; samples courtesy of Anne Dale.

Crassostrea virginica, the so-called Eastern or American oyster, is a commercial seafood widely distributed along the east coast of the United States to the Gulf of Mexico (“Indian River Lagoon Species Inventory,” Smithsonian Marine Station at Fort Pierce, 2008, https://www.sms.si.edu/irlspec/Crassostrea_virginica.htm). Connecticut, Virginia, and Mississippi have all designated the Eastern oyster as their official state shell, and cabochons cut from this bivalve are the official state gemstone of Louisiana (http://legis.la.gov/Legis/Law.aspx?d=103557). These specimens are marketed under the trade name LaPearlite.

Figure 2. Left: A 3.09 ct cabochon showed various surface structures consisting of a non-directional patchwork of cells near the center to a broad mottled appearance in the outer area, together with natural brownish layers of shell formation. Right: Higher magnification of another cabochon’s surface revealed a distinct patchwork structure. Both samples displayed a whitish sheen on the surface when illuminated with a fiber-optic light. Photomicrographs by Artitaya Homkrajae; fields of view 11.90 mm (left) and 5.24 mm (right).
The Carlsbad laboratory received ten LaPearlite cabochons together with a shell for examination (figure 1). The cabochons exhibited low domes and flat bases and ranged from 1.65 to 6.12 ct. They measured from 6.85 × 6.60 × 3.80 mm to 14.40 × 10.30 × 5.30 mm and possessed non-nacreous surfaces, with the majority displaying a natural brownish yellow banded structure typical of shell formation. Microscopic examination revealed that the main white surface and subsurface structure varied from a patchwork of nondirectional cells or segments to a broad mottled appearance within individual specimens, as well as from specimen to specimen. These structures exhibited a reflective whitish sheen when illuminated by a fiber-optic light or other bright oblique lighting, creating a shimmery phenomenon (figure 2). A similar patchwork pattern has been noted on scallop pearls and shells of the Pectinidae family (K. Scarratt and H.A. Hänni, “Pearl from the lion’s paw scallop,” Journal of Gemmology, Vol. 29, No. 4, 2004, pp. 193–203). Under long-wave UV radiation (365 nm), the white portions of all the cabochons and the shell were inert, while the yellow portions showed a weak to moderate yellow fluorescence, and the shell’s dark purple adductor muscle scar exhibited a weak red fluorescence.

Figure 3. Raman spectra collected using 514 nm laser excitation on the white and purple areas of the interior of the C. virginica valve. The white area shows calcite peaks at 280, 712, 1085, and 1437 cm–1, and the purple area shows aragonite peaks at 703 and 1085 cm–1, along with several broad pigment-related bands.

Figure 4. A PL spectrum collected using 514 nm laser excitation on a purple area on the interior of a C. virginica valve displays clear triple bands at approximately 620, 650, and 680 nm related to the porphyrin pigment.
Raman spectroscopic analysis with a 514 nm argon-ion laser subsequently verified that the white and yellow portions of the cabochons and shell were calcite with peaks at 280, 712, 1085, and 1437 cm–1. No peaks indicating the possible presence of pigments were detected in the yellow areas. Moreover, Raman spectra collected on the shell’s dark purple adductor muscle scar produced aragonite peaks at 703 and 1085 cm–1 along with several relatively weak broad pigment-related bands (figure 3). PL spectra collected with 514 nm laser excitation on the same areas showed clear triple bands at approximately 620, 650, and 680 nm (figure 4). The PL spectra and fluorescence reaction indicate the purple color is associated with the pigment porphyrin (Y. Iwahashi and S. Akamatsu, “Porphyrin pigment in black-lip pearls and its application to pearl identification,” Fisheries Science, Vol. 60, No. 1, 1994, pp. 69–71; L.H. Arma et al., “Red fluorescence lamellas in calcite prismatic layer of Pinctada vulgaris shell (Mollus, bivalvia),” Optical Materials Express, Vol. 4, No. 9, 2014, pp. 1813–1823). None of the studied cabochons showed purple areas to examine for comparison. Interestingly, the Raman spectra obtained from the white and purple areas of the same mollusk that were previously referenced in the literature (K. Scarratt et al., “A note on a pearl attached to the interior of Crassostrea virginica (Gmelin, 1791) (an edible oyster, common names, American or Eastern oyster),” Vol. 30, No. 1/2, 2006, pp. 43–50) differed slightly from the findings in Journal of Gemmology this work. The samples in this submission were also analyzed by energy-dispersive X-ray fluorescence (EDXRF) chemical analysis and showed low levels of manganese (Mn), confirming their saltwater environment.
As with all shell mollusks, C. virginica is capable of producing pearls. However, the cabochons in this study provided useful gemological and spectroscopic information for future reference that can no doubt assist with identifying the composition of pearls produced by the mollusk (C.P. Idyll, “The pearls of Margarita,” Americas, Vol. 19, No. 8, 1967, pp. 8–14). Although the samples could be mistaken for agate at first glance, owing to their distinctive banding, it would soon be apparent that they were pieces of fashioned shell. The samples demonstrate how creative work can turn nature’s beauty into an attractive gemological material. @topic:5


Publish Year: 2019 Title: The Granada Gallery Abstract: Figure 1. Paraíba-type tourmalines from Mozambique. Left to right: a 29.34 ct oval, a 3.01 ct pear set in a rose gold ring, a 51.62 ct oval, and a 65.17 ct trillion cut. They were displayed with a 224.6 g gold nugget from Victoria, Australia. Photo by Robert Weldon/GIA, courtesy of the Granada Gallery.

Housed in a 1908 vintage Arts and Crafts building on Granada Avenue in Tucson, the Granada Gallery is replete with what its owners call “items of geologic relevance,” or rare mineral and fossil specimens. These are carefully lit and displayed to accentuate their beauty and often combined with faceted and carved gem materials, one-of-a-kind objets d’art, and finished jewelry. For the visitor, this earth-to-jewel experience accentuates the jewelry industry’s rich history.
“We want to further an exchange of ideas between artists, scientists, curators, and collectors,” explained Rüdiger Pohl, who owns and curates the traveling gallery along with Alison Magovern. The gallery’s Tucson space has been open during the gem and mineral shows since 2013.

Figure 2. Pezzottaite is carved into a coiled dragon by Patrick Dreher. The pezzottaite crystal measures 9.6 × 4.7 × 2.1 cm, while the carved pezzottaite is 201.03 ct. Photo by Robert Weldon/GIA, courtesy of the Granada Gallery.

Figure 3. Left: Jochen Leën’s aquamarine and gold bracelet is displayed with a 6.1 × 9.1 × 8.5 cm (369.2 g) aquamarine crystal from Pakistan. Right: This 3436 g aquamarine from the Pohl collection measures 5.0 × 9.4 × 7.5 cm, and is also from Pakistan. Aside from its quartz overgrowth, the crystal exhibits phantom growth features and iridescence. Photos by Robert Weldon/GIA, courtesy of the Granada Gallery.
The Granada Gallery collaborates with global artists and collectors, “sparked by happy coincidences, shared visions, and the passion for creating something unique,” the owners said. This year’s exhibit included a collection of Paraíba-type tourmalines from Mozambique (figure 1) and a stunning dragon—carved from the rare mineral pezzottaite, found in a single deposit in Madagascar—by Patrick Dreher (figure 2). Pakistani aquamarine was on display in rough and mounted forms (figure 3). And a year-long collaboration with the Kreis family of Idar-Oberstein, Germany, resulted in their “Chanting of the Stars” piece (figure 4).

Figure 4. “Chanting of the Stars” was created by the Kreis family of Idar-Oberstein. The “chanting” refers to the sound of a comet entering the earth’s atmosphere. The rutilated quartz comet’s impact with earth is denoted by the smoky quartz carving. Photo by Robert Weldon/GIA, courtesy of the Granada Gallery. @topic:6


Publish Year: 2019 Title: Ponderosa Sunstone Update Abstract: Two Oregon sunstones weighing 7.07 and 2.48 ct. The stone on the right, faceted by Larry Woods, has a very rare deep red color. Photo by Robert Weldon/GIA, courtesy of John Woodmark, Desert Sun Mining.

John Woodmark, president of Desert Sun Mining and Gems (Depoe Bay, Oregon), updated us on the Ponderosa mine, which he calls the most productive source of Oregon sunstone (see above). Demand has increased annually over their 17 years of production, he said. With the larger excavator and high-capacity screen they brought on in 2015, they now mine about 4,300 kg (4.8 tons) of sunstone rough per year, up from about 2,000 kg (2.2 tons) in 2014. About 3% of this material is facet grade. Ponderosa now produces 4,000 to 5,000 cubic yards of concentrate in seven days—more than enough to process in one season (which only lasts five or six months due to snow at the high elevation). Desert Sun was once limited to mining at about 50 feet deep, but the excavator has allowed them to go a few hundred feet deep into the source. Woodmark said the sunstones at that depth are larger and less fractured, and there are some excellent red stones of good size.
Woodmark said demand is especially strong from American and European customers age 45 and under because they want natural, untreated gemstones such as sunstone, opal, and jade. They also love Oregon sunstone’s schiller effect, a sparkle caused by reflective copper platelets that makes the stone “different from what their friends have.” Desert Sun will be using social media this year for the first time to reach customers looking for unique gemstones.
Jewelers are excited about Oregon sunstone because of the potential high markup, according to Woodmark. He noted that sunstone isn’t competing with diamond, ruby, sapphire, and emerald, for which a jeweler might see a 10% or 15% profit margin. Oregon sunstone can yield a triple or quadruple markup, yet it is still relatively affordable: Woodmark said the yellow sunstones sell for about $30 per carat while the reds can go for $300 to $4,000 per carat. Sunstone’s affordability, profit margin, and appeal to young consumers make it attractive to jewelers.

	John Woodmark updates us on the Ponderosa mine and the sunstone market.

Woodmark said the jewelry industry’s demand for calibrated sunstones continues to grow, and Desert Sun now receives significant orders from large companies. A typical order might be a thousand 5 mm rounds of orange sunstone. Every color sells well, he told us, but it is difficult to get a specific band of color in natural, untreated gemstones, so they are trying to grade more consistently. Desert Sun has seven colors, each graded with and without schiller, so overall there are 14. He tries to educate jewelers, manufacturers, and designers on the fact that color in natural stones is more variable—and that many have unique color—to encourage them to use more than one color in their pieces.
Woodmark sees a bright future for Oregon sunstone as more consumers become aware of it. He acknowledged that there will come a time when he and Bruce Moore, Desert Sun’s executive vice president, will have to step away from the deposit. “We’re barely scratching the surface of what people could do with this mine,” he said. Desert Sun only exhibits at the AGTA show in Tucson, but Woodmark said if someone were to take over the mine, they could do 10 shows a year across the United States. At that point, he said, sunstone would “take off.”

	Sonja Kreis describes an Oregon sunstone and gold nugget piece by Kreis Jewellery. @topic:2


Publish Year: 2019 Title: Emerald in Rock Crystal Quartz Abstract: A prismatic emerald crystal within a rock crystal quartz. Photomicrograph by Nattida Ng-Pooresatien; field of view 12.5 mm.

Rock crystal is a transparent and colorless macrocrystalline variety of quartz (SiO2) that often has cavities containing liquid and gas two-phase inclusions. Many different minerals also form as inclusions within rock crystal quartz. Typical varieties of included quartz for gem use are rutilated quartz, tourmalinated quartz, and strawberry quartz. Specimens may also contain several other types of mineral inclusions.
Recently, the author examined a 10.95 ct rock crystal quartz cabochon that contained elongate rod-shaped green crystals (see above). The green crystals showed hexagonal cross-section and were identified by Raman spectroscopy as beryl. Ultraviolet/visible/near-infrared (UV-Vis-NIR) spectroscopy showed a chromium (Cr) spectrum, which confirmed that the green crystals were emerald. This amazing inclusion has been previously reported in a rock crystal quartz specimen (Fall 2008 Lab Notes, p. 258), but this is the first time the author has examined a gem-quality rock crystal quartz cabochon with a perfectly hexagonal emerald crystal inclusion. @topic:1


Publish Year: 2019 Title: Dravite from Mozambique with an Abundance of Pyrite Inclusions Abstract: Figure 1. Six yellow to brownish yellow faceted dravite tourmalines (0.47–2.8 ct) from Mozambique, many of which contained distinct metallic inclusions of pyrite. Photo by Weizhi Huang.

In the summer of 2017, author JP encountered a parcel of transparent yellow to brownish yellow tourmalines at the gemstone market in Chanthaburi, Thailand. The six faceted tourmalines shown in figure 1 revealed properties consistent with tourmaline. LA-ICP-MS analysis was performed to determine their major chemical components, which were: 11.56–12.31% MgO, 9.98–10.34% B2O3, 2.62–2.82% Na2O, 0.68–1.06% CaO, 0.17–0.45% TiO2, and 0.11–0.25% FeO (total iron). Minor amounts of Li, K, V, Cr, Mn, Zn, Ga, and Sr were also detected, indicating dravite tourmaline.

Figure 2. The dravites contained distinctive inclusions of pyrite, which were confirmed by Raman spectrometry. Photomicrograph by Weizhi Huang; field of view 0.8 mm.
These dravites were noteworthy for their numerous euhedral pyrite crystal inclusions (figure 2), confirmed by Raman. This was previously reported without Raman analysis (see Spring 2007 GNI, pp. 73–75). This is the first time the authors have seen so many intact pyrite crystals in yellow to brownish yellow gem-quality dravite from Mozambique. @topic:1


Publish Year: 2019 Title: Dive Into Summer: Mozambique Ruby, Madagascar Sapphire, and Black Nephrite from China, Plus an Opal Inclusions Chart Abstract: With 2019 already past the halfway mark, we are very pleased to present our Summer edition. Inside you’ll find new insights into a variety of gem materials.
The issue leads with a review of the past decade of ruby from Mozambique. Since 2009, Mozambique has become the world’s leading supplier of ruby, transforming the market in the process. GIA has been visiting these deposits since the initial discoveries, and now Wim Vertriest and Sudarat Saeseaw from the Bangkok laboratory add a new chapter to this story with an overview of production and distribution, as well as a comprehensive gemological characterization and a discussion of the most common treatment processes applied to material from this important locality.

“Since 2009, Mozambique has become the world’s leading supplier of ruby, transforming the market in the process.”

Next, Billie Hughes from Lotus Gemology and Rosey Perkins with Fura Gems present the results of low-temperature heat treatment experiments on sapphire from Madagascar. Increasing numbers of these stones are being heated to relatively low temperatures (below 1350°C) to lighten their color. The authors show the changes in these goods, providing a means of separating unheated and heated Madagascar sapphire.
Moving from Africa to Asia, the issue continues with a study of black nephrite from a deposit in southern China. Qian Zhong, a PhD student of mineralogy at Tongji University in Shanghai, leads a team of professors from that university in characterizing 12 nephrite samples from the Guangxi region.
In the fourth article, Jean-Pierre Gauthier from the Gemological Research Center of Nantes and his coauthors characterize “flame structure” in 37 pearls from bivalves of the Tridacnidae family. Careful observation revealed evidence of rotation during growth, a feature also seen in numerous pearls from Pinctada margaritifera.
The next article, also on pearls, presents an unusual identification challenge that confronted researchers at the Max Planck Institute for Chemistry, Johannes Gutenberg University, and GIA’s New York and Bangkok laboratories. Two pearls were examined by the team of authors, who were unable to positively identify their origin (natural or cultured), their growth environment (freshwater versus saltwater), or the mollusk that produced the pearls.
In our last article, Nathan Renfro and coauthors present an opal inclusions chart, the fifth in their series on micro-features in gemstones. Laminated versions of all of these large, colorful wall charts are also available at store.gia.edu.
Highlights from the Lab Notes column include a rough diamond with a coating of fake green “radiation stains,” a study on the separation of kornerupine and prismatine, and the first report of a color-change spessartine garnet examined by GIA. Gem News International features brief but thorough studies on the gemological characteristics of jadeite from the Polar Urals of Russia, more than 800 natural freshwater pearls from the Mississippi River system, and rubies from the Rock Creek deposit in Montana. As always, Micro-World reveals a fascinating gallery of inclusion scenes, while the Diamonds from the Deep section (now a year old) outlines the basic geological and practical features of kimberlites, the earth’s diamond delivery system.
We hope you enjoy the Summer 2019 edition of Gems & Gemology! @topic:9


Publish Year: - Title: Citrine from Zambia Abstract: Figure 1. These citrines (3.38–43.86 ct) showing the range of color from the new Zambian deposit are reportedly untreated. Photo by Robert Weldon.

                      In September 2011, GIA was informed by gem and mineral dealer Dudley Blauwet about a new find of citrine, which was represented to him as natural-color material from the Kitwe area of Zambia. He obtained ~1 kg of the rough at the 2011 Tucson gem shows from a regular supplier of African rough. Faceting of 208.5 grams of rough yielded 29 stones totaling 268.08 carats. Four of the stones were concave cut, and the largest one weighed 48.69 ct.

	Figure 2. Hazy clouds and bands are common features in the Zambian citrine. Photomicrograph by D. Beaton; image width 2.7 mm.
Mr. Blauwet loaned seven of the cut citrines to GIA for examination, ranging from 3.38 to 43.86 ct (figure 1). Concave facets on the three largest pieces accentuated their brilliance. The color of the citrine ranged from pale slightly brownish yellow to brownish orangy yellow, and the seven stones showed the following gemological properties: RI— no = 1.542, ne = 1.552; birefringence—0.010; hydrostatic SG—2.65–2.66; UV fluorescence—inert to both long- and short-wave UV radiation, except for one pale yellow sample that fluoresced very weak white to long-wave UV; and no features seen with the desk-model spectroscope. Microscopic examination revealed straight and angular color zones, as well as a general haziness and bands of hazy particles (figure 2), which proved natural origin and were similar to those described in citrine from Sri Lanka (E. J. Gübelin and J. I. Koivula, Photoatlas of Inclusions in Gemstones, Vol. 2, Opinio Publishers, Basel, Switzerland, 2005, p. 573). The 3.38 ct stone also contained a plane of parallel tubules and two-phase inclusions (figure 3). Viewed with cross-polarized light, minor areas of Brazil-law twinning were seen in only the two smallest samples.

	Figure 3. The 3.38 ct triangular modified brilliant in figure 7 contains a plane of elongated
	tubules and two-phase inclusions. Photomicrograph by D. Beaton; image width 1.5 mm.
FTIR spectroscopy revealed the absence of a 3595 cm–1 band. This feature is sometimes used as confirmation of natural quartz, especially amethyst, when it is well resolved and there are no diagnostic natural inclusions (S. Karampelas et al., “Infrared spectroscopy of natural vs. synthetic amethyst: An update,” Fall 2011 G&G, pp. 196–201). In citrine this feature is often absent, so proper identification must rely on inclusion observation, or the analysis of trace elements (C. M. Breeding, “Using LA-ICP-MS analysis for the separation of natural and synthetic amethyst and citrine,” www.gia.edu/gia-news-research-nr73109a).

Natural-color citrine is less common than other quartz varieties such as amethyst and smoky quartz. Assuming that the coloration of this citrine is natural—as represented by the supplier—this large, clean material makes a nice addition to the gem market. @topic:8


Publish Year: 1994 Title: The Anahí Ametrine Mine, Bolivia Abstract: The Anahí mine, Bolivia, has produced large amounts of amethyst, citrine, and amethyst-citrine for the gem market. Field and experimental investigations conclusively show that the amethyst-citrine color combination in quartz crystals from Anahí is natural and does not result from laboratory treatment. The unusual color patterns probably result from the uncommon geologic conditions under which these quartz crystals formed, although the crystal chemical properties controlling the sector color zoning still elude explanation. From 1989 to the present, more than 100 tons of ametrine crystals, yielding 40-80 kg of cutting rough per ton, have been produced. @topic:1


Publish Year: - Title: Emeralds: Colombia’s Buried Treasure Abstract: A miner holds an emerald in the mine office in the village of Coscuez, Colombia. Photo by Eric Welch/GIA

No one can be more familiar with or cherish the magnificent emerald more than the miner himself. At the end of a long day of labor, the miner illuminates and holds firmly the prize of the day.

Miners in Colombia have unearthed the world’s most sought after and valuable of the green gemstones. The characteristic rich greens unique to Colombian emerald are historically appreciated more than any other locality on Earth.

To chart a “treasure map” of Colombia’s finest gemstones, start in the capital of Bogota. From there, draw a line due north for approximately 200 km (124 miles), into the Cordillera mountains of the Andes. Then, strike an arc 90° due east.

Buried within this quadrant, you will find some of the finest emeralds in the world, as verdant as the rainforest, mountains and valleys where they have been buried for millennia − and sought after for centuries. The renowned colored gemstone localities of Muzo, Coscuez and La Pita lie to the north, and Chivor to the east.

Lake Guatavita, 120 km (75 miles) west of Chivor, is steeped in legend and lore, garnished with flecks of truth. The raft of El Dorado (The Golden Man) from the Muisca period depicts a ceremony on the sacred lake. It is said that the legendary El Dorado would be covered in gold dust daily and bathed in the waters of Lake Guatavita.

Spanish and English Conquistadors in the 16th and 17th centuries avidly sought the ceremonial gold dust and precious jewels thrown into the lake.

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The pre-Columbian emerald and gold jewelry seen in the gallery above could very well be examples of the types of emerald jewelry used in these rituals and spurred European Conquistadors in their search for the gold and jewels of El Dorado.

La Pita, another well-known emerald mining locality, is home to Itoco, a mythical mountain peak named for the son of queen Fura and her husband Tena. Legend says that tears shed in the tragic love story of Fura and Tena turned into beautiful green stones that lay buried underground.

Emeralds are not the only treasure buried in the verdant land of Colombia. Rubies, sapphires and diamonds are also found there, though more rarely. Feast your eyes on the rainbow of colors of gemstone treasures from deep within the land of Colombia—red rubies, blue sapphires and yellow diamond. @topic:9