Publication Year: 2014 Title: Mexican Opal – Tucson 2014 Abstract: Figure 1. This rhyolite matrix specimen contains opal-filled cavities displaying play-of-color. Photo by Eric Welch; courtesy of Opalos & Artesanias Mexicanas.

Jorge Tamayo Carrillo (Opalos & Artesanias Mexicanas, Magdalena, Mexico) outlined current production of fire opal at his family’s mine, located 10 km south of Magdalena in Jalisco, Mexico.

	Jorge Tamayo CarrilloOpalos & Artesanias Mexicanas

In the first two videos, Jorge Tamayo explains the operation of his family’s opal mine and the work beyond mining to cut, polish, and prepare the array of gems at his Tucson GJX show booth. In the third video, Andres Carrillo demonstrates the beauty and variety of appearances Mexican opal provides.
Tamayo said the mine was shut down several years ago. His family took a risk and reopened it, and now they have worked it for more than five years. The material they exhibited at the GJX show represented several years of production.

The operation employs about 20 people. The miners look for opal-filled cavities (figure 1) in the rhyolite host rock. Veins last anywhere from two days to a few years on occasion. Explosives are used to break the host rock, and dump trucks move the ore to the surface, where workers break it up further with small hammers to extract the opal.

Production is put aside for six months to a year to minimize the risk to customers that the opals might show crazing due to water loss. At this point, Tamayo estimates, only 5% of the material might craze. Opalos & Artesanias Mexicanas has now been in business for 27 years, and the second-generation company prides itself on full disclosure. Its clientele consists of buyers in the United States, Japan, China, and Germany. All cutting is done in house or by local artisans, as the company aims to support the local community.

View Gallery

Patience pays off for Opalos & Artesanias Mexicanas
Red, pink, orange, yellow, and colorless (“clear” or “white”) specimens without play-of-color are polished by hand into freeform shapes or used for faceted stones (figure 2). Fine material with play-of-color is fashioned into cabochons or freeform shapes (figure 3). Lower-end material—essentially rhyolite matrix with gemmy opal portions—is fabricated by hand into cabochons for use in rings, bracelets, and cufflinks. @chapter:39


Publication Year: - Title: Topaz Quality Factors Abstract: Blue topaz makes a perfect gem material for artistic carvings. - Lydia Dyer, courtesy of John Dyer & Co.

Color
Red is one of the most sought-after topaz colors and represents less than one-half of 1 percent of facet-grade material found. The color the trade calls imperial topaz is highly prized and very rare. Many dealers insist that a stone must show a reddish pleochroic color to be called imperial topaz. The reddish pleochroic color often appears at the ends of fashioned gems—like pears and ovals—that have an otherwise yellow-to-orange bodycolor.

	Imperial is one of the most highly prized topaz colors, as seen in this spectacular prize-winning, orangy-red, flame-shaped gem. - Gem courtesy of John Dyer & Co.
A fashioned topaz that displays a combination of two colors is called bicolor topaz. Some say that pink topaz, often called rose topaz, resembles a pink diamond or a bright pink sapphire. Pink topaz has certain advantages over these two gems. It’s much less expensive than pink diamond, and it’s often available in larger sizes than either diamond or sapphire.

Dealers often use the trade term “sherry topaz” for yellowish brown or brownish yellow to orange topaz. The term comes from the color of sherry wine. Stones in that color range are also sometimes called precious topaz. This helps distinguish them from less expensive citrine and smoky quartz, both of which look similar to, and are frequently misrepresented as, topaz.

Golden or yellow topaz lacks the prized red overtones of imperial topaz. It’s also much more abundant and therefore less valuable. Although brown topaz is also less valuable, it has been used in striking pieces of jewelry and ornamental art.

In nature, topaz is most commonly colorless, and naturally strong blue gems are extremely rare. In the marketplace, however, strong blue shades are plentiful. Treatments are the reason for this. Treaters use a combination of radiation and heat to produce blue hues in topaz. Since the 1970s, treatments have brought blue topaz to a broad market.

	Irradiation and heat treatment transform colorless topaz to various shades of blue. Starting in the 1970s, treatment created a huge market for inexpensive blue topaz. - © GIA & Tino Hammid
When it was first introduced to the market, treated blue topaz sold for $20 to $40 per carat. But oversupply led to huge drops in wholesale prices, down to a few dollars or less per carat. Today, blue topaz is basically a mass-market gem, and price is often the most important consideration for many buyers. Uniformity of color and cut is also important, especially for mass-market jewelry manufacturers.

	The nature of the starting material and the type of treatment determine the blue that results. These treated topaz stones, weighing from 2.72 carats to 7.86 carats, show a range of hue, tone, and saturation. - Courtesy Chuck Ashbaugh
Clarity
Fashioned topaz gems are often free of visible inclusions or flaws. This especially true of blue, colorless, and yellow topaz.

	This ring, designed by Maria Canale, holds a 12.25-carat untreated topaz from Brazil. The gem has no visible inclusions. - Courtesy Richard Krementz Gemstones
Cut
Because topaz crystals are usually elongated or columnar, they’re often cut as long oval or pear shapes to improve yield. If the rough is strongly colored, the cutter often chooses the emerald cut because that cutting style maximizes color and retains the most weight.

Topaz is cut in a wide variety of shapes and cutting styles. Production includes all the standard gem shapes such as ovals, pears, rounds, cushions, triangles, marquise, and emerald cuts as well as designer-inspired fantasy shapes.

	A modern mixed cutting style dramatically intensifies the color of this 14.68-carat bright blue topaz. - Lydia Dyer, Topaz StarBrite courtesy of John Dyer & Co.
Cutting styles are also well represented. Brilliant cuts with triangular and kite-shaped facets, step cuts with concentric rows of parallel facets, and mixed cuts usually consisting of brilliant-cut crowns and step-cut pavilions are all common. Designer cuts fashioned by hand and machine are popular, too.

	The uniform color of treated blue topaz makes it a highly suitable material for cutting into standard sizes for jewelry.
Because there is an abundant supply of treated blue topaz, it’s often cut into calibrated sizes for use in mass market and multi-stone jewelry.

Carat Weight
Standard topaz cuts for the jewelry industry include a wide range of shapes and sizes. The gem is inexpensive in smaller sizes, but prices rise for gems above 10×8 mm.

	This 61.78-carat carved topaz is a truly unique sculptural piece. Skilled workmanship intensifies the blue color to produce an effect like shimmering droplets of water. Blue topaz makes a perfect material for large carvings due to availability in large sizes. - Lydia Dyer, Blue Topaz Sculptural Gem courtesy of John Dyer & Co. @chapter:1


Publication Year: 2016 Title: Metal Sulfide in Pyrope Abstract: Figure 1. The prominent sulfide inclusion in this 2.02 ct pyrope is clearly visible under the table facet. Photo by Kevin Schumacher.

	The 2.02 ct “inclusion gem” shown in figure 1 is not only spectacular to inclusion enthusiasts, but also a scientific mystery. This vanadium- and chromium-bearing pyrope was cut from one of the samples featured in G&G’s Winter 2015 issue (Z. Sun et al., “Vanadium- and chromium-bearing pink pyrope garnet: Characterization and quantitative colorimetric analysis,” pp. 348–369). The stone was faceted by Jason Doubrava (Poway, California) to display a relatively large, euhedral sulfide crystal inclusion. Sulfide crystals were observed in several of the samples in the 2015 study; the exact nature of the inclusions could not be determined by Raman analysis, but all displayed a metallic luster in surface-reflected light. Magnification also revealed a cloud of minute acicular inclusions resembling rutile surrounding the crystal (figure 2). Along with the elements expected for pyrope, such as Si, Al, Mg, Mn, and Fe, energy-dispersive X-ray fluorescence (EDXRF) analysis detected peaks for sulfur and rhodium. While sulfur would be expected in a metal sulfide, the rhodium peak is a mystery. Rhodium sulfide does exist, but explaining the presence of rhodium in this garnet would require destructive testing. In this case beauty trumps science, because this gem is truly a wonderful addition to the collection of this inclusionist and will thus remain a gemological curiosity.

Figure 2. A cloud of extremely fine acicular inclusions in the pyrope surrounds the sulfide when viewed under the microscope with diffuse reflected light. Photomicrograph by Nathan Renfro; field of view 5.41 mm. @chapter:10


Publication Year: 1995 Title: Spring 1995 G&G Lab Notes Abstract: Alexandrite with Pleochroic Twinned Growth Zones
Untreated or Fracture-Filled Diamond
Treated Old-Mine Cut Diamond
Triangular Inclusions in Diamond
Treated-Color Red Synthetic Diamond
Emerald with Unusual Flash-Effect Colors
Bleached and Impregnated Jadeite with Distinctive Surface Texture
Treated and Untreated Jadeite Beads in One Necklace
Dyed Green Nephrite
Blister Pearl Attached to Shell
Sapphire with Diffusion-Induced Color and Star
Synthetic Star Sapphire with an Unusual Color
Natural Spinel with a Dendritic Inclusion

To view the full section, download the PDF above. @chapter:32


Publication Year: 2013 Title: Book Review: From a Snowflake to an Iceberg: The McFerrin Collection Abstract: The 1902 Kelch Rocaille Egg. All 7 Kelch eggs created by Michael Perchin, Faberge's 2nd head workmaster; St. Petersburg. Height: 12 cm, Length: 14 cm. Given by Alexander Kelch to his wife Barbara Kelch-Bazonova. Image courtesy the Houston Museum of Natural Science.

              The McFerrin’s have one of the largest private collections of Fabergé objects and the exhibit contains over 350 items from their collection. This book was published on the occasion of the exhibition “Fabergé: A Brilliant Vision,” part of the McFerrin Collection at the Houston Museum of Natural Science.

In addition to descriptions and provenance of the items on display, this work contains essays on: the history of Peter Carl Fabergé and his businesses in St. Petersburg and Moscow, as well as of the Romanov family; the meaning and significance of imperial awards, gifts and objects; and Fabergé’s jewelry, animal and flower carvings, picture frames, fans, parasol and cane handles, eggs, bell pulls, cigarette cases, and more. There is also some information on designer Alma Pihl and his workmasters. Of course, this all accents the book’s wonderful photography.

The McFerrins’ belief in education and sharing their knowledge is mirrored by the book’s contributors, whose essays are each accompanied by a bibliography and provenance.

Reviewed by GIA Library Staff
Carlsbad, California @chapter:21


Publication Year: 1985 Title: A Preliminary Report on the New Lechleitner Synthetic Ruby and Synthetic Blue Sapphire Abstract: A new synthetic ruby and synthetic blue sapphire have been synthesized by Johann Lechleitner of Innsbruck, Austria. This article reports on the examination of one sample of each of these new synthetics and discusses means of identification. Although most of the gemological properties of these two synthetics overlap with those of their natural counterparts, they can be easily identified from natural corundum and from other synthetics by their distinctive internal characteristics: inclusions that are typical of both the flux-growth and the Verneuil processes. @chapter:9


Publication Year: 2013 Title: Spinel Submitted as Diamond Abstract: Figure 1. This rough spinel, submitted as a diamond, displayed trigons oriented in the direction opposite that of the crystal face. Photo by Joshua Balduf.

              Diamond simulants remain in wide circulation and are a common sight in the GIA laboratory. Even so, it is rare that we encounter a natural gemstone masquerading as a colored diamond. The New York laboratory recently received a 0.50 ct rough sample with a remarkably saturated Fancy Intense to Vivid pink color (figure 1) for a Colored Diamond Identification and Origin Report. The stone displayed octahedral crystal form with numerous trigons on its crystal faces. These triangular etch pits, caused by chemical dissolution, are common characteristics of both natural diamond and spinel but have also been observed in flux synthetic spinels (M.S. Krzemnicki, “Trade Alert: Flux grown synthetic red spinels again on the market,” SSEF Newsletter, October 14, 2008, p. 3). When found on octahedrons, trigons point in the direction opposite that of the crystal face (again, see figure 1). Figure 2 shows a distinctive conchoidal fracture amid the trigons, a feature alien to diamond. This feature, along with the sample’s striking color, indicated something other than diamond.

	Figure 2. In addition to trigons, the spinel displayed a conchoidal fracture (see arrow), a feature not found in diamond. Photomicrograph by Martha Altobelli; magnified 40x.
The high-resolution UV-Vis spectrum displayed emission bands and absorption peaks not seen in natural diamond. Closer examination of the photoluminescence spectrum affirmed chromium peaks at 685, 687, 689, and 700 nm. Chromium causes the red/pink color in spinel but is not present in diamond. The narrow bandwidth of the 685 nm peak, along with the presence of the ~533 nm band in the UV-Vis spectrum, proved this was an untreated stone (S. Saeseaw et. al., “Distinguishing heated spinels from unheated natural spinels and from synthetic spinels: A short review of on-going research,”  www.giathai.net/pdf/Heated_spinel_Identification_
at_May_25_2009.pdf). Other observations included a specific gravity of 3.45–3.48, consistent with spinel, as well as medium to strong red long-wave and short-wave UV. Though submitted for a diamond report, this stone was actually a natural pink spinel.

This finding serves as a reminder of the importance of both standard gemological techniques and advanced spectroscopy in identifying gem materials. @chapter:32


Publication Year: - Title: Brazil's Feninjer Jewelry Show Abstract: Brazil has become the sixth-largest economy in the world, and its growing consumer market is hungry for luxury products. To witness the rapid growth in the Brazilian jewelry industry, GIA ventured to the country’s main jewelry trade show.

	Feninjer Jewelry Show in Brazil @chapter:36


Publication Year: 2023 Title: Susan Jacques Receives Robert M. Shipley Award Abstract: Susan Jacques accepts the Robert M. Shipley Award at the American Gem Society’s 2023 Conclave in Louisville, Kentucky. Courtesy of AGS.
Susan Jacques, GIA’s president and CEO, has received the American Gem Society’s Robert M. Shipley Award, honoring her steadfast commitment to the jewelry industry. Named for the founder of GIA and AGS, the prestigious award was presented to Jacques at the AGS Conclave in Louisville, Kentucky, on May 2, 2023 (see above).
Jacques previously served as president and CEO of Borsheims in Omaha, Nebraska, one of the nation’s largest independent jewelry stores, where she reported directly to Warren Buffett. She served on GIA’s Board of Governors beginning in 1996 and held the chair position from 2008 to 2013 before her appointment as president and CEO in 2014. Jacques holds a Graduate Gemologist diploma from GIA and is a fellow of the Gemmological Association of Great Britain. She is the sixth recipient from GIA to win the award. @chapter:33


Publication Year: 2003 Title: G. Robert Crowningshield: A Legendary Gemologist Abstract: During his more than 50 years of involvement with the GIA Gem Laboratory, G. Robert (Bob) Crowningshield has made many significant contributions to the study of gems and the science of gemology. These include fundamental advances in the understanding and identification of treated and synthetic diamonds; of colored stones such as tanzanite, amethyst, “padparadscha” sapphire, and heat-treated corundum; and of natural and cultured pearls. In the early 1950s, Crowningshield demonstrated the value of new equipment in gem testing, in particular the spectroscope. He also helped develop and teach the GIA diamond grading system, now the standard worldwide. Along the way, he shared his wealth of practical experience in hundreds of articles, lectures, and industry presentations. All of these achievements helped lay the foundation of modern gemological research.

	DATA DEPOSITORY

Presentations at AGS Conclaves by G. Robert Crowningshield
	Submitted by Thomas M. Moses and James E. Shigley
	October 30, 2003 @chapter:29


Publication Year: 2017 Title: Moroccan Amethyst:Mining and Marketing Abstract: Figure 1. These amethyst crystals from Morocco show the strong zoning characteristic of stones from this location. Photo by Eric Welch/GIA, courtesy of Geostone Group.

	Characteristic “hourglass” color zoning (figure 1) and striking red hematite “finger” inclusions help distinguish Moroccan amethyst. Although amethyst is readily available on the market, the material from Boudi in southern Morocco stands out. While Moroccan amethyst has been featured in G&G previously (F. Troilo et al., “Amethyst from Boudi, Morocco,” Spring 2015, pp. 32–40), we gathered some fresh insights on the mine and the marketing strategy for this material from Alaeddine Rafei, who directs grading and sales for Geostone Group in Morocco.

	About 40 years ago, a group of nomads were stuck in a storm in the Anti-Atlas mountain range of southern Morocco. The next morning, they found purple crystals on the washed ground. The nomads kept bringing the crystals to tourist shops in the villages nearby. Seven years ago, a geologist and a cofounder of Geostone Group finally had the stones analyzed by GIA and confirmed that they are amethyst. Mining started in 2011–2012 and has continued on a small scale since then. From 2011 to 2015, the miners mainly used hand tools to remove the earth and extract the crystals. As the wall has gotten pushed further back, excavators have been used since 2015 to move earth. The miners are still hand picking crystals out of the removed earth.

	Rough amethyst crystals are transported to the company’s warehouse in Casablanca for washing and grading. Washing is done with water and acid. Rafei explained the four grades of Moroccan amethyst. The topmost grade consists of double-terminated single crystals, which are extremely rare. Rafei explained that only 1% of the production is gem quality (figure 2), of which only 2% are the double-terminated crystals. Next come the AAA grade, which refers to the deep purple stones, and the slightly less purple AA grade. The AA grade is the most common on the market. The fourth grade is a category called Rose du Maroc. Amethysts falling to this grade have an even lighter purple color than AA stones.

Figure 2. Morocco produces deep purple amethyst with red hematite “finger” inclusions that can cause red flashes of color. Photo by Eric Welch/GIA, courtesy of Geostone Group.

	Marketing these amethysts is an even greater challenge. As people can imagine, the rough amethyst market is very competitive, since there are many sources in different countries. In 2013, when Geostone’s founders brought their Moroccan amethysts to Tucson to test the market, they went home deflated by the feedback. Large colored stone cutting companies see little value in these amethysts. Luckily, the founders got connected with world-renowned gem carver Glenn Lehrer, who became their marketing advisor and took Moroccan amethyst in a completely different direction. Lehrer saw the unique features in these stones and applied his cutting styles and award-wining patented cuts to show off their beauty. The special cuts also better use the rough. The yield of Moroccan amethysts at a normal cutting factory is only about 8%. When Lehrer’s special cuts are applied, the yield was increase to an average of 20% for top-quality stones. He also introduced these amethysts to Gems TV. Instead of selling the rough to gem cutters, the company now offers faceted stones and finished amethyst jewelry directly to consumers through multiple TV programs in different countries.

	As a result, Moroccan amethyst is not just another amethyst. It is now a brand and trademark of Geostone Group. The mine-to-market story is sold with the gems. The story even landed Moroccan amethyst in the Rio Grande catalog. In return, the company is actively involved in community building in the mining area. It only hires local Berbers to work in the mine, offering them a good salary and health care. During the past several years, Geostone Group has kept production quite stable and limited mining crew sizes to around 20 people. Wells, roads, electricity, and designated vehicles for schoolchildren and villagers are all provided using profits from the amethyst mine. In 2016, Geostone Group received an award from the Moroccan government to highlight its contributions to social responsibility and gem mining in Morocco. @chapter:3


Publication Year: 2023 Title: New Violet Orbicular Chalcedony from Ethiopia Abstract: Figure 1. This relatively new type of violet chalcedony from Ethiopia (here, 75–198 ct) displays a wonderful pattern of white orbs. Photo by Annie Haynes; courtesy of Orbit Ethiopia Plc.
At the GJX show, the author encountered a relatively new find of violet chalcedony reportedly discovered in Ethiopia in 2019 (figure 1). Processed and brought to market as tumble-polished freeforms, the chalcedony was offered by Orbit Ethiopia Plc. According to managing director Tewodros Sintayehu, the mine is located in the Gamo Zone region, approximately 600 km from Addis Ababa. The material was first discovered in the Gerese District and has since been found in the adjacent districts of Kamba and Garda Marta. Sintayehu noted that he had a very large quantity of the material stockpiled.

Figure 2. White orb-like structures were confined to a shallow surface layer in the violet chalcedony from Ethiopia. Photomicrograph by Nathan Renfro; field of view 15.16 mm.
The notable features of this material were its fairly vivid violet color as well as the multitude of white orbicular structures distributed across the surface of the gems (figure 2). Microscopic examination revealed that the white color was related to a distinct botryoidal structure where a shallow outer layer of the gems contained all of the white areas. Because the white orbs are confined to a shallow surface layer, this explains why the material was sold as tumble-polished nuggets: Cutting the material into cabochons would likely result in the loss of the white orbicular pattern. A few unidentified mineral inclusions were also observed with the microscope, but the cause of the outer layer’s white orb pattern remains unclear.
This new material is quite remarkable for its beautiful pattern. Even if it is only made available as freeform tumble-polished stones, it will be a welcome addition to the chalcedony market. @chapter:5


Publication Year: 2018 Title: Book Review: Jewelry for Gentlemen Abstract: By James Sherwood, hardcover, 256 pp., illus., publ. by Thames & Hudson, New York, 2018, US$45.00.

Style icon Iris Apfel said, “Transformation, punch, individuality. One or all of the above are why you should wear jewelry.” Any fashion-alert gentleman will be emboldened to do so after perusing James Sherwood’s latest book, Jewelry for Gentlemen.
One of the most arresting aspects of the book is the author’s choice of exactingly illustrated brooches and pins on gentlemen’s blazers and jackets. Repeating that concept throughout the book gradually impresses upon the male reader “Yes, you can wear that.” A Fabergé openwork diamond bow brooch accenting the line of a lapel lessens the typically feminine aspect of the bow form. Expanding the premise of men’s jewelry is the dramatic photo of contemporary jewelry designer Shanu Leane’s Tahitian pearl “Thistle” brooch piercing a black satin lapel. Leane designed it for a dear friend, the late fashion designer Alexander McQueen—reinforcing the personal aspect of jewelry.
Sherwood judiciously quotes the designers featured in the book. The David Yurman section, represented by the powerful style of key creative leader (and David’s son) Evan Yurman, reflects the latter’s philosophy: “I think every man should embrace wearing jewelry in his daily life.” The power of the very presence of Evan Yurman’s pieces is illustrated by various collections. The force of the 18K yellow gold Forged Carbon cuff links along with photos of pieces in the “Shipwreck” collection—suggesting jewelry art as deep-sea sunken treasures—really does convey “transformation, punch, individuality.”
Jewelry houses such as Van Cleef & Arpels, Tiffany, Cartier, and Hemmerle are represented mainly with pins and brooches to reinforce the premise of going beyond the norms of rings, cuff links, bracelets, and chains. But Sherwood does honor these classic categories of gentlemen’s jewelry. He has chosen, with care, photos of elegant cuff links executed as sculptured gold forms in Verdura’s “Nut & Bolts” and Elsa Peretti’s “Golden Circle” cuff links.
The gemstone-set items in the high-quality photographs are eye-catching and inspiring. Donald Claflin’s “Aztec” brooch, a pair of Fabergé ruby and enamel cuff links, and a Lacloche Frères platinum and diamond brooch all cause the eye to linger on the pages.
The standard inclusion of a glossary and brief descriptions of design elements of jewelry style periods are appreciated and expected. These references lend a certain sturdy scholarly aspect to a beautiful book. Regrettably, Sherwood’s seeming fascination with gentlemen’s sexuality as revealed in jewelry choices or styles detracts from a nicely executed, precisely documented work.
Jewelry for Gentlemen serves as a memorable travelogue of style as interpreted in our oh-so-personal choices—perhaps a sentimental ring, a few chains, and a dapper pair of cuff links. @chapter:16


Publication Year: 2000 Title: Summer 2000 Gem News International Abstract: Diamonds
            New Diamond Cut: “Tycoon Cut”
            Diamond Presentations at the PDAC Conference
            Israel’s 2nd International Rough Diamond Conference
Colored Stones and Organic Materials
            Baltic Amber with Lizard Inclusion
            Ametrine with Layers of Smoky Quartz
            Bicolored Cat’s-Eye Beryl from Pakistan
            Natural Emerald and Quartz Intergrowth
            Update on Some Madagascar Gem Localities
            Freshwater Cultured “Kasumiga Pearls,” with Akoya Cultured Pearl Nuclei
            Trapiche Ruby: An Update
            Spinel from Ilakaka, Madagascar
Treatments
            Unusual Treated Chalcedony
Synthetics and Simulants
            Black Diamond Imitation
Announcements
            Tenth Annual Cutting Edge Awards
            The Dresden Green at the Smithsonian
            Gem 2000
            Mineralientage München
            Gemstones at Upcoming Scientific Meetings

To view the full section, download the PDF above. @chapter:0


Publication Year: - Title: Citrine Care and Cleaning Abstract: With proper care, citrine is a beautiful and versatile gemstone for jewelry use. – Robert Weldon

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

Common substances like sand and dust are composed mostly of quartz, the mineral species that includes the variety citrine. So, while citrine is a great gemstone for use in jewelry, it should be treated with the proper care to prevent scratching and other damage.

Citrine rates a 7 on the Mohs scale and has good toughness, so it is suitable for all jewelry types. This includes rings as long as the wearer understands its limited hardness.

	Citrine rates a 7 on the Mohs hardness scale. This means it’s durable for jewelry as
	long as proper precautions are followed to prevent scratching.
Stability
Abrupt temperature changes can cause citrine to fracture. Some citrine color can fade with prolonged exposure to intense light. Citrine can also be damaged by hydrofluoric acid, ammonium fluoride, and alkaline solutions.

Cleaning
Citrine can be safely cleaned with warm, soapy water. Ultrasonic cleaners are usually safe except in the rare instances where a stone is dyed or treated by fracture filling. Steam cleaning is not recommended, as citrine should not be subjected to heat. @chapter:29


Publication Year: 1984 Title: Summer 1984 G&G Lab Notes Abstract: Amethyst with Unusual Natural Inclusion
Cummingtonite-Grunerite, a Series in the Amphibole Group
Coated Diamonds
Dendrite-Like Inclusion in Diamond
Diopside
Artistically Stained Nephrite
Dyed Nephrite
Imitation Mabe Pearls
Unusual Cultured Pearls
Unusually Large Multi-Star Quartz
Heat Treated Ruby
Verneuil Synthetic Sapphire
Black Spinel
Cat's-Eye Zircon

To view the full section, download the PDF above. @chapter:17


Publication Year: 2023 Title: Mining Basalt-Related Gems in Southeast Vietnam Abstract: Figure 1. Gem materials from southeast Vietnam. The three largest yellow and white samples on the far left are feldspar, while the brown, orange, and near-colorless samples in the center are zircon and the two greenish white samples near the top right are hyalite opal. The rest of the dark stones are sapphires, garnets, augites, and brown peridot. Photo by Le Ngoc Nang; courtesy of Tran Ngoc Vien.
A number of gemstone deposits are known in provinces all across Vietnam. These include ruby (Yen Bai and Nghe An), sapphire (Yen Bai, Nghe An, Binh Thuan, and Dak Nong), spinel (Yen Bai and the Central Highlands), aquamarine (Thanh Hoa and Khanh Hoa), tourmaline and garnet (Yen Bai), and peridot (Gia Lai). Recently, seven gemstone occurrences have been identified within the basaltic fields in southeast Vietnam, which are mainly found in Dong Nai and Ba Ria–Vung Tau provinces. These gems include sapphire, zircon, garnet, augite, brown peridot, feldspar, and hyalite opal. They are found predominantly in basalt bedrock and its regolith as xenocrysts or xenoliths deposited on hillslopes or in placer formations along streambeds. Seven gemstone species from southeast Vietnam were collected and documented (figure 1).
The sapphires usually appeared as hexagonal crystals or fragments, exhibiting mainly blue, deep to dark greenish blue, and greenish yellow colors. Most were transparent to semitranslucent and some opaque, and the luster was greasy to vitreous. The typical rough sizes ranged from 5 to 20 mm, weighing 2–10 ct.

Figure 2. Basalt-hosted gem materials from southeast Vietnam: A subhedral zircon crystal in laterite (A), a garnet xenocryst in basalt (B), and a brown peridot nodule in basalt (C). Photos by Le Ngoc Nang.
Euhedral tetragonal crystals of zircon were very common, while the rest of them were fragmented. Colors included orange, brown-red, gray, and colorless. These zircon samples showed high luster ranging from adamantine to vitreous, with a transparent to semitransparent appearance. Zircons from southeast Vietnam were not found in fresh basalt; they were found mostly in placer and in weathered basalt instead (figure 2A).
“Red stone” is a local name for gem-quality garnet from Dong Nai. The garnets occurred in two forms of anhedral fragments: xenocrystic fragments (also called “orphan stone”) weighing 1–50 ct, with a corroded surface, and xenolith-hosted garnet containing small corroded fragments that produce 1–5 ct fashioned gems. Both xenocryst (figure 2B) and xenolith-hosted garnet were found mainly in the regolith on the hillslopes. The color ranged from deep to dark red and occasionally deep orangy yellow, with a transparent to semitransparent quality and a vitreous luster.
Euhedral crystals of Dong Nai feldspar were characterized by two directions of perfect cleavage. These feldspars were colorless, gray, and rarely light yellow, with a vitreous luster and a transparent to translucent appearance. This mineral was the most common gem material in the region and could be found in both bedrock and its regolith.
As reported recently, the augite samples appeared black under daylight-equivalent illumination but displayed green and brown colors under transmitted light. Most samples were transparent to translucent and had vitreous luster. The brown gems tended to be more transparent than the green ones (L.N. Nang et al., “Gem-quality augite from Dong Nai, Vietnam,” Summer 2023 G&G, pp. 182–194).
Brown peridot was found as slightly corroded xenocrystic fragments measuring 0.5–5 cm. The samples were black under reflected light but greenish yellow-brown with transmitted light. Most samples were transparent to translucent, with a vitreous luster. The brown peridot was quite rare and frequently confused with augite due to their similar morphology and occurrence in the vesicular basalt (figure 2C).
The hyalite opal was found in Ba Ria–Vung Tau, and each sample consisted of two parts: the inner body and the outer layer. The contact between the two parts was distinct. The outer layer was opaque white, 2–5 mm thick, and porous. The inner body was usually colorless and rarely green, brown, or light pink, transparent to opaque, with a vitreous appearance. The hyalite opals with good transparency were suitable for jewelry due to their glowing green fluorescence under long-wave ultraviolet light (weak fluorescence under short-wave UV).
Several of these gem deposits in southeast Vietnam are unlicensed. Most materials were collected by locals using artisanal methods, without any commercial mining. The gem materials found along hillslopes or stream channels were extracted at shallow depths ranging from 0.3 to 0.5 m. The gems appeared more frequently after rain and were distributed by their specific gravity. For instance, light material such as hyalite opal was concentrated on the hilltop, stored in slightly weathered and broken-up rock, while heavier minerals, namely sapphire, garnet, feldspar, and peridot, usually accumulated along the hillslopes. Zircon, on the other hand, was often deposited in streambeds. Some gems stored in basalt were extracted easily by homemade tools.
Most of the rough materials are sold to gem dealers in Ho Chi Minh City, who sell fashioned products to local markets in southeast Vietnam. Gemstones in the area have long been gathered by locals during farming and well drilling, but the old-fashioned mining methods led to a significant waste of gem resources. Preliminary evaluations of gem quality have shown that gemstones from southeast Vietnam are of economic potential. The thick basaltic host rock covering a large area is a foundation for prospecting numerous gem materials and requires further research to comprehensively assess available reserves. @chapter:3


Publication Year: - Title: Diamond Digging in Ghana Abstract: Artisanal miners work a deposit near Ghana's Birim River.

                      Akwatia, Ghana, is a town built by diamonds. Rows of low, corrugated rooftops branch out from the old town center. On the outskirts, where the small-scale farms begin, an occasional mansion rises beside the highway. Some of these mansions are owned by the lucky ones—diggers who found a cache of large diamonds. Most belong to the concession holders who take a cut from the finds of the galamsey, the local name for artisanal diggers who work the river banks.

A half century ago, Akwatia was one of the most productive diamond spots on the planet. Diamonds were discovered at the nearby Birim River in 1920, when the nation was a British colony called the Gold Coast. By the end of that decade, production neared a million carats yearly, doubling by 1935.

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The Birim River remained one of the world’s most productive sources through Ghana’s independence in 1957, until the late 1970s when the richest areas were mined out and the aging mining equipment was unable to efficiently process smaller, lower-quality stones. Today, that is most of what the artisanal diggers recover: Of the 301,000 carats mined and exported each year, the vast majority are darker stones smaller than 0.10 ct.

	A diamond buyer sorts the finds of a local miner.
In the late 1980s, the government allowed the small-scale miners to work areas along the 40-mile diamond-bearing stretch of the Birim River, an area unsuitable for mechanized mining. While some miners have registered, in compliance with government requirements, about 75% have not.

In 2012, an investor group announced a $100 million plan to revive mechanized mining at Birim River. Still, the government and investors have pledged to maintain concessions for the artisanal diggers who now sustain the economic life of the region. @chapter:28


Publication Year: 1983 Title: The Capão Topaz Deposit, Ouro Preto, Minas Gerais, Brazil Abstract: For over 200 years, the only known source of imperial topaz has been a small mining district near Ouro Preto. One of the oldest and most productive mines in the district is the Capão do Lana. This article examines the history of the Ouro Preto district as well as the geology of the area and occurrence of the topaz. Special attention is focused on the relatively sophisticated recovery methods used at the Capão do Lana mine. Also discussed is the gemology of this most prized color variety of topaz. @chapter:3


Publication Year: 2018 Title: Meeting of the International Mineralogical Association Abstract: The 22nd meeting of the International Mineralogical Association (IMA), the first held in Australia and only the second in the Southern Hemisphere, took place in the Melbourne Convention and Exhibition Centre August 13–17, 2018. The meeting was hosted by the Geological Society of Australia.
Two technical sessions on gems were presented to about 100 attendees. The August 13 session, “Sciences Behind Gemstone Treatments,” was chaired by Andy Shen (China University of Geosciences, Wuhan) and Pornsawat Wathanakul (Gem and Jewelry Institute of Thailand). The second day’s session, titled “Recent Advances in Our Understanding of Gem Minerals” and led by Ian Graham (University of New South Wales, Australia), Lee Groat (University of British Columbia, Canada), and Gaston Giuliani (University of Lorraine, France), is detailed below.
The session consisted of 18 oral presentations covering several gem topics. Frederick Sutherland (Australian Museum, Sydney) opened with a keynote talk on the diversity in the geochemistry and inclusions of ruby from Myanmar and eastern Australia. He also discussed the ages of ruby formation through zircon ages and the P-T conditions through inclusion assemblages.
The other talks concerned different types of gems from supergene minerals up to corundum and spinel, including mining discoveries and activities from ancient and modern ages. Ruslan Kostov (Sofia University of Mining and Geology, Bulgaria) presented the archeological mineralogy of the Balkans through prehistoric (7 to 5 million BCE) gem minerals (nephrite, jadeite, talc, gabbros, jasper, and turquoise) and gold. Lee Groat revealed recent advances in colored gemstones in Canada, focusing on emerald from Yukon and blue spinel, sapphire, and scapolite from Baffin Island, as well as the use of different techniques such as drones for exploration. Peter Lyckberg (Luxembourg) offered a detailed state-of-the art presentation on the mining of gem pegmatites in Afghanistan and Pakistan, with amazing photos of aquamarine, kunzite, indicolite, and spessartine crystals from deposits in the High Karakoram range. Wim Vertriest (GIA, Bangkok) discussed the dynamics of gemstone discoveries and the challenges for research on the basis of timing the life of a deposit and the market perception of the gems’ quality.
Different techniques for source determination of gems were also presented. Hao Wang (SSEF, Basel, Switzerland) related the advances in origin determination for gems using inductively coupled plasma time-of-flight (ICP-TOF) spectroscopy, with applications for blue sapphires and emeralds. Zhiqing Zhang (China University of Geosciences, Wuhan) used Fourier-transform infrared (FTIR) characteristics of amber from different areas of the world for origin determination. Allan Pring (Flinders University, Adelaide, Australia) related the use of multiple techniques on 200 opal samples of various origins, showing their similarities and differences. Kemela Wijayanti (Padjadjaran University, Indonesia) combined petrographic analysis with scanning electron microscopy (SEM) and X-ray fluorescence (XRF) techniques to characterize green jasper from southern Java. Peter Downes (Western Australian Museum, Perth) applied multiple techniques on variscite and associated phosphate minerals from the Mt. Deverell deposits in the Gascoyne region of Western Australia. Isabella Pignatelli (University of Lorraine) reported on the use of electron microprobe analysis, SEM, and X-ray tomographic images for characterizing trapiche ruby from Luc Yen in northern Vietnam.
New studies combining fieldwork with mineralogy and geochemistry were presented for several types of gems. Philippe Belley (University of British Columbia) discussed advances in trace-element fingerprinting for blue spinel and new insights into the origin of cobalt-blue spinel from Baffin Island in Canada. This author gave an update on gem demantoid garnet from Madagascar’s Antetezambato deposit, based on new field data, and geochemical analysis of the most important demantoid deposits worldwide. Simon Pecover (Pan Gem Resources) coupled tectonic, hydrodynamic, rheologic, and shear-induced crystallization processes in the formation of opal veins in Australia, showing that the genetic model for the formation of Australian opal is more complex than previously known. Ahmadjan Abduriyim (Tokyo Gem Science) used the U/Pb method on zircon inclusions for determining the formation ages of sapphires from the New England fields in New South Wales. Kandy Wang (University of New South Wales) presented data obtained on ruby from Paranesti, Greece, specifying the geographic typing of ruby via oxygen isotopes and trace elements. Nick Raffan, also of the University of New South Wales, combined fieldwork with remote sensing, petrographic analysis, and SEM to decipher the source of sapphires near tertiary volcanic plugs and Devonian conglomerates from Tomahawk Creek in central Queensland. Ian Graham related the presence of unusual alluvial sapphires from Orosmayo in Argentina using a multi-analytical approach to uncover their origin.
This session was followed by an evening meeting at the Gemmological Association of Australia (GAA) House in Melbourne, under the direction of Margaret Blood, president of the GAA’s Victorian Division, and organized by Andy Shen and Pornsawat Wathanakul. The meeting was open to all researchers who participated in the two gem sessions of IMA and to Australian gemologists. The meeting consisted of three hour-long talks by this author on Colombian emeralds, Lee Groat on spinel and sapphire from Baffin Island, and Brendan Laurs (Journal of Gemmology) on pegmatites of Namibia. @chapter:1


Publication Year: 2017 Title: Ethiopian Precious Opal with a Dyed Brown Bodycolor Abstract: Figure 1. A 17.15 ct brown dyed precious opal from Ethiopia (left). The back of the stone was almost white, which suggests that it had been repolished after dyeing (right). Photos by Robison McMurtry.
Brown opal exhibiting play-of-color has been previously reported (M.L. Johnson et al., “Opal from Shewa Province, Ethiopia,” Summer 1996 G&G, pp. 112–120) and can occasionally be found in the marketplace as “chocolate opal.”

Recently, a 17.15 ct semi-transparent oval cabochon with brown bodycolor and strong play-of-color (figure 1, left) was submitted to the Carlsbad laboratory for identification services. Basic gemological observation and properties confirmed that the stone was opal. The spot refractive index was 1.41. The opal displayed hydrophane behavior by absorbing water, which was easily observed during microscopic examination (Fall 2013 Lab Notes, pp. 175–176).

While this specimen’s properties were consistent with Ethiopian opal with a natural brown bodycolor, it was necessary to confirm that the color was not the result of dye, since this was hydrophane-type material (N. Renfro and S.F. McClure, “Dyed purple hydrophane opal,” Winter 2011 G&G, pp. 260–270). Meticulous examination showed that the brown color conformed to the surface, indicating that it was in fact the result of dyeing after the stone had been fashioned. The uneven bodycolor was difficult to detect because of the stone’s transparency and strong play-of-color. Careful microscopic examination with strong transmitted and diffused white lighting revealed very subtle color concentrations in pits and uneven blotchy brown patches on the surface (figure 2), which confirmed that the brown color was artificially induced. Interestingly, the back of the stone was almost white in the center and brown along the edge (see figure 1, right), showing clear surface-conformal brown color. This suggests that the back of the stone was repolished after dyeing, which would have removed the dark brown rind in the process.

Figure 2. Uneven color is observed with the help of strong transmitted and diffused lighting; the blotchy darker brownish area is the result of dyeing. Photo by Jonathan Muyal; field of view 3.57 mm.
On the brown side, the opal showed an unusual chalky greenish yellow color when examined under long-wave UV light, possibly due to the dye. Advanced gemological analysis with Raman spectroscopy revealed a natural opal spectrum that was free of any peaks pertaining to foreign substances. Energy-dispersive X-ray fluorescence (EDXRF) did not detect manganese, which is the cause of brown color in Ethiopian opal.

Although dyed opal is often easy to identify, this brown dye looked natural, and the color of the stone did not change after hydrophane testing. While the dye was difficult to detect on the top surface of this stone, its back fortunately appeared to have been repolished, offering additional evidence of dye. When examining opal, it is important to consider carefully whether it could be dyed, especially if it is hydrophane material with a color that occurs naturally. @chapter:39


Publication Year: 2024 Title: Trigon Party on a Diamond Abstract: A collection of trigons on the pavilion surface of a round brilliant-cut diamond. Photomicrograph by Isabelle Corvin; field of view approximately 2.0 mm.
Triangular-shaped markings known as trigons are common in natural diamond. These “birthmarks” formed during growth are signs of a diamond’s ancient origin deep within the earth. The trigons in the figure above form a striking cluster on the faceted girdle and extend into two of the lower girdle facets of a 1.01 ct natural diamond. Even through the cutting and polishing process, these trigons remained on the surface.
Although trigons are not exceedingly rare, the assortment of this many trigons grouped together provides a remarkable portrait created by Mother Nature. The perfection of a diamond is on full display in the angles, luster, and alignment of each trigon. @chapter:31


Publication Year: 1991 Title: Bohemian Garnet – Today Abstract: Red garnets have been mined in the Bohemian Hills of Czechoslovakia since the 16th century. These pyrope garnets reached their height of popularity in jewelry of the Victorian era. Although the deposits had been generally regarded as depleted, today a small mining operation is working on garnetiferous gravels near the village of Podsedice, northwest of Prague. @chapter:1


Publication Year: 2021 Title: Bent Rutile in Rock Crystal Quartz Abstract: Figure 1. Brownish red “bent” rutile with additional orangy needles displaying sagenitic twinning. Photomicrograph by Nathan Renfro; field of view 11.28 mm. Courtesy of Mike Bowers.

The authors recently examined a polished quartz disk with an unusual rutile (TiO2) inclusion (figure 1). Although rutile in quartz is reasonably common and has been well documented, this “bent” rutile was a fun oddity as it also contained small orangy sagenitic twinned rutile needles extending from the primary bend in the rutile needle. Rutile is most often seen as fine, straight needles (E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Vol. 2, 2005, Opinio-Verlag Publishers, Basel, Switzerland, pp. 627 and 630). Rutile can play many roles as an inclusion and may contribute to phenomenal effects as well as to the bodycolor of an overall transparent colorless quartz (figure 2). While the exact cause of the bent nature of this rutile inclusion is unknown, the stone is a fascinating example of the unusual formation of inclusions in gems.

Figure 2. The polished transparent rock crystal quartz containing the bent rutile inclusion. Photo by Robert Weldon. @chapter:19


Publication Year: 2021 Title: Faceted Octahedral Diamond with Octahedral-Shaped Inclusion Abstract: Figure 1. This natural 2.01 ct Fancy Light brownish greenish yellow diamond octahedron was faceted to highlight an octahedral-shaped cloud inclusion. Photo by Nathan Renfro.

Recently, the authors examined a 2.01 ct faceted diamond octahedron (6.28 × 5.98 × 7.14 mm) with a Fancy Light brownish greenish yellow color grade that showed a distinctive internal appearance (figure 1). Microscopic examination revealed an octahedral-shaped inclusion scene composed of minute inclusions and clouds. The faceting arrangement of the diamond was likely meant to highlight the octahedron.

Figure 2. The faceting pattern for this diamond includes four hexagonal facets that provide a window of the octahedral-shaped inclusion. From this viewing angle, the octahedron resembles a six-pointed star. Photomicrograph by Nathan Renfro; field of view 4.69 mm.

	Faceted Octahedral Diamond with Octahedral-Shaped Inclusion

Viewed from one perspective, the hexagonal facet shows the internal octahedron in such a way that the inclusion scene resembles a six-pointed star (e.g., figure 2; see the video). Similar octahedral-shaped inclusions have been encountered before in natural diamonds (Winter 2015 Lab Notes, pp. 428–429; Spring 2011 Lab Notes, pp. 50–52).

Figure 3. This detail of one of the octahedron’s vertices indicates that the cloud comprises small inclusions. The portion of the octahedral cloud closest to the vertex within this image has a depth of approximately 1.8 mm below the hexagonal-shaped facet. Photomicrograph by Sally Eaton-Magaña; field of view 1.50 mm.
Oftentimes, such symmetrical clouds are dark-colored or gray (W. Wang and W. Mayerson, “Symmetrical clouds in diamond—The hydrogen connection,” Journal of Gemmology, Vol. 28, No. 3, 2002, pp. 143–152). These can also contain evidence of hydrogen, nickel-related defects, or graphite (S. Eaton-Magaña et al., “Inclusion and point defect characteristics of Marange,” Diamond and Related Materials, Vol. 71, 2016, pp. 20–29). At higher magnification, the individual inclusions that combine to create the cloud can be seen (figure 3).
The cloud inclusion resulted in an SI1 clarity grade. The diamond exhibited no fluorescence to long-wave UV and blue N3-related fluorescence within the diamond when exposed to the deep UV within the DiamondView. The cloud inclusion itself showed no distinctive fluorescence compared to the rest of the diamond. The IR absorption spectrum indicated the presence of strong nitrogen aggregates and a strong hydrogen peak at 3107 cm–1 associated with the N3VH defect. The visible/near-infrared absorption spectrum contained typical cape features and a hydrogen-related band at 835 nm. The hydrogen features detected in the IR and Vis-NIR absorption spectra correspond with the presence of the octahedral cloud inclusion.

Figure 4. Left: This false-color PL map was compiled from thousands of spectra (each pixel is 15 microns in size) and plots the intensity of a peak centered at 694 nm (associated with nickel and often seen in hydrogen clouds). The detection of this peak corresponds well with the hydrogen cloud. The data were collected with 532 nm excitation at liquid nitrogen temperature, and the peak intensity is normalized by ratioing to the diamond Raman peak. Right: These two spectra were collected from a “red” and “blue” portion of the PL map. The diamond Raman areas are scaled equally. The cloud inclusions indicated elevated concentrations of peaks that include those at 694 and 700.5 nm; outside of the inclusion, there are increased concentrations of NV– at 637 nm.
Spectroscopically, the most interesting results came from photoluminescence (PL) mapping of the octahedral-shaped cloud inclusion. This was performed at liquid nitrogen temperature using 532 and 455 nm excitations. Using 532 nm excitation, we saw elevated concentrations of peaks at 694 and 700.5 nm within the cloud inclusion (figure 4). The elevated concentrations of these peaks are consistent with previously characterized hydrogen clouds (e.g., Fall 2020 Lab Notes, pp. 416–419). The 694 and 700.5 nm peaks are ascribed to nickel and are often seen in hydrogen-rich diamonds (K. Iakoubovskii and G.J. Adriaenssens, “Optical characterization of natural Argyle diamonds,” Diamond and Related Materials, Vol. 11, No. 1, 2002, pp. 125–131). In the 455 nm PL mapping, a nickel-nitrogen-related defect at 496.7 nm called the S3 center (T. Hainschwang et al., “The Rhodesian Star: An exceptional asteriated diamond,” Journal of Gemmology, Vol. 34, No. 4, 2014, pp. 306–315) was also detected within the cloud. Outside of the inclusion, we detected higher concentrations of the NV– defect (principal emission at 637 nm).
While the faceting pattern dramatically highlights the octahedral-shaped inclusion to resemble a six-pointed star, the cloud is not confined to a narrow focal plane as it might appear in figures 1 and 2. Instead, the cloud spans throughout much of the volume of the faceted stone. Creative faceting by the polisher provides a unique perspective on the cloud inclusion that makes this unusual diamond even more memorable. @chapter:11


Publication Year: 2023 Title: Heart-Shaped Golden South Sea Cultured Pearl Abstract: Figure 1. A heart-shaped golden South Sea pearl pendant measuring 17.78 × 11.65 × 9.07 mm and weighing 1.93 g (including the 18K yellow metal findings). Photo by Sood Oil (Judy) Chia.
The heart shape has been a worldwide symbol of love and romance for centuries. GIA’s New York laboratory recently received a golden-colored heart-shaped pearl pendant that drew our attention. The pearl was reportedly produced in the Philippines, which is a major source of golden South Sea cultured pearls. Upon routine gemological and advanced instrumental examination—including microradiography, ultraviolet/visible spectroscopy, manganese and strontium contents from energy-dispersive X-ray fluorescence, and reaction to long-wave UV—we concluded that it was an atypical bead cultured pearl from the Pinctada maxima species, commonly known in the trade as a South Sea cultured pearl (figure 1), and its heart shape and golden color were entirely natural.

Figure 2. X-ray images from RTX (left) and CT (right) show the demarcation of a heart-shaped bead nucleus with an average nacre thickness of 0.80 mm.
Unlike the traditional bead cultured pearls typically nucleated with spherical shell bead nuclei, a heart-shaped bead nucleus was used in this pearl to achieve its unique shape. Hence, it was described as an “atypical bead” cultured pearl (aBCP) according to GIA’s pearl identification terminology. Real-time microradiography (RTX) and X-ray computed microtomography (CT) clearly revealed the internal structure of a heart-shaped bead nucleus (figure 2). The nacre coverage, averaging 0.80 mm thick, was evenly distributed all around the nucleus, demonstrating that the heart shape of the pearl was consistent with the shape of the nucleus. Magnification revealed no signs of surface working or treatment, suggesting the pearl was in its original form after harvest. It displayed a strong orangy yellow color that is highly sought after among South Sea pearls. Ultraviolet/visible reflectance and photoluminescence spectroscopy further confirmed its natural color origin (C. Zhou et al., “Update on the identification of dye treatment in yellow or ‘golden’ cultured pearls,” Winter 2012 G&G, pp. 284–291).
Although this was not the first time a heart-shaped pearl has been examined in the lab, it is very rare to see a whole pearl with such a perfect non-round cultured shape. Previous submissions have either been identified as mabe pearls (assembled cultured blisters) or have had poorly defined heart shapes. Mabe pearls are not considered whole pearls and often possess a thin nacre dome top (Fall 2021 Gem News International, pp. 277–279). Due to the thin nacre, their shape is easier to control. Therefore, fancy-shaped nuclei are commonly used in mabe pearls.
Many atypical bead cultured pearls have been studied and examined over the years at GIA (“Atypical ‘beading’ in the production of cultured pearls from Australian Pinctada maxima,” GIA Research News, February 13, 2017; Fall 2022 Gem News International, pp. 378–380). However, the majority of the end products are very different from the original shape of the nuclei. This remarkable use of an atypical bead nucleus to achieve a perfect shape in a cultured pearl suggests recent improvements in pearl culturing techniques. @chapter:14


Publication Year: 1983 Title: Spring 1983 G&G Lab Notes Abstract: Cat's-Eye Alexandrite
Carved Diamond
Pink Diamonds
Imitation Emerald
Tubules in Emerald
Fluorite and Rose Quartz Necklace
Garnet and Glass Doublets
Cat's-Eye Opal
Treated Opal
Paleontological Gemology
Cultured Button Pearls
Pearl Mysteries
A Rare Cat's-Eye Quartz
Ruby and Synthetic Ruby Assembled Stone
Spinel with Color Change
Unclassified Oddities

To view the full section, download the PDF above. @chapter:2


Publication Year: 2023 Title: Guest in Garnet: Metal Sulfide? Abstract: An opaque crystal, likely a metal sulfide, is suspended in a garnet. A combination of darkfield and oblique fiber-optic illumination makes it appear as though the crystal is hovering inside the stone. Portions of the inclusion are duplicated because of its split across several facet junctions, adding to the visual interest. Photomicrograph by E. Billie Hughes; field of view 4 mm.
Recently a faceted garnet containing a striking inclusion came across the author’s desk. The solid inclusion was opaque with a metallic luster and had an uneven surface containing numerous sharp protrusions (see above). Although we were unable to definitively identify the inclusion, its opaque dark nature and crenulated texture were consistent with a metal sulfide crystal.
This inclusion scene inspired a variety of imaginative comparisons at our laboratory. Some thought it was reminiscent of the fire-breathing piranha plants from the Super Mario franchise, while others suggested it resembled a Ferrero Rocher chocolate. Regardless of what we might see in this piece, it is certain that we will continue to be fascinated by the delightful whimsy of Mother Nature’s micro-world. @chapter:19


Publication Year: 1997 Title: Multicolored Bismuth-bearing Tourmaline from Lundazi, Zambia Abstract: Tourmalines from an alluvial deposit near Lundazi in Zambia consist of color zoned pink/colorless/yellow-green “watermelon” nodules; many fashioned stones contain patches and blends of all three colors. Although these elbaite tourmalines are unusually rich in bismuth (up to 0.49 wt. % Bi2O3), the presence of bismuth apparently has no effect on their gemological properties. Approximately 10,000 carats of fashioned stones are known to have been produced from October 1996 to mid-1997. @chapter:5


Publication Year: 2021 Title: Historic Sales of Pink and Blue Diamonds from the Argyle Mine Abstract: Figure 1. Five diamonds that headlined the final Argyle pink diamond tender, titled “The Journey Beyond.” Courtesy of Rio Tinto.
In October 2021, nearly one year after the end of operations at the Argyle mine in Western Australia, Rio Tinto sold its final production of pink and blue diamonds. The company announced that the 37th Argyle pink diamond tender collection of 70 rare pink and red diamonds delivered record-breaking prices across individual diamonds and for the overall collection. This year’s edition was conducted in a series of virtual and face-to-face viewings. Highlights from the sale (shown left to right in figure 1) were the 2.03 ct Fancy Deep pink Argyle Lumiere, the 1.79 ct Fancy Vivid purplish pink Argyle Stella, the 2.05 ct Fancy Intense pink Argyle Solaris, the 3.47 ct Fancy Intense pink Argyle Eclipse, and the 1.01 ct Fancy red Argyle Bohème. (For more on Argyle’s pink diamond sales, see J.M. King et al., “Exceptional pink to red diamonds: A celebration of the 30th Argyle diamond tender,” Winter 2014 G&G, pp. 268–279.)

Figure 2. A selection of blue and violet diamonds from Rio Tinto’s “Once in a Blue Moon” tender. Courtesy of Rio Tinto.
Along with the pink diamond tender, Rio Tinto sold its final collection of Argyle blue and violet diamonds (figure 2), which the mine has produced sporadically over the years (see C.H. van der Bogert et al., “Gray-to-blue-to-violet hydrogen-rich diamonds from the Argyle mine, Australia,” Spring 2009 G&G, pp. 20–37). The entire lot of 41 diamonds totaling 24.88 carats was purchased by a single bidder. @chapter:38


Publication Year: 2018 Title: Exhibition Review: Ornamental Traditions: Jewelry from Bukhara Abstract: Figure 1. Paisley earrings ca. 1885. Gilt silver with cloisonné enamel. Promised gift of Barbara and David Kipper. Photo courtesy of the Art Institute of Chicago.

The Uzbek city of Bukhara, the last capital of the Emirate of Bukhara (1785–1920), was designated a UNESCO World Heritage site in 1993. Situated along the famous transcontinental Silk Road, the city is known for its architecture, particularly the blue glazed tiles and complementary blue enamelwork that grace its buildings. This same blue ornamentation is worked into the jewelry from this period of Bukhara’s history. The large pieces that characterize the jewelry of the emirate, stunning in their elaborate ornamentation, are rarely seen outside the former Soviet republics. Through promised gifts from the private collection of Barbara Levy Kipper and her late husband, David, the Art Institute of Chicago is able to display almost 50 such pieces in Ornamental Traditions: Jewelry from Bukhara. Enameling is used in a number of objects—such as the paisley earrings in figure 1—to represent Bukhara’s famous blue detailing with great success, while other pieces use turquoise and glass stones (figure 2) to create a similar effect.

Figure 2. Pair of armbands, ca. late nineteenth century. Silver inlaid with turquoise and glass stones. Promised gifts of Barbara and David Kipper. Photos courtesy of the Art Institute of Chicago.
In Bukharan culture, large jewelry pieces were normally designed as sets and intended to serve multiple purposes. For instance, the pieces of one suite might be intended to ward off evil spirits while simultaneously indicating political status and religious affiliation. There is no shortage of objects devoted to religious observation; one, a Quran carrying case dating from the late nineteenth century (figure 3), includes a strap for portability. The entire piece is made of gilt silver, cloisonné enamel, and leather. A set of pendants feature turquoise, coral, and glass stones inlaid in silver. Silver (both pure and gilded) is the primary metal in the pieces on display. This is understandable given the weight of large belts and elaborately decorated headdresses, such as one ceremonial piece featuring ruby, coral, and glass. Gold is occasionally seen in objects from the late nineteenth century, such as a pair of earrings designed in the Gujarati akota style. Decorative objects such as a twentieth-century pen case (figure 4) and an enameled box dating to 1883 (figure 5) are no less fantastic in their attention to detail and functionality.

Figure 3. Quran carrying case ca. 1890–91. Gilt silver with cloisonné enamel and leather. Promised gift of Barbara and David Kipper. Photo courtesy of the Art Institute of Chicago

Figure 4. Pen case ca. 1912, inscribed “A.H. 1330.” Gilt silver with cloisonné enamel. Promised gifts of Barbara and David Kipper. Photos courtesy of the Art Institute of Chicago.
Juxtaposed alongside Central Asian textiles—some created using the elaborate ikat resist dyeing technique—from the Art Institute’s permanent collection, Ornamental Treasures is a small but powerful view into a bygone world rarely seen by Westerners.

Figure 5. Enameled box ca. 1883. Silver with cloisonné enamel. Promised gifts of Barbara and David Kipper. Photos courtesy of the Art Institute of Chicago.
Ornamental Traditions: Jewelry from Bukhara is on view in Gallery 50 of the Islamic Art section of the Art Institute of Chicago until June 30, 2019. Admission is $20.00 for Chicago residents, $22.00 for Illinois residents, and $25.00 for visitors from out of state. Senior and student pricing begins at $14.00. Children 17 and under qualify for free admission. The Art Institute of Chicago is open daily from 10:30 a.m. to 5:00 p.m. and Thursdays until 8:00 p.m. @chapter:21


Publication Year: 2016 Title: Exhibition Review: Illuminations, from Earth to Jewel Abstract: Figure 1. Jessie brooch. Yellow gold, pink and yellow sapphire, diamond, and peridot. Photo courtesy of Paula Crevoshay.

For more than 33 years, American jewelry artist Paula Crevoshay has been known her ability to mix unusual and rare gemstones into impressive and colorful jewels as brooches, earrings and cocktail rings. She is known in the jewelry industry as the “Queen of Color” because of her work. This fall, the Museum of Mineralogy at the ParisTech School of Mines exhibited Illuminations, from Earth to Jewel, where select pieces of Crevoshay’s impressive contemporary jewelry was displayed alongside the museum’s specimen collection. The exhibition offers a dazzling tribute to nature, Crevoshay’s favorite source of inspiration. It highlights gems rarely used by French jewelers, such as apatite, chrysocolla, spinel, and atypical garnets.

A former painter, Crevoshay approaches each piece like a painting, combining techniques and choosing gems to create shades than our eyes will perceive as striking in her bugs, leaves, and landscapes. Five display cases invite the visitor to admire a selection of thirty-two jewels, culled from private collections. These include orchid-inspired pieces, marine animals, and abstract creations. It’s difficult for this reviewer to select favorite pieces from the show. Two impressive flower brooches, Jessie and Maia’s Gift are notable for their colorful contrasts. The mix of pink and yellow sapphires with peridots in the former (figure 1) and tsavorite garnets, pink and yellow sapphires, and diamonds in the latter (figure 2) make these two pieces stand out. These mix of bright, pure color mixtures are far from traditional, but they ultimately work. The result is bold and joyful. And Crevoshay shows her audience how important and innovative it is to make unexpected choices outside of diamonds and the classic “Big Three” of sapphire, ruby, and emerald, as in her Tsaritsa earrings (figure 3). These feature azurite-malachite cabochons as center stones accentuated by tsavorites.

Figure 2. Maia’s Gift brooch. Yellow gold, tsavorite garnet, pink and yellow sapphire, and
diamond. Photo courtesy of Paula Crevoshay.

Figure 3. Tsaritsa earrings. Yellow gold, opal, tsavorite garnet, and azurite/malachite.
Photo courtesy of Paula Crevoshay.
By providing two rough specimens from the collection per piece, the conservation team of the Museum allows the public to gain a better comprehension of the relationship between mining, cutting, and setting. It’s the perfect place to see how crystallized minerals or gemstones and imagine how gem cutters will give sparkle to the final stones.

Crevoshay’s next vision is to translate into jewelry the origins of the gems used, in order to create beautiful masterpieces that will reflect the gems found in these locations. It’s possible that the bracelet Rainbow over Montana (figure 4) is from this new chapter. This piece enhances all the range of colors found in Montana sapphires, from a strong blue to a greenish grey, along with different shades of pink. From perfectly transparent stones to material with visible milky inclusions, these unusual stones indicate that a wonderful journey yet awaits us.

Figure 4. Rainbow over Montana bracelet. Yellow gold and sapphires from Montana. Photo courtesy of Paula Crevoshay.
Illuminations, from Earth to Jewel runs at the Museum of Mineralogy at the ParisTech School of Mines until Wednesday, February 1, 2017. General admission is 6€. Students and seniors are 3€, and children under 12 are free. The museum is open Tuesday through Friday from 1:30 to 6:00 pm and Saturday from 10:00 am to 12:30pm and 2 to 5pm; it is closed on Sunday and Monday. @chapter:21


Publication Year: 1989 Title: Blue Pectolite from the Dominican Republic Abstract: Blue pectolite from the Dominican Republic, also known by the trade name Larimar, has recently entered the U.S. market. Large quantities of this attractive ornamental stone have been found in cavities and veins of altered basalt. Most of the gemological properties are consistent with those previously reported for pectolite; the cause of color in this material is believed to be related to the presence of small amounts of Cu2+. The color appears to be stable to light, but does react to irradiation and to the heat of a jeweler's torch. It is easily separated from similar-appearing materials. @chapter:4


Publication Year: 2015 Title: 2015 Sinkankas Symposium Abstract: This Mexican opal in rhyolite is from the Iris mine, Hacienda Esperanza, in Querétaro. The Mineralogical and Geological Museum at Harvard University, received this specimen as a donation from James Garland in 1892, facilitated by George Frederick Kunz. It measures 7 × 6 cm and is the finest opal in the museum’s collection. Photo by Robert Weldon/GIA, courtesy of the Mineralogical and Geological Museum, Harvard University.

The thirteenth annual Sinkankas Symposium was held April 18 at GIA headquarters in Carlsbad, California. Co-hosted by the Gemological Society of San Diego, GIA, and Pala International, the event drew a capacity crowd eager to learn about opal.

After welcoming remarks from organizer Roger Merk, the morning presentations began with an overview by Dr. Eloïse Gaillou (Paris School of Mines) on geology, color, and microstructure. Andrew Cody (Cody Opal, Melbourne) chronicled the Australian opal market before delving into fossilized specimens. Dr. Raquel Alonso-Perez (Mineralogical and Geological Museum, Harvard University, Cambridge, Massachusetts) spoke on the history of the museum and shared photos and data of specimens from its collection. Photographer Jack Hobart showed superb images from his extensive database of Mexican opals. Bill Larson (Pala International, Fallbrook, California) described his personal collection of Mexican, Australian, Ethiopian, and Brazilian opals, many of which were on display throughout the campus.

The afternoon sessions began with a presentation by Alan Hart (Natural History Museum, London) on the museum’s opal collection. Noted lapidary Meg Berry (Megagem, Fallbrook, California) described various techniques for cutting and carving. Buying guide author Renée Newman (International Jewelry Publications, Los Angeles) discussed the jewelry uses of matrix and common opal. Helen Serras-Herman (Gem Art Center, Rio Rico, Arizona) followed with additional insight on the many varieties of common opal. Robert Weldon (GIA, Carlsbad) discussed the challenges of photographing opal’s shifting flashes of color, as well as the instruments and post-production techniques best suited to the task. Nathan Renfro (GIA, Carlsbad) looked at the gem’s internal features and the wide range of mineral inclusions that create vibrant, colorful scenes. Dr. George Rossman (Caltech, Pasadena, California) examined causes of color and offered closing remarks.

Sapphire will be the theme of the 2016 symposium. For more information on the event or to purchase the proceedings volume, visit www.sinkankassymposium.net. @chapter:39


Publication Year: - Title: RJC Panel Explores Colored Gemstone Issues at Baselworld 2017 Abstract: The Responsible Jewellery Council panel on colored gems discussed sustainability issues at the March Baselworld trade fair. From left are Thomas Hainschwang, Eleonora Rizzuto, Jack Cunningham and Jean-Claude Michelou. Anne Marie Fleury, far right, moderated the panel. Photo by Russell Shor/GIA

	The colored gemstone industry is moving toward sustainable mining practices, but a wide array of issues remain before the Responsible Jewellery Council (RJC) can add more miners and suppliers of colored gemstones to its membership roster.

	The London-based RJC is an independent standards-setting organization that promulgates sustainable labor, environmental and trading practices within the gem and jewelry industry.

	The council held a panel discussion on the challenges and issues of certifying colored gem firms on March 23 at the Baselworld fair in Switzerland, one year after it decided to study how it could expand its membership into this sector of the trade.

	As detailed in a 2016 Gems & Gemology article, “ The Color of Responsibility: Ethical Issues and Solutions in Colored Gemstones,” the colored stone industry is extremely fragmented with dozens of different types of gemstones mostly mined by small operators or artisanal diggers in 47 countries spread across six continents.

	The RJC panelists, led by Anne Marie Fleury, director of standards and impacts for the Council, included Eleonora Rizzuto, Bulgari’s director of sustainability and corporate responsibility; Jack Cunningham, Gemfields’ manager of sustainability projects; Thomas Hainschwang, a partner in GGTL Laboratories in Liechtenstein; and Jean-Claude Michelou, who leads the International Colored Stone Association’s sustainability efforts.

	The panelists agreed that the first task is to determine which colored stones to include under RJC’s aegis. Ruby, sapphire and emerald would be covered at a minimum, though Michelou said that eventually all commercially produced gemstones should be included.

	Second, they agreed that establishing a common standard for producers to follow is difficult because each country has different laws and regulations.

	Rizzuto said Bulgari has been visiting the mines its suppliers source their gemstones from to evaluate conditions there.

	“Our review programs include all stakeholders, from financial, mine workers and dealers, all the way through the supply chain,” she said.

	Cunningham added that Gemfields, among others, assures the chain of custody all the way through the polishing process and hosts major buyers and sustainability experts at its mining sites in Mozambique and Zambia.

	There’s a consensus that consumers are increasingly aware of responsibly produced gemstones, but, Cunningham noted, “it’s early days” to assume that demand would be sufficient to market them as a separate category.

Most colored gemstone mining operations are small, fragmented and lightly mechanized, such as this sapphire operation in Thailand. Visiting and monitoring such mines is a challenge for Responsible Jewellery Council certification. Photo by Russell Shor/GIA.

	Along with sustainable mining, ongoing research to identify gemstones by their country of origin is needed.

	Hainschwang reported that this research remains difficult because some gems from different sources may have very similar characteristics and some gemological labs often list different origins for the same stone when they are resubmitted for testing.

	In addition, treatments can obscure some of the characteristics that help identify origin.

	GIA has been conducting a long-term, extensive research program of collecting gemstones from all known sources to build a database from which origin can be reliably determined.

	Later in the discussion, Linda Cromwell, of the London Bullion Market Association, stressed the need to diligently review and monitor members’ activities for the Council to keep its credibility.

	RJC Managing Director Andy Bone said the council has a thousand members and continues to grow because the alternative will be more governments adding scrutiny and regulation to gem and jewelry trading. @chapter:38


Publication Year: 2021 Title: Transparent Rhodonite with Clarity Enhancement Abstract: Figure 1. A large 11.32 ct rhodonite showing vivid orangy red color and visible needle-like inclusions. Photo by Diego Sanchez.

Recently the Carlsbad laboratory received a transparent vivid orangy red rhodonite for identification service (figure 1). Standard gemological testing revealed a double refractive index of 1.727–1.738, and a specific gravity of 3.66 was obtained. The stone was inert to both long-wave and short-wave UV light. These properties were consistent with rhodonite (R. Webster, Gems, 5th ed., rev. by P.G. Read, Butterworth-Heinemann, Oxford, 1994, p. 365). Rhodonite, with the formula CaMn3Mn[Si5O15] (mindat.org), is a member of the triclinic crystal system and occurs in manganese-bearing rocks.

Figure 2. These scattered randomly oriented curved needle-like inclusions are likely the mineral cummingtonite. Photomicrograph by Nathan Renfro; field of view 2.56 mm.

Figure 3. Low-relief fractures with high-relief trapped gas bubbles offer proof of clarity enhancement in the faceted transparent rhodonite. Photomicrograph by Nathan Renfro; field of view 3.12 mm.
During microscopic analysis, scattered curved needle-like inclusions (figure 2) were observed as well as fractures with clarity-enhancing residue that also contained high-relief areas where gas bubbles were trapped (figure 3). Although the source of this particular rhodonite is unknown, curved needle inclusions in transparent rhodonite from Brazil were previously reported in 2004 and 2008 (Fall 2004 GNI, pp. 260–261). The appearance of the needle-like inclusions was consistent with those previously identified as cummingtonite (P. Leverett et al., “Ca-Mg-Fe-rich rhodonite from the Morro da Mina mine, Conselheiro Lafaiete, Minas Gerais, Brazil,” The Mineralogical Record, 2008, Vol. 39, pp. 125–130).
In addition to Brazil, Australia is a well-documented source of gem-quality rhodonite (P. Millsteed et al., “Inclusions in transparent gem rhodonite from Broken Hill, New South Wales, Australia,” Fall 2005 G&G, pp. 246–254). Despite being clarity enhanced, this saturated gem-quality rhodonite was exceptional for its bright vivid color, transparency, and size. @chapter:13


Publication Year: 1985 Title: Altering the Color of Topaz Abstract: The various techniques in use today to alter colorless topaz to produce brown, pink, and most commonly, blue stones are discussed. Special attention is given to the three irradiation sources -gamma rays, high-energy electrons, and neutrons - used to convert the colorless stones to hues in the yellow to brown range and the subsequent heat treatment required in most cases to turn the irradiated stones blue. The blue color produced by irradiation and subsequent heat treatment is stable to light. Currently, no routine gemological tests are available that can definitively determine whether the color of the topaz is natural or the result of treatment. @chapter:2


Publication Year: 2010 Title: Color Alterations in CVD Synthetic Diamond with Heat and UV Exposure: Implications for Color Grading and Identification Abstract: In response to heat and UV exposure, some synthetic diamond gemstones grown by chemical vapor deposition exhibit large, reversible changes in color. A significant reduction in color was achieved by heating several CVD synthetic gemstones to 450°C. Conversely, a darker color was observed in samples following exposure to UV radiation (such as that used in gem testing). Both the heated and UV-exposed samples returned to their initial (stable) color when they were illuminated for >30 minutes with a standard daylight-equivalent lamp used for grading. However, these color states did not change with time when the samples were kept in the dark. Heating and UV exposure also influenced the strengths of various IR absorption features that might be used to identify such a sample as a CVD synthetic. These nonpermanent changes might affect the apparent color grade of a CVD synthetic diamond, and care must be employed in the interpretation of spectroscopic features used to determine a stone’s natural or synthetic origin. @chapter:11


Publication Year: - Title: Bench Tip #9: Use the Touchstone Method for Testing Purity in Karat Gold Abstract: Touchstone method

There are a few scientific methods for precisely determining karat gold purity, some destructive (fire assay) and others nondestructive (X-ray fluorescence). Both methods require costly equipment, special procedures and a well-lit and ventilated area. A simpler method for determining gold purity in jewelry is the “touchstone” testing process, an age-old technique that is relatively nondestructive to jewelry and offers quick results.

Use with care: Touchstone testing incorporates the use of acids, so pay close attention to safety.  Careful procedures are a must.

Touchstone testing is based on the fact that 24k gold resists all but the strongest acids. The purer the gold, the stronger the acid required to dissolve it. Measured strengths of nitric acid are used to test for 14k and lower. Aqua regia, a mixture of one part nitric acid and three parts hydrochloric acid, is used to test higher karat purity through the process of comparison and elimination.

To conduct touchstone testing, you’ll need an acid testing kit (available through jewelry tool suppliers), a well-ventilated area, two glass beakers, water, baking soda, protective gloves, 320-grit abrasive paper, safety goggles, and paper towels.

Your testing kit includes a set of testing needles. Each needle has a karat gold sample on its tip and the karat value stamped on the side. Use yellow gold needles for testing yellow gold, and white gold needles for testing white gold.

	Each known test sample is labeled on the needle. Rub the known samples onto the stone and label each on the testing stone.
Begin by checking the gold jewelry piece for other stampings (e.g., quality marks or manufacturer’s marks) and make note of characteristics such as heft, color and reflectivity. If you suspect the item may not be gold, use an engraving tool and make a small notch in an unobtrusive place on the jewelry to expose fresh metal. Next, put on protective gloves and place a drop of acid from the 18k gold testing bottle over the small notch. A highly effervescent green reaction indicates base metal, and no further testing is required.

If there is little or no reaction, the piece is likely karat gold, and the next test is for purity. Follow these steps:
• Rub the jewelry of unknown karat purity gently back and forth on the testing stone to leave a thin, but clearly visible, metal sample. Use care to take this sample from a place not clearly visible on the jewelry and away from solder joints.
• With a testing needle, draw a question mark on the touchstone that represents the unknown metal.
• Start with the 14k testing needle and rub a layer next to the unknown. Label it “14.”
• Repeat this process, making a layer and then labeling with the 18k, 22k, and 10k testing needles. Now choose the bottle labeled for testing 10k and lightly swipe the applicator across all the samples.
• After approximately 20 to 40 seconds, place the touchstone in a mixture of baking soda and water to neutralize the acid in one beaker, then rinse in water in the other beaker.
• Blot the touchstone with paper towels and observe. The 10k sample has dissolved, but the unknown metal is still visible. This confirms the unknown metal is finer than 10k.
• Next, choose the bottle labeled for testing 14k and swipe it across the samples just below the first test.
• Allow enough time for the acid to react and neutralize, then rinse and blot the touchstone and observe. The acid has dissolved both the 10k and 14k samples. The unknown metal is therefore 14-karat or slightly higher.

	Analyze the test results to determine the karatage.
Always prepare the touchstone for its next use by cleaning it thoroughly. Remove the metal from the stone’s surface by placing it facedown on a piece of 320-grit abrasive paper on a flat surface. Apply moderate pressure and sand it in a circular motion until sample layers are no longer visible. Neutralize, rinse and blot dry before replacing in the kit. Always follow the manufacturer’s directions for the proper care, storage and handling of acids @chapter:24


Publication Year: - Title: Books: Cycles of Life: Rings from the Benjamin Zucker Family Collection Abstract: By Sandra Hindman, with Beatriz Chadour-Sampson, Reine Hadjadj, Jack Ogden, and Diana Scarisbrick, hardcover, illus., 258 pp., publ. by Paul Holberton Publishing, London, 2014, £35.00.

Cycles of Life: Rings from the Benjamin Zucker Family Collection celebrates 40 years of collecting by one of the world’s most notable gem dealers. The book is the third in Hindman’s series on recent exhibitions at Les Enluminures, her gallery specializing in manuscripts, miniatures, and jewelry from the Middle Ages and the Renaissance.

	Hindman presents a selection of rings from the Zucker collection, much of which has been on loan to the Walters Art Museum in Baltimore since 1985. They are organized according to the talismanic, symbolic and commemorative roles rings have played in birth, marriage, death, and everyday life, and even as a symbol of eternity.

	Although organized by life cycles, the rings also document the changes in styles through the ages. Hindman describes the forces that were often behind these changes, such as the discovery of Brazilian diamonds, which caused the proliferation of diamonds in rings; and the  wars, disease, and plagues of the 1600s that led to the commemorative “memento mori” rings. It is also intriguing to see the continuity of jewelry design. Many of the pieces would not be out of place in a modern jewelry store: diamond solitaires, with the stones set high and with open sides so that light can enter; clusters of small diamonds that give the impression of greater size; and trios of diamonds set on the shoulders of rings.

	Hindman opens each section with an appropriate illustration from a medieval or Renaissance manuscript. Other reproductions of paintings and illuminations show how rings were actually worn in the past. My favorite illustration is from the beginning of the “Everyday Life” chapter. It shows a busy jewelry shop in the Middle Ages, with cloths spread with gems on the counters, and jewelry and vessels displayed on the shelves in the back. Change the clothing and it could be almost any family-run jewelry store today.

	As Hindman notes early on, rings often fit into multiple categories, and Cycles of Life is not meant to force them into rigid classifications. Instead, the book considers how, since the dawn of history, rings have encapsulated our hopes, our desires, our fears.

	“Birth” includes rings that offer prayers to Mary and Christ—both virgin births. A spectacular “gimmel”—or twin—ring, with its engraved and enameled interlocking shanks, opens to show a figure of a baby on one side and a skeleton on the other. It serves as a reminder of the importance of humility, signaling that the end of life is death, and that all things pass.

	“Marriage” features a broad selection of elaborate Jewish marriage rings—probably only worn during the wedding ceremony. Fascinating “key” rings indicate that, upon marriage, wives took on the keys to the stores and the responsibility of feeding the household. Most of the rings have been decorated with loving sentiments. Hindman traces the shift from the medieval practice of engraving sentiments on the outside of the ring shanks, in a public display, to the Renaissance practice of engraving them privately inside the rings.

	“Everyday Life” illustrates seal rings used for signing documents, rings engraved with crests and coats of arms identifying families, and gemstone rings worn not necessarily for vanity, but to invoke the special power and properties often associated with those stones.

	Medieval rings in the “Death” section show the well-warranted fears of mortality in that era. They are inscribed with charms and prayers, and set with stones believed to have magical properties. “Death jewelry,” writes Hindman, “appeared to have enjoyed a vogue” in the late Renaissance. These rings, worn in remembrance of a lost loved one, might today be considered gruesome: decorated with skulls and bones, or containing the hair of a deceased person. Such rings were often set with diamonds, a symbol of eternal life.

	Finally, “Eternity” tracks the evolution of the diamond ring from ancient Rome to the modern era. As Hindman writes, this section presents “a kind of mini-history of the diamond ring,” following the history of setting and cutting. Known since antiquity for their indestructibility, diamonds quite naturally became a symbol of eternity—hence their eventual use in betrothal and wedding rings. Diamonds represented the enduring nature of a monarch’s reign and, perhaps not inconsequentially, were believed to protect against poisoning. As already mentioned, diamonds in memento mori rings signified the eternal nature of the soul. The inclusion of perpetual calendar rings seems a bit out of place among so many diamonds, but is appropriate to rings dealing with eternity. This section acknowledges Benjamin Zucker’s long love affair with diamonds and diamond jewelry, and the important place they hold in his collection.

Cycles of Life is primarily a catalog of an exhibition of the same name at Hindman’s Les Enluminures gallery in New York that ran from Oct. 30 to Dec. 6, 2014. Excellent notes on provenance and sources as well as comparable pieces make this a valuable resource for the specialist. It also makes absorbing reading for non-specialists with an interest in jewelry history; the notes and bibliography provide gateways to further study. Comparison pieces show how styles influenced and were influenced by others. Descriptions of shank shape, enameling and setting techniques, manufacturing methods, and metal types offer fascinating windows into the superb skills of jewelers through the ages. Notes on gemstones serve as a reminder of the extent of trade in the ancient world: Garnets from India and emeralds from Egypt appear in ancient Roman rings.

	In addition to the breadth of the collection, the quality of the pieces is astonishing. Many are in excellent shape, with gemstones and even enameling in place. Excellent photos taken from multiple angles allow the reader to examine minute details of each ring, from enameling and engraving to areas of damage and repair.

	In addition to the five sections—Birth, Marriage, Everyday Life, Death, and Eternity—the book includes a preface by Benjamin Zucker outlining his initiation into the world of ancient jewelry as a young man just out of Harvard, through his lifelong habit of collecting. There is also a bibliography of Zucker’s writing, and a separate bibliography of references.

Cycles of Life would make a worthwhile addition to the library of anyone interested in jewelry history. @chapter:21


Publication Year: - Title: Heart Jewelry and Gems for a Valentine Abstract: This heart-shaped 8.01ct Burmese ruby ring, set in platinum and surrounded with diamonds evokes love and passion just in time for Valentine’s Day. Photo by Robert Weldon/GIA, courtesy of Jan Goodman Co.

	The heart has been celebrated as the dwelling place of romantic love for centuries. Some scholars speculate that the earlier winged Cupids with heart-shaped arrows depicted in Renaissance art symbolized love, while others say the heart as the seat of affection dates back the first century BCE.

	Hearts and Valentine’s Day were forever wedded when Hallmark began mass production of Valentine’s Day cards in 1913. Today, it’s a holiday celebrated around the world.

	Valentine’s Day has a long tradition. In 496 CE Pope Galasius designated February 14th as a feast day to mark the martyrdom of Saint Valentine. While little is known about him, he is considered the Patron Saint of love, blissful engaged couples and happily married people. His image is often associated with birds and roses.

View Gallery

		To-morrow is Saint Valentine’s day,
		All in the morning betime,
		And I a maid at your window,
		To be your Valentine.
Hamlet, Shakespeare

	You don’t need to be in love to appreciate the romance and devotion of Valentine’s Day, or the beauty of the heart-shaped gems and heart-inspired jewelry. If you “heart” jewelry and gems, every day is Valentine’s Day. @chapter:16


Publication Year: 2013 Title: Gem Olivine and Calcite Mineralization Precipitated from Subduction-Derived Fluids in the Kohistan Arc-Mantle (Pakistan) Abstract: Geochemical data in this study suggests that remobilized CO2 and H2O from a subducted island arc helped form the calcite + olivine-bearing veins in Kohsitan, Pakistan. The authors provide details on the geologic setting, mineralogy, and geochemistry of the vein assemblages, which can yield gem-quality olivine (peridot). The CO2 and H2O from island arc magmas and carbonates mixed with mantle fluids rich in Bo (as evidenced by ludwigite-vonsenite needlelike inclusions in olivine) as well as La, Ce, Ta, Cu, and Zn (from trace-element analysis). Fluid origin and emplacement are discussed at length, with emphasis on macro-geophysical mechanisms within the earth. Gem olivine production data and characterization of the rough were not provided.

Abstracted by Keith A. Mychaluk @chapter:0