Publication Year: - Title: Winter 2011 G&G Lab Notes Abstract: A Rare Fancy Vivid Purple Diamond
	A Strongly Purple-Colored Black Diamond
	HPHT-Treated Diamond with Fluorescence Pattern of an HPHT-Grown Synthetic
	Type IIb Diamond with Long Phosphorescence
	Clarity-Enhanced Opal with Artificial Matrix
	Ethiopian Black Opal
	Coated Bead-Cultured Freshwater Pearls
	Tenebrescent Zircon

To view the full section, download the PDF above.

	DATA DEPOSITORY

	Type IIb Diamond with Long Phosphorescence - Videos (see below)
	January 18, 2012

	Type IIb DiamondPhosphorescence

	Type IIb DiamondPhosphorescence & Thermoluminescence @chapter:11


Publication Year: 2022 Title: Breyite Inclusion in Diamond Abstract: A breyite inclusion in diffuse illumination. Doubling of some features to the right and left of the inclusion is an artifact of viewing through multiple pavilion facets. Photomicrograph by Evan M. Smith; field of view 1.58 mm.
Sublithospheric or “superdeep” diamonds are rare, estimated to make up only 1–3% of mined diamonds globally. They are recognized on the basis of their mineral inclusions. Breyite (CaSiO3) is one of the minerals sometimes encountered in this curious geological family of diamonds. Diamonds containing breyite are often interpreted to come from depths greater than 360 km, where the breyite would have initially had a high-pressure perovskite-type crystal structure. The perovskite-structured CaSiO3 would have changed to the breyite crystal structure in response to the drastic decrease in pressure during the diamond’s journey to the surface. Alternatively, it is theoretically possible that breyite could be trapped directly in a diamond at much shallower depths, say within 150–200 km, although such an occurrence within a known lithospheric diamond has yet to be encountered.
The breyite inclusion (see above) was recently observed in a 1.00 ct D-color type IIa diamond submitted to GIA’s New York laboratory. Raman spectroscopy was used to identify it as breyite. This large inclusion, 450 μm in its longest dimension, is colorless and transparent. A conspicuous healed fracture surrounds it, containing graphite (black) and smaller “sub-inclusions” of breyite that appear to emanate from the main inclusion. Based on this breyite inclusion, the diamond is suspected to be sublithospheric in origin @chapter:35


Publication Year: - Title: How to Choose a Gem of a Jeweler Abstract: Purchasing a piece of jewelry requires important decisions. Just as you consult with other professionals for important advice, such as a family doctor or lawyer, you should turn to a professional jeweler to make a jewelry purchase a pleasurable event.

Here are some guidelines for selecting a professional jewelry.

First, a professional jeweler should have the knowledge and training to help you make an informed purchase. Look for credentials that indicate professional experience. For example, the initials GG (Graduate Gemologist) after a jeweler’s name indicate that the jeweler has had a high level of gemological training. A GG should be up to date on the industry’s most relevant developments through GIA’s continuing education programs such as the Continuing Education Recognition Program.

In addition to product knowledge, a jeweler’s reputation is one of his or her most valuable assets. Ask friends for recommendations, or ask a jeweler to provide references. Find out how long the jeweler has been in business, check for affiliations with industry associations and ask whether he or she is an active member of the GIA Alumni Association.

If you are buying a diamond or colored gemstone, consider getting a report from an independent laboratory with your purchase. For example, professional jewelers worldwide provide independent diamond grading reports with their fine diamonds. The most widely used and respected are those issued by the GIA Laboratory, which created the diamond grading system. A jeweler can even arrange to have a diamond’s unique GIA Diamond Grading Report number, or even a personal message, laser inscribed onto its girdle (outside edge) for easy identification.

Be sure to ask jewelers about the types of services they provide – such as repairs, appraisals, and inscriptions – the range of products offered and the store’s return policy and credit terms. @chapter:28


Publication Year: - Title: GIA Field Gemologists Seek Blue Sapphire and Lapis Lazuli in Mogok, Myanmar Abstract: Hunting Sapphire and Lapis in Mogok

	GIA field gemologists seek Mogok’s blue sapphire and lapis lazuli.

	In this short video, you’ll witness the fascinating work of GIA’s dedicated Field Gemologists Vincent Pardieu and Andy Lucas as they seek sapphire and lapis lazuli for the institute’s reference collection. With them, you’ll follow Mogok’s miners deep underground. As Pardieu explains, “…to see the work they’re doing in order to bring the gems out of the ground …I’m amazed all the time.”

	The Mogok valley is unique—no other gem deposit in the world has ever produced such a variety and quantity of exceptional gems over such a long period of time. As Pardieu explains, “Stones are durable, so all the stones that were mined in Mogok over the last thousand years …they are still here…in the market somewhere…maybe in New York, in Paris, in London, in Tokyo…in China. People own them.”

	Discovered centuries ago, Mogok remains one of the most active gem deposits in the world, and also one of the most secretive. During most of its history it was not accessible to foreigners. Indeed, the area only opened up to gemologists in June of 2013.

	In the video, GIA takes you to the Mogok valley. The mining area is about 400 miles (650 km) north of Yangon in a densely vegetated, mountainous area rising to 7,700 feet (2,347 meters) above sea level. With an unparalleled reputation as the source of fine gemstones going back more than 800 years, Mogok is known to produce rubies, sapphires, spinel, peridot and many other gems.

	You’ll see all these gem types at Mogok’s bustling markets. There, the GIA gemologists find what’s claimed to be locally mined lapis lazuli. “It would be interesting to find it,” says Pardieu. “In several books and articles, there is a report about lapis deposits in Burma, but this is not confirmed.”

	In this video, you’ll follow them in their search for the lapis mine as they locate the spot and collect samples for the GIA reference collection.

	These GIA Field Expeditions (FE49 and FE50) took place in January 2014. Gemologists Vincent Pardieu and Andy Lucas were accompanied by cameraman Didier Gruel. @chapter:25


Publication Year: - Title: Fall 2009 Gem News International Abstract: Diamonds
	            A Greenish Yellow Diamond with Glass Filling and HPHT Treatment
Colored Stones and Organic Materials
	            Aquamarine with Ocean-Themed Inclusions
	            “Smoky” Gray Beryl
	            Chalcedony from Oregon with Pyrite and Cloud-Like Green Areas
	            Demantoid from Ambanja, Madagascar
	            Enstatite from Pakistan
	            Common Opal from Argentina
	            Mabe Pearls from Vietnam with Seashell Nuclei
	            Characterization of Some Pearls of the Pinnidae Family
	            Cat’s-Eye Phenakite
	            Color-Change Pyrope-Spessartine from Kenya
	            Preliminary Observations on New Rubies from Mozambique
	            Yogo Sapphire Update
	            Topaz with Unstable Brown Color
	            New Tourmaline Production from Keffi, Nigeria
	            “Lilac”-Colored Cu-Bearing Tourmaline from Nigeria
	            Triphylite from Brazil
Synthetics and Simulants
	            Colorless Synthetic Sapphire Imitating Rough Diamond
Miscellaneous
	            Update on Myanmar Gems
Conference Reports
	            3rd European Gemmological Symposium
Announcements
	            CIBJO Resources for Retailers
	            Gem Cutting Notes Available

To view the full section, download the PDF above.

	DATA DEPOSITORY

Demantoid from Ambanja, Madagascar - Additional Photos
Enstatite from Pakistan - Photomicrographs and Absorption Spectra
New Tourmaline Production from Keffi, Nigeria - Average Chemical Composition of Tourmaline by Electron Microprobe
Colorless Petalite and Pollucite from Laghman, Afghanistan - Faceting Notes
	Fall, 2009 @chapter:3


Publication Year: 2015 Title: Large Namibian Demantoid Garnet Abstract: Figure 1. This selection of andradite garnet from Namibia’s Green Dragon mine includes an 11.63 ct demantoid round brilliant, an unusually large stone for this source. Photo by Robert Weldon/GIA, courtesy of Green Dragon mine.

              At the GJX show, Stefan Reif (Tsuen Wan, N.T., Hong Kong), showed us an 11.63 ct round brilliant demantoid garnet. It was an exceptional stone of intense vibrant green with a touch of blue. According to Reif, the original rough weighed approximately 46 ct—about 9 grams—making the yield a little over 25%. This is an exceptionally large gem for Namibia’s Green Dragon mine, where the bulk of production is suitable for small calibrated gems.

Namibian demantoid was first discovered in the 1990s (Fall 1997 GNI, pp. 222–223). The current production came from an open-pit, hard rock mine with an annual production between 5,000 and 10,000 carats. According to Reif, the local geology includes marble, pegmatite, and rhyolite. The distribution of demantoid pockets within these rocks is irregular and difficult to predict. Beside the geological challenges, water is scarce, and temperature extremes range from freezing at night to baking desert heat in the daytime.

The Green Dragon mine is renowned for its production of well-proportioned rough. This material is suitable for cutting smaller gems into 2–3 mm sizes in a range of colors from slightly bluish green through “lemongrass” green to greenish yellows and reddish browns. These are used for precision-cut calibrated and melee-sized goods placed as accent stones in high-end jewelry. Most of the cutting is done in Thailand, and the yield is approximately 10% due to the desire for well-proportioned cut gems. Besides precision-cut demantoid and andradite garnet in calibrated sizes, Reif also cuts to higher tolerances for the watch industry, producing 3 × 2 mm tapered baguettes for watch bezels.

Even in these small sizes, well-cut gems display high luster and very distinct fire, making them an excellent visual alternative to diamond. Rough suitable for gems of 6.0 mm (about 1 ct) is much rarer, but material for larger gems does come up once in a while. @chapter:3


Publication Year: 2016 Title: Dolomite with Unusual Inclusions Abstract: These brownish orange cubic to rhomb-shaped inclusions were identified by Raman analysis as svanbergite in dolomite. Photomicrograph by Jonathan Muyal; field of view 14.52 mm.

	Dolomite is not often encountered as a gem material, and it is generally known as an inclusion in gems such as emerald, garnet, quartz, and ruby. In view of this, any inclusions found within gem-quality dolomite may be justifiably considered as rare inclusion/host combinations.

	One particular area known to produce gemmy dolomite suitable for lapidary work is the Mount Brussilof mine in Radium Hot Springs, British Columbia, Canada. Also found at this mine in direct association with the dolomite are crystals of the relatively rare mineral svanbergite.

	Crystallizing in the trigonal crystal system in a rhombohedral to pseudocubic habit, svanbergite is not a widely known mineral associate of dolomite or any of the other common carbonates. It is a member of the beudantite mineral group and is composed of basic phosphate and sulfate of strontium and aluminum phosphates and sulfates. Svanbergite colors range from reddish brown to orange; there is also colorless material.

	Recently we had the opportunity to examine a cluster of inclusions surrounded by numerous tiny fluid inclusions within a colorless gem-quality dolomite. It came as a delightful surprise when laser Raman microspectrometry revealed these crystals to be svanbergite, an inclusion-to-host pairing we’ve never previously encountered. @chapter:13


Publication Year: - Title: GIA's Gubelin Gem Project: Corundum Abstract: Corundums (ruby and sapphires) occur in all colors of the spectrum, and have remained popular gemstones from ancient times to the present day. Photo by Robert Weldon/GIA

Ruby and sapphire (usually blue, but also in every other color) have been the most important colored gemstones for several thousand years. Originating historically in southeast and central Asia, and more recently in eastern Africa, these colored varieties of the mineral corundum have been much sought as gems because of their rarity, color and durability. Gem corundum can display asterism and chatoyancy due to the presence of oriented mineral inclusions, and in some cases, a change of color when viewed under different light sources.

33066

1.77 ct Corundum - Ruby  Myanmar (PDF)

33068

1.62 ct Corundum - Ruby  Nepal (PDF)

33069

2.02 ct Corundum - Ruby  Sri Lanka (PDF)

33070

3.05 ct Corundum - Ruby  Sri Lanka (PDF)

35115

 2.47 ct Corundum - Ruby  Thailand (PDF)

35103

1.92 ct Corundum - Sapphire Cambodia (PDF)

34572

2.97 ct Corundum - Sapphire  Myanmar (PDF)

33081

3.46 ct Corundum - Sapphire  Myanmar (PDF)

33085

4.38 ct Corundum - Sapphire  Myanmar (PDF)

34575

5.78 ct Corundum - Sapphire  Myanmar (PDF)

33078

6.40 ct Corundum - Sapphire  Myanmar (PDF)

35147

3.89 Corundum - Sapphire  Thailand (PDF)

35146

3.97 ct Corundum - Sapphire  Thailand (PDF)

34581

6.99 ct Corundum - Sapphire  Myanmar (PDF)

34580

8.29 ct Corundum - Sapphire  Myanmar (PDF)

33092

3.48 ct Corundum - Sapphire  Sri Lanka (PDF)

33074

4.51 ct Corundum - Sapphire  Sri Lanka (PDF)

33075

6.36 ct Corundum - Sapphire  Sri Lanka (PDF)

33061

7.74 ct Corundum - Sapphire  Sri Lanka (PDF)

33063

8.70 ct Corundum - Sapphire  Sri Lanka (PDF)

33079

9.16 ct Corundum - Sapphire  Sri Lanka (PDF)

35144

4.94 ct Corundum - Sapphire  Thailand (PDF)

35128

5.28 ct Corundum - Sapphire  Thailand (PDF)

33084

15.87 ct Corundum - Sapphire  Sri Lanka (PDF)

33087

4.29 ct Corundum - Sapphire  Tanzania (PDF)

33077

 5.06 ct Corundum - Sapphire  Tanzania (PDF)

35138

2.20 ct Corundum - Sapphire  Thailand (PDF)

35095

2.72 ct Corundum - Sapphire  Thailand (PDF)

35111

 2.72 ct Corundum - Sapphire  Thailand (PDF)

33080

2.86 ct Corundum - Sapphire  Thailand (PDF)

35112

3.01 ct Corundum - Sapphire  Thailand (PDF)

35113

3.39 ct Corundum - Sapphire  Thailand (PDF)

35110

3.76 ct Corundum - Sapphire  Thailand (PDF)

33091

7.65 ct Corundum - Sapphire  Thailand (PDF) @chapter:3


Publication Year: 1982 Title: Fall 1982 G&G Lab Notes Abstract: Chalcedony, Repaired Cameo
Diamond Fake Crystal
Rare Inclusion in Diamond
Manufactured Emerald Specimens
Iolite, an Unusual Cat's-Eye
Jade Imitation
Lapis Lazuli Imitation
Pink Opal, a Rare Bird Indeed
Conch "Pearl"
Sapphire, Diffusion Colored
Spinel?

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


Publication Year: 2012 Title: Sapphires from Thammannawa, Kataragama Area, Sri Lanka Abstract: The February 2012 discovery of high-quality blue sapphires at Thammannawa near Kataragama in southeastern Sri Lanka has intensified gem mining and exploration in the surrounding area and all over the country. The deposit is hosted by the Kataragama klippe, and corundum mineralization is associated with pegmatitic intrusions and surrounding micaceous layers. Well-formed crystals from this primary deposit display flat faces and sharp edges with an unusually vitreous luster. The sapphires possess good transparency and a pure blue color that is characteristic of corundum from this deposit. Several kilograms of rough material have been produced so far, with some crystals larger than 200 g. Faceted blue sapphires of fine color and weighing more than 20 ct have been cut. @chapter:4


Publication Year: 2023 Title: Liberian Ruby Abstract: Figure 1. A handful of gem gravel collected from the Lofa River in Weasua, Liberia, showing the high concentration of ruby material. Photo courtesy of Diamonds for Peace.
A gemological education can often prove useful in the most unusual of circumstances. On a recent trip to rural Liberia with the Japan-based NGO Diamonds for Peace (DfP), the author discovered a previously unacknowledged source of ruby. The original purpose of the visit was to deliver a rough diamond grading and valuation workshop to the miners working and living in 17 communities across Liberia. During the trip, the author stayed in the town of Weasua, one of the larger mining communities, to experience the standard of living and the general working conditions of the miners. The poverty is extreme. Most homes are without electricity, facilities, or running water, and only three functional water pumps exist for a population of 5,000, all of which place the health and the well-being of this community at risk. DfP has been working with this community since 2018 and has made significant inroads in supporting and improving the lives of these miners, but there is a long way to go, and strategies to aid their mission are continually being developed.

Figure 2. Left: One of the Liberian diamond miners displays some of the rubies she found while digging. Right: A ring mounted with a Liberian ruby. Photos by Diamonds for Peace (left) and Alex Herbert (right).
It was therefore fortuitous that during the visit, the author learned that there were other promising gem-quality minerals in the alluvial gravels the miners were collecting in their pursuit of diamond (figure 1). Upon initial inspection while on-site, the author noted material resembling corundum (primarily ruby), garnet, topaz, rock crystal quartz, and possible spinel. Samples were purchased from the miners for analysis, which came as a welcome surprise since they were unaware that these colored stones could carry any value (figure 2, left).
The author subsequently analyzed all the samples at the Gemmological Certification Services (GCS) laboratory in London. Using advanced and standard gemological testing, the identity of all the presumed gem-quality minerals of the collected specimens was confirmed. Particular focus was placed on the rubies due to their apparent abundance at the mine site, with the hope of providing another means of income for this community.
All ten samples tested were identified as corundum. Due to the nature of the rough material, standard testing was limited, beyond measuring specific gravity—which, averaging 4.0 across all samples, supported corundum. The ultraviolet/visible/infrared absorption spectrum, with its chromium-associated features, was also consistent with ruby. X-ray fluorescence analysis of the trace element chemistry revealed 1029–2377 ppm iron and 721–2915 ppm chromium, with low levels of gallium (54 ppm) and vanadium (53 ppm).
Generally, the color of the alluvial material collected ranged from pinkish gray to a deep purplish red, with sizes varying from 6 to 14 mm (1.45–15.90 ct), although the author was shown larger pieces on-site. All of the material showed a moderate to weak red fluorescence response in long-wave UV and inert to weak red in short-wave UV, consistent with high-iron ruby due to the quenching of Cr3+-associated fluorescence by iron. The majority of the samples showed lamellar twinning, surface-reaching fractures, and iron staining. The material was translucent to opaque, meaning that clear observation of any other inclusions was limited.
Although the material is not considered high-quality ruby, some of the better pieces have been polished to create attractive cabochons (figure 2, right). Diamonds for Peace is currently developing a business plan to monetize this material for the benefit of the community. The GCS laboratory will continue to support Diamonds for Peace as that organization explores this new potential avenue of income for the miners of Weasua. @chapter:24


Publication Year: - Title: Demand Improves After Slow Autumn, But Challenges Remain Abstract: Demand for diamonds and gemstones in the United States appears to be picking up – spottily – after last fall’s doldrums. The U.S. Department of Commerce reported that jewelry sales increased by 14.7% in January compared to January 2012. Even more encouraging was the fact that jewelry prices were, on average, about 3% lower. The U.S. economy has been buoyed by a surging stock market, a growing (if slowly) employment market and reviving housing market.

In Asia, business at the recent Hong Kong Watch and Jewellery Show exceeded expectations, especially for diamond demand. Though there is slow growth in demand in China, demand for diamonds in Japan is improving and many retailers in both countries have been short on inventory.

Chow Tai Fook, Asia’s largest retailer, reported same-store sales decline of 3% by volume, 2% by revenue for the first two months of the year, noting that sales in Hong Kong and Macau were rising strongly, but those in Mainland China continued to soften.

Diamond producers from across the spectrum will welcome any improvement in the market. All told, 2012 was a challenging year: rough prices declined an average of 12% from 2011 and the diamond market was beset by high inventories, a credit squeeze and slow growth in demand from key consumer markets.

Although prices for rough and polished appear to have stabilized, the dilemma for diamond mining companies is how to manage the industry goal of reducing credit and inventories, and still improve revenues.

Several mining companies reported losses for 2012; others, including Rio Tinto, De Beers and Alrosa, are in the middle of very costly redevelopment projects. De Beers’ rough diamond sales plunged 16% last year, while its mine production also declined significantly.

BHP Billiton, which just sold its stake in Canada’s Ekati mine, reported that its diamond revenues declined 44% as Ekati’s production fell by more than one-third. Rio Tinto’s sales remained relatively flat, but underground operations at Argyle pushed the diamond division into a $43 million loss for 2012.

The leading producer of colored stones, Gemfields plc, is gearing up for a better year after reporting that its revenue fell 39 % to $27.7 million for the six months ending Dec. 31, 2012 compared to the same period in 2011. The company noted that it had conducted only one emerald auction during in that period, selling a total of 930,000 carats for $29.71 per carat. The company, which operates the Kagem Mine in Zambia, announced that it will hold more auctions this year as it gears up a new marketing program featuring film star Mila Kunis. @chapter:30


Publication Year: - Title: Corundum Source Types Abstract: GIA Identification and Origin Reports for ruby and sapphire include an opinion on the geographic origin of the stone, if determinable. The chart below and the downloadable PDF include more information about corundum sources and GIA’s source type classification system, detailing the relationship between source type and geographic origin.

	This information was included with GIA Corundum Reports (now GIA Identification and Origin Reports for ruby and sapphire reports) until March 2013. @chapter:0


Publication Year: - Title: Rockefeller and Fancy Blues Highlight Spring 2018 Auctions Abstract: This 8.01 ct Fancy Vivid blue diamond pendant, mounted by Moussaieff of London, drew a top bid of over $20.4 million at Christie’s May 29 Hong Kong auction. Photo courtesy of Christie’s.

The Spring 2018 auction season recovered from a slow start to post solid – if not record-breaking – prices for top fancy colored diamonds and gemstones. The biggest auction event of the season, however, was the series of sales from the estate of Peggy and David Rockefeller that brought in more than $835.7 million, most of it destined for charitable donations.

The proceeds from the jewelry portion of the estate, auctioned in conjunction with Christie’s June 12 Magnificent Jewels sale, totaled $3.12 million against a pre-sale estimate of $780,000. The top lot of the 19 pieces from the Rockefeller collection was a 5 carat (ct) Kashmir sapphire set by jeweler Raymond Yard, which sold for $372,000, and a suite of peridot and diamond jewelry that brought $348,500.

Christies’ auctioned the Rockefellers’ collection of artwork by Renoir, Rivera, Matisse, Picasso, Monet, O’Keefe and others, along with decorative arts objects over a period of 10 days in May, realizing $832.6 million for a dozen charities.

Fancy blue diamonds were the best performers in the regularly scheduled auctions. Before the season began, dealers at the March Baselworld show had numerous calls from clients who believed fancy blues were underpriced, especially in comparison to fancy pinks. After this season, that is probably no longer the case.

On May 29 Christie’s sold a GIA-graded 8.01 ct Fancy Vivid Blue diamond for nearly $20.5 million, or $2.55 million per carat. This was not a record, but an extremely strong price.

A GIA-graded 3.09 ct Fancy Intense blue diamond drew a $5.375 million bid at Christie’s April New York auction, a record for the highest per-carat price ($1.7 million) ever paid at auction for a diamond of that grade. The following day that record was shattered by a 3.37 ct cut-corner rectangular shape diamond of the same grade that sold for $6.663 million or $1.9 million per-carat. This diamond was also graded by GIA.

The high per-carat price was unusual because the diamonds were much smaller (well under 10 carats) than previous record-setting stones.

A 95.45 ct pink Ceylonese sapphire and diamond pendant sold for $2.3 million at Sotheby’s May 15 auction in Geneva. Photo courtesy of Sotheby’s.
Provenance, not size, was the defining characteristic of the most significant blue diamond of the season. The 6.16 ct Farnese Blue sold for $6.7 million at Sotheby’s Geneva May 16 auction, nearly doubling its pre-sale estimate. The diamond, graded Fancy Dark gray-blue by GIA, was from India’s famed Golconda Mine and was first given to Elisabeth Farnese, daughter of the Duke of Parma, in 1715 when she married Philippe V of Spain. The diamond was passed down through seven generations and, as Elisabeth and Phillippe’s descendants married into other European families, it traveled from Spain to France, Italy and Austria before going up for sale this year.

Fancy pink diamonds however, struggled this season, especially at the outset. At the same Sotheby’s New York sale, a 7 ct square cut Fancy Intense pink diamond, estimated at $4.2 to $5.2 million, failed to find a buyer, as did a 7.37 ct Fancy Intense orangey pink emerald cut diamond.

The 4.59 ct ruby, set by Tiffany & Co., which had come from the estate of the famed songwriter Irving Berlin, doubled its pre-sale estimate to sell for $1.15 million at Christie’s June 12 New York auction. Photo courtesy of Christie’s.
Two major rubies achieved strong prices. A 24.70 ct Burmese ruby sold for $11 million at Sotheby’s Hong Kong, while one of the most publicized lots from Christie’s June 12 New York sale was the 4.59 ct Berlin Ruby, a Burmese stone set by Tiffany and owned by the wife of the famed songwriter Irving Berlin. The gem doubled its pre-sale estimate to sell for $1.15 million. Additionally, a 95.45 ct pink Ceylonese sapphire sold at Sotheby’s May 15 auction for $2.3 million.

The first appearance of Paraíba tourmaline in an auction top 10 occurred when a private buyer paid $2.78 million at Christie’s May 29 Hong Kong auction for a pair of 7.46 ct and 6.81 ct stones respectively, to total $194,730 per carat. That was a world auction price for this gemstone.

Paraíba tourmalines rarely appear in the top 10 auction results, but this pair, weighing 7.46 cts and 6.81 cts, sold for nearly $2.8 million at Christie’s May 29 Hong Kong auction. The $194,730 per carat price was a record for Paraíba tourmaline. Photo courtesy of Christie’s.
Other significant colorless diamonds sold, all graded by GIA, included:

a 51.72 ct GIA-graded F If diamond that sold for $9.26 million at Sotheby’s May 15 auction
a 20.47 ct D Fl old mine cut diamond sold for $2.6 million, just over its low estimate, at Christie’s June 12 sale
a potentially D If 15.36 ct heart shape diamond went for $1.57 million at Christies’ New York June 12 sale

This 51.72 ct D If diamond sold for $9.26 million at Sotheby’s May 15 auction. Photo courtesy of Sotheby’s.
Despite the season’s slow beginning, Christies’ Chairman for Europe and Asia Francois Curiel noted that the “rare and beautiful continued to hold ground.” He added that the absence of large fancy colored diamonds at auction this season was a sign of their rarity, not so much as a weakness in demand.

In addition to its regularly scheduled sales, Sotheby’s has begun a series of online auctions of loose diamonds in more commercial sizes. The auction house featured five diamonds of 1, 2, 3, 4 and 5 carats (3 round, one pear shape and one emerald cut) over a two-week period starting June 14. It will hold another auction of loose diamonds in December.

An 18th century colorless diamond and natural pearl pendant that belonged to Marie Antoinette of France, estimated to sell for $1 to $2 million, will be auctioned by Sotheby’s Nov. 12 in Geneva. Photo courtesy of Sotheby’s.
Jewels from one of history’s most legendary royals, Marie-Antoinette, will be a highlight of the fall season. Sotheby’s will be selling her jewels, which include a large diamond necklace, a natural pearl necklace and a diamond and pearl pendant, as part of the Royal Jewels of the Bourbon Parma Family sale on Nov. 12 in Geneva. @chapter:30


Publication Year: 1985 Title: Winter 1985 G&G Book Reviews Abstract: “Gem Cutting: A Lapidary's Manual”
By John Sinkankas, 365 pp., illus., publ. by Van Nostrand Reinhold Co., New York, NY, 1984. US$46.95

“Jade for You: Value Guide to Fine-Quality Jade”
By John Y. Ng and Edmond Root, 107 pp., illus., Jade LV Gem Corp., Los Angeles, CA, 1984. US$49.95

“Gems and Jewels: A Connoisseur's Guide”
By Benjamin Zucker, 248 pp., illus., publ. by Thames and Hudson, New York, NY, 1984. US$50.00

“Manual of Mineralogy (After James D. Dana)”
By Cornelis Klein and Cornelius S.Hurlburt, Jr., 596 pp., illus., publ. by John Wiley & Sons, New York, NY, 1985. US$35.95

“The Barakat Gallery: A Catalogue of the Collection”
Vol. I, 319 pp., illus., publ. by The Barakat Gallery, Beverly Hills, CA, 1985.

“Benitoite: California State Gemstone”
By G. D. Louderback, 76 pp., illus., publ. by Gemmary, Redondo Beach, CA, 1985. US$5.00 @chapter:22


Publication Year: 2016 Title: The Fluid Art of Angela Conty Abstract: Figure 1. This pin/pendant features two Oregon sunstones, a Chinese freshwater pearl, and diamond accents. Carved green chalcedony and a 1.50 ct zircon complete the design. The piece is set in 14K and 18K yellow gold. Photo by Robert Weldon/GIA; courtesy of Angela Conty.

Renowned lapidary, designer, and goldsmith Angela Conty created a jewelry collection exclusively for the 2016 Tucson gem and mineral shows. We had a chance to see some of her convertible pieces at the Hotel Tucson City Center.

Ms. Conty’s artistic vision is heavily influenced by nature: Flowers, leaves, twigs, seed pods, and similar motifs are reflected in her work. The fluidity of her artistic expression strikes a perfect balance and flow between the gemstone carving and the jewelry design. Ms. Conty views her design and manufacturing process as the evolution of a work of art that often features a carved gemstone. Changes may occur when carving the stone, working the metal, or assembling the piece of art. When she has the rough in hand, she takes into consideration the stone’s shape, its best orientation, and how it would look carved and set in jewelry. As the carving progresses, the rough might take an unexpected direction, even after the metalwork is finished. She feels that lapidary work and metalsmithing must blend and harmonize in order to create the perfect balance. This means the carving or the metalwork can be continually adjusted until the carving is ready to be set. In her words, “I gather together elements, cast and constructed, and begin to solder or weld until the carving, gemstones and metalwork begin to work together, always ready to make more changes. I add, move, and remove elements to create a better integration of carving and goldwork.”

Her gemstone preferences include Australian opal, quartz, chalcedony, and her new favorite, Oregon sunstone. Her metal of choice is 18K gold, but she will sometimes use silver or 14K gold, depending on the design or the client’s preference. The relationship between the stone and metal is beautifully demonstrated in the Oregon sunstone jewelry pieces shown in figures 1 and 2, which can be worn as either brooch or pendant.

Figure 2. This 18K yellow gold convertible pendant/pin features a 46.80 ct carved Oregon
sunstone as its centerpiece. A chocolate Tahitian pearl drop and diamond accents help
frame the carving. Photo by Robert Weldon/GIA; courtesy of Angela Conty.
Ms. Conty’s combined talents in art and creative design took root more than 40 years ago at the State University of New York (SUNY) at New Paltz, where she earned undergraduate and graduate degrees in art. Her training included drawing, art history, painting, ceramics, sculpture, and silversmithing. She studied metalwork under Kurt Matzdorff, the founder of the Society of North American Goldsmiths (SNAG), and is a self-taught lapidary artist.

In 2002, Ms. Conty won second place in AGTA’s Cutting Edge Awards in the Objects of Art category. Her work has been featured in numerous publications and books. @chapter:21


Publication Year: 2018 Title: Gemstones and Sustainable Development Knowledge Hub Abstract: Figure 1. Gem cutters in Jaipur were issued masks, provided by AGTA, as part of the safety measures put in place after the Hub's assessment. Photo courtesy of Lynda Lawson.

In 2016, the Tiffany & Co. Foundation awarded the University of Delaware (UD) $350,000 over the course of two years to promote responsible practices in the colored gemstone supply chain. The grant recognizes a fine minerals collection held at the University’s Mineralogical Museum that was donated in large part by the DuPont family. Out of this effort, and under the directorship of natural resource governance specialist Professor Saleem H. Ali, grew the Gemstones and Sustainable Development Knowledge Hub (GemHub), a collaboration between UD, the University of Queensland, and the University of Lausanne. Gemologist Laurent Cartier has also been an instrumental part of this partnership. The GemHub’s goals are to perform research and to connect with initiatives identified by industry, academic, and mining communities as essential to the supply chain. The GemHub’s website, www.sustainablegemstones.org, is an excellent resource for those interested in learning about and buying sustainable and ethical stones. The areas addressed by the GemHub are colored stone mining and geology, processing and manufacturing (including cutting), gender analysis of supply chains, and economic development impact.
As of June 2018, the GemHub had launched two projects. The pilot project, initiated in Jaipur, India, in early 2018, is a study of the health issues associated with gemstone manufacturing and their solutions. This effort is in partnership with the American Gem Trade Association (AGTA) and Workplace Health Without Borders (WHWB). As part of this program, dust and silica were monitored and cost-effective best practices for improving conditions were evaluated. From these observations, educational materials on dust and silica exposure prevention and other safety precautions, such as the distribution of face masks (figure 1) were created. Noise levels have also been measured, and information on hearing loss, along with disposable hearing protection, have been disseminated. Future steps will involve measuring whether the methods that have been implemented (wetting to minimize dust, wet mopping of cutting shops) are adequate or if further measures must be taken.

Figure 2. The women miners in Madagascar use the gem testing kit, which includes tweezers, a bowl, a loupe, a dichroscope, and a scoop. Photo courtesy of Lynda Lawson.
The second project is a continuation of the work performed by Lynda Lawson, one of the GemHub’s research associates, and focuses on artisanal miner education in Madagascar. Women miners in the region of Atsimo Andrefana were taught field gemology essentials and provided with tools for identification (figure 2), even learning to make and use a simple dichroscope. The women were also taught basic lapidary skills, allowing them to make their own jewelry for sale. In the most recent training, the miners have been taught to identify characteristics of stones that are easily confused, such as topaz and quartz; women who had taken previous courses acted as peer coaches. The women have maintained their skills and tools, and the project has been extended through the end of 2018. Future steps will include working with the women to find more profitable markets for the small stones they find (primarily pink, purple, and orange sapphires).
Furthering the GemHub’s mission, the Unidel Foundation awarded a grant to the University of Delaware to develop the “Minerals, Materials and Society,” an interdisciplinary graduate certificate program due to launch at UD in 2020. The program, which will be offered online and on campus, will be designed for the multiple sectors that need to understand and address supply chain issues, including members of the jewelry industry along with geologists, economists, and government employees. The program’s signature project will be the Jewelry Development Impact Index (JDI), a project first discussed at the 2017 Jewelry Industry Summit in Tucson, Arizona and later championed by the U.S. Department of State. The JDI’s goal is to measure the gem and jewelry industry’s impact on the economic and social well-being of the countries in which they operate while establishing replicable examples of responsible activity and transparency. UD will hold a JDI Methodology Workshop on September 6, 2018 in Newark, Delaware. Those interested in participating should contact program development manager Patricia Syvrud at psyvrud@udel.edu. @chapter:28


Publication Year: 2006 Title: Spring 2006 G&G Book Reviews Abstract: “Photoatlas of Inclusions in Gemstones, Volume 2”
By E. J. Gübelin and J. I. Koivula, 829 pp., illus., hardcover, publ. by Opinio Verlag, Basel, Switzerland. US$269.50

“Schmuck Jewellery 1840–1940: Highlights Schmuckmuseum Pforzheim”
By Fritz Falk, 176 pp., 206 illus., hardcover, publ. by Arnoldsche Art Publishers, Stuttgart, 2004. US$60.00

“Working with Gemstones: A Bench Jeweler’s Guide”
By Arthur Anton Skuratowicz and Julie Nash, 128 pp., illus., publ. by MJSA/AJM Press, Providence, RI, 2005. US$34.95

To view the full section, download the PDF above. @chapter:22


Publication Year: 1999 Title: Summer 1999 G&G Lab Notes Abstract: A Rare Faceted Example of Bastnäsite
Diamond with Abundant Etch Channels
Synthetic Black Diamond
Group of 18 Synthetic Diamonds Submitted at One Time
A New Tanzanite Imitation: Synthetic Forsterite
Update on Non-Nacreous Pearls
Orangy Pink “Padparadscha” Synthetic Sapphire
Early Blue Synthetic Sapphire?

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


Publication Year: - Title: Spring 2024 G&G Available Now Abstract: To celebrate Gems & Gemology ’s 90th anniversary, our spring issue kicks off this milestone year with a variety of discoveries. With three feature articles, the latest installment of Diamond Reflections, our recap of the 2024 Tucson shows, the annual G&G Challenge quiz, and an inside look at an extraordinary platinum and garnet necklace, there’s something for everyone inside.
Mineralogy and Geochemistry of Turquoise from Tianhu East, Xinjiang, China
A team led by Ling Liu reports on turquoise from the Tianhu East deposit in northern China. The authors cover the area’s geology and the results of their studied samples, identifying a geographic origin indicator to distinguish Tianhu East turquoise from other Chinese sources.
“Ice Jade” from Guatemala
A translucent variety of jadeite jade from Guatemala has become popular in the Chinese market in recent years. Zhaoying Huang and coauthors share their study characterizing the pale green material known as “ice jade” from the Morales mine.
Nanoscale Techniques for Characterizing Gemstone Coatings: A Case Study on Synthetic Moissanite
Tsung-Jen Wu and fellow researchers study coated synthetic moissanite, using it as a basis for analyzing colored coatings on a variety of polished gemstones. The authors characterize the colored coatings and offer methods for identifying techniques used in the coating process.
Lab Notes
GIA’s global laboratory staff present their latest findings in the Lab Notes section, including a large CVD-grown diamond resubmitted after HPHT treatment, an iridescent imitation pearl resembling a pen pearl, and the first submission of a rare titanoholtite.
Micro-World
The Micro-World section, dedicated to the inner world of gemstones, features a striking cluster of trigons in diamond, pink and red epidote crystals in quartz, an exceptional iris effect in Brazilian watermelon tourmaline, and more.
Diamond Reflections
The Diamond Reflections column returns in this issue to investigate the journey of superdeep diamonds to the earth’s surface.
Gem News International
The Gem News International section starts with our coverage of the 2024 Tucson gem shows, compiling interesting finds, handcrafted designs, popular trends, and more from the shows. The GNI section continues with regular content, including a report on new beryl and emerald specimens from Newfoundland and updates on rubies from both Liberia and Mozambique.
In the Spotlight
Lastly, we spotlight an incredible collaboration from Mary van der Aa and Todd Wacks: “Garanatus: From Rough to Cut.” This AGTA Spectrum Award–winning platinum necklace features 28 of the world’s rarest garnets, totaling more than 77 carats.
Gems & Gemology Challenge
The spring issue also offers the 2024 Gems & Gemology Challenge quiz. Score 75% or better and you’ll receive a certificate of completion; earn a perfect score and your name will be listed in the Fall 2024 issue. Entries for the Challenge must be submitted online by September 1, 2024. @chapter:0


Publication Year: 2021 Title: FTIR Observation on Sapphires Treated with Heat and Pressure Abstract: Figure 1. Color-calibrated photos of blue sapphires from different origins in the study
before (top) and after (bottom) heat with pressure treatment. Photos by Sasithorn
Engniwat.
Characteristics of sapphires heated with pressure have been discussed in several gemological publications in the past few years (e.g., M.S. Krzemnicki et al., “Sapphires heated with pressure – A research update,” InColor, Vol. 42, 2019, pp. 86–90). As previously reported, heat with pressure treatment is commonly applied to Sri Lankan sapphires, in either untreated geuda or conventionally heated blue sapphires, to enhance the blue color. The material has been treated at high temperature (approximately 1200–1800°C) with an application of pressure at nearly 1 kbar, using the facilities at HB Laboratory Co., Ltd. (H. Choi et al., “Sri Lankan sapphire enhanced by heat with pressure,” The Journal of the Gemmological Association of Hong Kong, Vol. 39, 2018, pp. 16–25).
Fourier-transform infrared (FTIR) spectroscopy is considered a useful tool in revealing heat treatment of corundum (e.g., C.P. Smith, “A contribution to understanding the infrared spectra of rubies from Mong Hsu, Myanmar,” Journal of Gemmology, Vol. 24, 1995, pp. 321–335). Previous studies reported a great variability of FTIR spectra for sapphires heated with pressure, and FTIR spectra of this treated material generally showed a unique pattern of hydroxyl-related broad bands in the 2800–3500 cm–1 range, with the prominent position at around 3050 cm–1 (e.g., Krzemnicki et al., 2019). The origin of the resulting distinct IR broad bands has not been clearly determined. As discussed in Krzemnicki et al. (2019), broad bands centered at around 3050 cm–1 in sapphires heated with pressure share similar IR features observed in some acceptor-dominated corundum—heated or unheated natural materials, as well as laboratory-grown samples. (Acceptors refer to ions with the charge of –1 relative to the lattice, such as Mg2+ in corundum; see E.V. Dubinsky et al., “A quantitative description of the cause of color in corundum,” Spring 2020 G&G, pp. 2–28.)
According to a previous study (M.D.T. Phan, “Internal characteristics, chemical compounds and spectroscopy of sapphire as single crystals,” PhD dissertation, University of Johannes Gutenberg Mainz, 2015, https://d-nb.info/1075170532/34), iron (Fe3+) content in corundum can affect the position of the 3310 cm–1 IR peak. In sapphires heated with pressure, the starting material is generally limited to Sri Lankan stones. Since blue sapphires from Sri Lanka typically contain relatively low Fe concentrations (A.C. Palke et al., “Geographic origin determination of blue sapphires,” Winter 2019 G&G, pp. 536–579), the starting materials used in the study were expanded to various deposits, including Myanmar, Madagascar, Sri Lanka, Montana, Australia, Nigeria, Cambodia, and Thailand, to cover a wide range of Fe contents presented in natural corundum (figure 1). The 36 untreated and 8 conventionally heated blue sapphires were treated using heat with pressure under the conditions reported in Choi et al. (2018). Their FTIR spectra and chemical analysis using laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) were measured in the same analysis area to observe whether there was any change in FTIR spectra for different amounts of Fe.

Figure 2. Comparison of representative non-polarized FTIR spectra from sapphires heated with pressure at different Fe concentrations: (A) 275 ± 25 ppma Fe, (B) 927 ± 48 ppma Fe, and (C) 2280 ± 163 ppma Fe. Spectra are offset vertically for clarity.

Figure 3. The relationship between which band of multiple IR absorption bands is prominent for sapphires heated with pressure and Fe concentrations analyzed by LA-ICP-MS of the treated materials. The circle (●), triangle (▲), and square (■) symbols correspond to FTIR patterns A, B, and C, respectively, from figure 2.
After heat with pressure treatment, the vast majority of treated sapphires in this study (>90%) showed essentially the same hydroxyl-related IR broad bands in the 2800–3500 cm–1 range with different prominent band positions at around 3050, 3130, or 3200 cm–1 (figure 2). The IR broad band centered at around 3050 cm–1 with related bands at ~3130 and ~3200 cm–1 (figure 2A) can be observed in sapphires heated with pressure that contained Fe <700 ppma (figure 3, circle), whereas IR broad bands with comparable band intensities at around 3050, 3130, and 3200 cm–1 (figure 2B) can be found in treated sapphires with 550–1350 ppma Fe (figure 3, triangle). At relatively high Fe concentrations (>900 ppma) (figure 3, square), the FTIR spectra of sapphires heated with pressure displayed IR broad bands with a prominent band position at around 3200 cm–1 (figure 2C). In the overlapped Fe range of the samples (500–700 ppma Fe and 900–1350 ppma Fe), different IR patterns could be obtained, possibly due to heterogeneity of the samples and different characteristics of analytical techniques—bulk analysis for FTIR and spot analysis for LA-ICP-MS.
This study shows other possible FTIR spectra patterns that might be observed in sapphires heated with pressure, as well as prominent IR bands of the treated material that can shift position with different Fe concentrations. @chapter:12


Publication Year: - Title: Star Opal Abstract: Figure 1. This 2.39 ct transparent opal with a light brownish yellow bodycolor possessed a six-rayed star. Photo by Lhapsin Nillapat.

                      Opal is best known for displaying play-of-color. It may also display asterism, though star opal has only been reported from Idaho, and a perfect six-rayed star is exceptionally rare (J.V. Sanders, “The structure of star opals,” Acta Crystallographica, Vol. A32, 1976, pp. 334–338). The Bangkok laboratory recently had the opportunity to examine a transparent star opal (figure 1). The 2.39 ct light brownish yellow cabochon displayed a distinct six-rayed star.

Standard gemological testing gave a spot RI reading of 1.43 and a hydrostatically calculated SG of 2.10. When exposed to ultraviolet radiation, the stone fluoresced strong bluish white under long-wave and weak bluish white under short-wave UV. It phosphoresced green after exposure to long-wave UV. Advanced gemological testing by energy-dispersive X-ray fluorescence (EDXRF) confirmed a silica-rich material with some additional trace elements, including aluminum and iron. All of these properties were consistent with opal.

Microscopic examination revealed large parallel planes with play-of-color intersecting to form a hexagonal pattern (figure 2). This is responsible for producing the six-rayed star. This unusual stone serves as a reminder that, unlike asterism in other gem materials, the star in opal is caused by diffraction of light from faults or imperfections in the packing arrangement of silica spheres.

	Figure 2. This photomicrograph of the opal shows the intersection of large parallel planes with play-of-color, producing asterism. Photomicrograph by Charuwan Khowpong; magnified 15×. @chapter:39


Publication Year: - Title: The Type IIb De Beers Cullinan Blue Diamond Abstract: Figure 1. The 15.10 ct De Beers Cullinan Blue diamond. Photo by Towfiq Ahmed.
From the Summer 2022 issue of Gems & Gemology
Type IIb blue diamonds are extremely rare in nature. When people think of blue diamonds, the Hope diamond immediately springs to mind. The famed 45.52 ct Fancy Deep grayish blue cushion-cut treasure, now housed in the Smithsonian National Museum of Natural History in Washington, DC, has a long and fascinating history. First examined by GIA in 1960 and graded by GIA in 1988 (R. Crowningshield, “Grading the Hope diamond,” Summer 1989 G&G, pp. 91–94), it shares many special gemological characteristics with other rare type IIb (boron-containing) diamonds such as the Wittelsbach-Graff, once assumed to be cut from the same rough crystal as the Hope. Here we report another special diamond of this group.

Recently graded by GIA and the recipient of a special monograph report was a 15.10 ct (17.47 × 11.53 × 7.94 mm) Fancy Vivid blue cut-cornered rectangular step cut. Named the De Beers Cullinan Blue diamond (figure 1 and the video clip below), it was cut from a 39.34 ct rough type IIb diamond crystal mined by Petra from the Cullinan (formerly Premier) mine in South Africa. Compared to the Hope and Wittelsbach-Graff, both of which were mined in the Golconda region of India, the Cullinan has some important similarities in gemological and spectroscopic features but shows clear variations. Natural type IIb blue diamonds over 10 carats are extremely rare.

Blue color is distributed evenly throughout the stone. Visual observation under a gem microscope revealed a very clean stone. No inclusions or graining were observed. Accordingly, the diamond received a clarity grade of Internally Flawless. Under conventional long-wave and short-wave UV radiation, it showed no observable fluorescence or phosphorescence. This feature is dramatically different from that of the Hope and Wittelsbach-Graff, two large type IIb blue diamonds that exhibit strong and prolonged red phosphorescence to conventional short-wave UV radiation.

Figure 2. The mid-infrared spectrum of the type IIb De Beers Cullinan Blue diamond.
The absorption spectrum in the mid-infrared region showed typical absorption features related to boron in diamond, such as strong absorption at ~2800 cm–1 and a weak absorption peak in the range of 1332–1200 cm–1 (figure 2). The intensities of these absorptions indicated a high concentration of uncompensated boron of ~0.33 ppm. Natural type IIb diamonds typically contain 0.24–0.36 ppm (E. Gaillou et al., “Study of the Blue Moon diamond,” Winter 2014 G&G, pp. 280–286). The diamond’s boron concentration is close to that in the Hope (~0.36 ppm) and higher than that in the Wittelsbach-Graff (~0.19 ppm). Absorption from boron is the main contributor of color in natural type IIb diamonds.

Figure 3. Observed with cross polarized light was a strong tatami strain pattern with a dark gray color. Photo by Madelyn Dragone.

Figure 4. Under very strong short-wave UV, a weak aqua blue flourescence with a subtle network of dislocations was observed (top). After exposure, a weak pinkish red phosphorescence was observed (bottom). Images by Stephanie Persaud.
Observation with a gemological microscope equipped with crossed polarizers revealed a clear tatami pattern with a dark gray color (figure 3). Both the Wittelsbach-Graff and the Hope have different patterns and higher interference colors, a good indication that the De Beers Cullinan Blue has a much less distorted lattice structure. Under very strong short-wave UV, this diamond showed a weak aqua blue fluorescence with a subtle network of dislocations in the crystal structure, a pattern clearly different from the tight mosaic patterns observed in the Hope and the Wittelsbach-Graff (figure 4) (Gaillou et al., 2014).

	The Type IIb De Beers Cullinan Blue Diamond

These blue diamonds are among the rarest of gems. Recent research (E. Smith et al., “Blue boron-bearing diamonds from Earth’s lower mantle,” Nature, Vol. 560, No. 7716, 2018, pp. 84–87) has demonstrated that their boron derived from pieces of the earth’s crust sinking to the extremely deep depths of diamond formation. The gemological characteristics of the De Beers Cullinan Blue suggest it is one of these superdeep diamonds. Its combination of Fancy Vivid blue color grade in a step cut (a cut that does not enhance color, unlike other faceting styles) (see video), 15.10 ct weight, and internally flawless clarity grade is exceptionally rare. It will remain one of the world’s most important diamonds. @chapter:31


Publication Year: 2023 Title: Precious metals and gemstones traded at HK$120,000 or more must be registered with Hong Kong Customs. Abstract: Hong Kong, besides being a financial hub, has long enjoyed economic and trade freedom. This includes free movement of finances, facilitating business transactions conveniently and swiftly. Given Hong Kong's jewelry and gem market is lucrative, evidenced by the substantial value of gem and jewelry exports (excluding gold) from Thailand to Hong Kong, totaling over 713.94 million US dollars from January to October 2023 alone, compliance with anti-money laundering and counter-financing of terrorism regulations became imperative.

Starting April 1, 2023, the Hong Kong Customs and Excise Department announced new criteria for representatives in this sector, who must register or submit forms, as per the following cases:

Groups Required to Register:
1.1. Dealers in Precious Metals and Stones (DPMS) in Hong Kong must register with the Hong Kong Customs and Excise Department.
1.2. Non-Hong Kong Precious Metals and Stones Dealers must submit a "Cash Transaction Report," including travel details, representative or agent information, customer details, and business activities related to Specified Cash Transactions in Hong Kong to the Hong Kong Customs and Excise Department
Criteria for registration are divided into 2 types:

2.1 Distributors engaged in "Specified Transactions," such as transactions related to non-cash payments totaling at least 120,000 Hong Kong dollars or equivalent in other currencies, excluding "Specified Cash Transactions," such as transactions involving cash payments totaling at least 120,000 Hong Kong dollars or equivalent in other currencies in Hong Kong.

2.2 Distributors engaged in both "Specified Transactions" and "Specified Cash Transactions" in Hong Kong
definitions of the terms:

3.1 "Dealer in Precious Metals and Stones" refers to any individual engaging in one of the following activities:

(1) Trading (including buying and selling), exporting, or importing precious metals, gemstones, or valuable products.
(2) Manufacturing, refining, or processing to add value to precious metals, gemstones, or valuable products.
(3) Dealing with securities backed by assets.
(4) Acting as an intermediary for activities in (1)-(3).

Except for individuals conducting logistics service businesses that solely import or export precious metals, gemstones, or valuable products in the normal course of their business operations.

3.2 "Non-Hong Kong Precious Metals and Stones Dealer" is an individual or legal entity engaging in buying and selling precious metals and gemstones in Hong Kong, meeting one of the following criteria:

(1) Not ordinarily residing in Hong Kong.
(2) A non-natural person established or incorporated outside Hong Kong that is not a foreign company registered in Hong Kong as specified in Section 2(1) of the Companies Ordinance (Cap. 622).
(3) Does not have a business premises in Hong Kong.
(4) The total number of days conducting precious metals and stones business in Hong Kong does not exceed 60 days per calendar year.

3.3 Controlled Goods are categorized into 4 types:

(1) Precious Metals: Gold, Silver, Platinum, Iridium, Osmium, Palladium, Rhodium or Ruthenium, both refined and unrefined.
(2) Precious Stones: Diamonds, Sapphires, Rubies, Emeralds, Jade, or Pearls, whether natural or otherwise.
(3) Precious Products: Jewelry or watches made from or attached to precious metals, gemstones, or both.
(4) Securities with asset-backed certificates: Certificates or securities representing ownership rights in precious metals, precious stones, or precious products, excluding:
(4.1) Any securities, futures contracts, interests in collective investment schemes, structured products, or OTC derivative products as specified in the Securities and Futures Ordinance (Cap. 571).
(4.2) Virtual Assets.

Suggestions/Comments from the Thai Gem and Jewelry Representative:

Thailand's dealers in precious metals and gemstones should thoroughly study the detailed information before engaging in trade activities in Hong Kong. Non-compliance may result in a maximum fine of HK$50,000 or imprisonment for 3 months @chapter:30


Publication Year: - Title: Spring 2018 Auctions Off to Cautious Start Abstract: The mysterious 6.16 Fancy Dark gray-blue Farnese Blue diamond, graded by GIA, will be auctioned by Sotheby’s May 15 in Geneva. Mined at Golconda, the legendary source of the Hope Diamond, this jewel was given to Elisabeth Farnese upon her marriage to Phillippe V of Spain in 1714. Unlike other royal jewels, this diamond was kept in a small wooden box away from the public eye for more than two centuries until this sale. The French script on the silver plaque on the box reads: “Remarkable blue brilliant. This historical stone was offered by the Philippine Islands to Elisabeth Farnese, Queen of Spain, wife of Philippe V, great-grandfather of the Comte of Villafranca, current owner of that stone.” Photo courtesy of Sotheby's.

The record-breaking array of major fancy colored diamonds and large colorless diamonds are less evident this spring auction season, as buyers around the world turn more cautious.

While some impressive diamonds and colored gemstones are still being offered in the top venues – Hong Kong, New York and Geneva – the emphasis is on classic pieces from jewelry houses, such as Cartier, Boucheron, JAR and Van Cleef & Arpels, and smaller fancy colored diamonds.

The first major sale of the season, Sotheby’s April 3 Hong Kong auction, saw most of the top lots fail to sell. The highlight of the auction was the Circle of Heaven, a jade bangle estimated to sell for between $10.2 million and $12.8 million, failed to find a buyer. Prices for top jade have softened, but the wide publicity Sotheby’s provided for this piece indicated that the house jewelry department was confident it would achieve that price.

Also not sold: a 17.63 ct D Flawless diamond, estimated at $2.8 million, and a 14.18 ct Fancy blue diamond.

The 5.01 ct Fancy Vivid purplish pink diamond offered at the auction sold for $2.5 million, which was well below what similar diamonds have sold for in previous sales.

Christie’s April 17 New York auction featured a GIA-graded 8.42 ct Fancy Intense pink estimated at $4 to $6 million, which sold for $ 5 million, but the majority of top lots were signed period and modern pieces from the major jewelry houses. Another top lot was a ring by Paris designer JAR featuring a GIA-graded 22.79 ct D Flawless l “elongated oval” cut diamond estimated at $2.5 to $3.5 million, which went for $2.8 million. In addition, there were about 20% fewer lots in this sale than in previous spring New York auctions..

This 51.71 ct D Flawless Type IIa round diamond is expected to bring between $7 to $9 million at Sotheby’s May 15 auction in Geneva. The diamond is one of two 50-carat-plus diamonds of that grade offered at the sale. Both were graded by GIA. Photo courtesy of Sotheby's
Sotheby’s is betting that buyers will pay $7 to $9 million each for a pair of 50 ct-plus D Flawless Type IIa diamonds highlighting its May 15 Geneva sale. One diamond is a 51.71 ct round brilliant while the other is a 50.39 ct oval shape, according to GIA grading reports.

The house is also offering the historic GIA-graded 6.16 ct Fancy dark gray-blue diamond, known as the Farnese Blue. The royal diamond, originally from India’s famed Golconda region that produced the Hope Diamond, has a history almost as fascinating. The diamond was a gift to Queen Elisabeth Farnese of Spain by her husband King Philippe V in 1714. It was passed to the queen’s son, Philippe, Duke of Parma, and then through various Italian noble families and ultimately to the Habsburg family in Austria – all the while keeping its existence secret from anyone outside the immediate families. The diamond is expected to sell for $3.7 to $5.3 million.
DIAMONDS
De Beers announced that its April rough diamond cycle totaled $520 million in sales, which is about 12% lower from the same period last year and 8% down from the previous cycle.

The company did not announce a price increase, though some press reports indicated that prices were slightly higher in some categories. De Beers often adjusts prices slightly in the mix of goods offered to clients.

De Beers’ CEO Bruce Cleaver noted that the rough market is healthy and “focusing on restocking, following healthy consumer demand for diamond jewelry in the U.S. and China.”

Russia’s Alrosa, the world’s largest diamond producer by volume, reported that its March sales total was $559.5 million, which also includes polished diamonds from special tender auctions. The total was $18.4 million higher than February because of increased sales of large diamonds, according to Alrosa deputy CEO Yury Okoemov.

Russia’s first quarter diamond sales totaled $1.61 billion, $1.58 of which were rough diamonds, Okoemov noted. @chapter:30


Publication Year: - Title: Winter 2017 G&G: Cullinan-Like Superdeep Diamonds, the Artistic  Exquisite Gem Carvings of the Dreher Family, and Matrix-Matched Corundum Standards Abstract: The rough diamond shown on the cover, the 812 ct Constellation, was recovered from the Karowe mine in Botswana in November 2015. It is currently the sixth-largest gem-quality rough diamond ever recorded. It was sold in May 2016 for $63.1 million, the highest price paid for a rough diamond to date. The size, near absence of inclusions, low nitrogen content, shape, and surface texture place it in a special variety known as CLIPPIR diamonds, which are reviewed in the lead article in this issue. Diamonds such as the Constellation, which grow in a geologically distinct way, convey valuable information about the earth’s deep mantle. Photo by Jian Xin (Jae) Liao.

From diamonds that originate deep within the earth’s mantle to pearls cultured along Australia’s eastern coastline, the Winter 2017 issue of Gems & Gemology reports on the many facets of the gemological world. Articles include a look at the origin of Cullinan-like “superdeep” diamonds, the lifelike gem carvings of Gerd and Patrick Dreher, and the characteristics of Australian akoya cultured pearls. The Winter issue also introduces GIA’s new calibration standards sets  for analyzing the chemistry of corundum, compares two different types of detectors in microradiographic imaging of pearls, and features a chart showing inclusions in natural, synthetic, and treated ruby.
THE VERY DEEP ORIGIN OF THE WORLD’S BIGGEST DIAMONDS

Rough CLIPPIR diamonds have physical features akin to the historic Cullinan diamond, which forms the “C” of the CLIPPIR acronym. The size distribution for this variety of diamond is skewed toward large sizes, with the examples shown here ranging from 14 to 91 carats. In rough form, CLIPPIR diamonds are irregularly shaped rather than well-formed crystals and sometimes appear to be broken fragments of once larger diamonds. Photo by Robert Weldon/GIA; courtesy of Gem Diamonds Ltd.
The lead article of the Winter 2017 issue reviews the remarkable diamonds found deep in the earth’s convecting mantle. In a follow-up to his December 2016 article in Science magazine, Evan Smith and coauthors examine 83 of these large, pure, Cullinan-like diamonds, known for their high clarity and D color grades. The samples used in this paper, along with their inclusions and other properties, provide a glimpse into the earth’s geologic formation.
GEM VIRTUOSOS: THE DREHERS AND THEIR EXTRAORDINARY CARVINGS

This Gerd Dreher lily carving (2005) is from a single piece of Brazilian agate and measures 11.0 cm in length. His skills are on exhibit through his use of the material and his technique, such as the curled petals that demonstrate a wealth of detail even on their undersides. The leaf, stamen, and enameled pistil accents are crafted from 18K gold and set with diamonds. Patrick Dreher’s citrine mouse (2015), 6.0 cm in length, shows attention to the animal’s stance and demeanor as well as fine detail in the carving of the fur. Photo by Robert Weldon/GIA, courtesy of the William F. Larson family.
The German town of Idar-Oberstein is known for its gem cutting and carving industry. Coauthors Robert Weldon, Cathleen Jonathan, and Rose Tozer explore the town’s rich history and the carving tradition of the Dreher family, which has passed down its skills through thirteen generations. The work of contemporary masters Gerd and Patrick Dreher is the focus of this article, which is accompanied by online videos and slideshows.
AKOYA CULTURED PEARL FARMING IN EASTERN AUSTRALIA

A bracelet showing naturally colored blue, cream, yellow, and silver akoya cultured pearls from Broken Bay Pearls. Photo courtesy of Broken Bay Pearls Pty Ltd.
For two decades, akoya cultured pearls in a variety of colors have been produced from P. imbricata fucata mollusks on Australia’s eastern coast. In this article, Laura M. Otter and her coauthors detail the production and conduct the first gemological and mineralogical study of these pearls. Their study concludes that colored Australian akoyas can be separated from pearls produced by other mollusk species.
ACCURATE REPORTING OF KEY TRACE ELEMENTS IN RUBY AND SAPPHIRE USING MATRIX-MATCHED STANDARDS

One of GIA’s new LA-ICP-MS corundum calibration standards sets (set number 1); the epoxy disk containing the set is 1.5 inches in diameter. NIST SRM 610 and 612 glass standards are included to account for trace and non-trace elements, such as those found in inclusions, that were not incorporated into the synthetic sapphire crystals grown for standards. Photo by Jennifer Stone-Sundberg.
Trace element analysis is crucial to determining geographic origin of corundum. Jennifer Stone-Sundberg and a team of researchers have developed highly accurate calibration standards for chemical analysis at GIA using the LA-ICP-MS technique. These sets are designed for use in basic research and geographic origin reporting of ruby and sapphire.
REAL-TIME MICRORADIOGRAPHY OF PEARLS: A COMPARISON BETWEEN DETECTORS

Structures and principles of operation for an II (left) and an FPD (right). Modified after Ide et al.
Over the past twenty years, real-time X-ray microradiography (RTX) has largely replaced film-based X-ray imaging in the examination and identification of pearls. Stefanos Karampelas and his colleagues discuss the benefits and drawbacks of two different types of detectors used with RTX units.
CHART OF INCLUSIONS IN NATURAL, SYNTHETIC, AND TREATED RUBY

These rubies, a 16.68 mm rough and a 2.72 ct cushion cut, are from Myanmar. Photo by Robert Weldon/GIA, courtesy of the William F. Larson collection.
The third wall chart in a series documents inclusions often found in natural, synthetic, and treated emerald. Inclusion specialists Nathan Renfro, John Koivula, and Jonathan Muyal provided the 30 detailed photomicrographs in this chart.
LAB NOTES

This alexandrite cabochon appears brownish green in fluorescent light (left) and brownish purple in incandescent light (right). The cabochon shows chatoyancy under both forms of illumination due to light reflection from the shallow plane of dense fine parallel needles. Photos by Shunsuke Nagai.
Bulletins from GIA’s labs around the world include a cat’s-eye alexandrite with a unique inclusion pattern, a synthetic moissanite imitating rough diamond, and two natural sapphires with synthetic ruby overgrowth.
MICRO-WORLD

This Ethiopian opal contained an interesting inclusion scene consisting of a string of octahedral pyrite crystals and aragonite spheres. Photomicrograph by Charuwan Khowpong; field of view 1.40 mm.
G&G’s section on the inner world of gemstones features entries on aragonite spheres in Ethiopian opal,  twinned calcite inclusions in Mogok ruby, and shattuckite in quartz.
GEM NEWS INTERNATIONAL

Sixteen samples of facet-quality ruby (0.8–7.1 ct) from Longido, Tanzania. Photo by Sasithorn Engniwat.
The GNI section features a preliminary look at facet-grade ruby from Longido, Tanzania; an update on the Foxfire rough diamond, mined from Canada’s Diavik mine in 2015; and the testing of hydrophane opals dyed pink and blue.
2017 DR. EDWARD J. GÜBELIN MOST VALUABLE ARTICLE AWARD
G&G’s Most Valuable Article Award invites the journal’s readers to vote on the three most important articles from the previous year. Each completed ballot is entered into a drawing to win a one-year subscription to Gems & Gemology. To qualify for the drawing, please submit your votes for the 2017 MVA Award by Monday, March 12, 2018. @chapter:29


Publication Year: - Title: GIA Field Gemologists Seek Gems in Luc Yen, Vietnam Abstract: Hunting for Gems in Vietnam

	Join the hunt for Vietnam’s ruby, sapphire, and spinel with GIA field gemologists.

	In this video, you’ll venture into Vietnam’s gem-rich interior and, along with GIA Field Gemologist Vincent Pardieu and his team, climb Luc Yen’s treacherous limestone mountains in search of the region’s gems. You’ll also visit the bustling gem markets of Luc Yen town and skim the waters off Ha Long Bay to visit an akoya pearl farm.

	Pardieu points out that the annual expedition to Vietnam isn’t just a good occasion to collect new reference samples and witness mining and trading activity. It also serves to train and evaluate young gemologists hoping to join the Bangkok GIA Field Gemology department.

	Luc Yen is a mountainous district located in the north of Vietnam’s Yen Bai province. It’s approximately 155 miles (250 km) northwest of Vietnam’s capital city, Hanoi, about a 4- to 5-hour journey by road.

	Its main city, Yen The, is also known as Luc Yen. Once a sleepy provincial area, Luc Yen was the scene of a rich discovery of ruby, sapphire, and spinel in 1987. Yen The is still Vietnam’s premier gem trading district, although the activity is much reduced since the heady days of the 1980s and 1990s.

	Luc Yen is an area of rugged beauty—steep, almost conical limestone mountains rise out of lush, fertile plains. This is karst topography, formed when rainfall dissolved soluble rocks like limestone and created underground drainage systems with sinkholes and caves. These features—combined with the hot climate and abundant vegetation—make it exhausting for the GIA team to reach the mines, where miners recover ruby, sapphire, and spinel from primary and secondary deposits using small-scale artisanal methods. At one point, the high temperatures and humidity force the team to seek shelter: “It’s just superhot…people are not working…” Pardieu explains.

	Some of the rubies from that 1987 discovery rival those from Mogok, Myanmar. “The stones that were mined 20 years ago are still in the trade,” says Pardieu, “and they may come to the laboratory one of these days, so it is important for us at GIA to come here and collect samples from small-scale miners and to study them…so we’ll be able to identify the stones that were mined today, in the future, or in the past.”

	The GIA team also visited the valleys beneath the karsts where local farmers mine gem-quality red, pink, purple, and blue spinel from placers along the streams and from alluvial deposits.

	You’ll also join the GIA team as they explore the gem markets of Yen The. As Pardieu says, “That’s usually the first step when I come in an area. We go to the merchants in order to have an idea of what is available.” This includes a visit to the skilled artisans who create Vietnam’s remarkable gemstone paintings. They use tiny stones in a variety of colors to create intricate scenes modeled after Vietnamese artworks.

	Finally, the team makes the journey to Ha Long Bay. It’s about six hours east of Yen The, a drive of about 224 miles (360 km). This is the heart of Vietnam’s pearl-culturing area.

	This GIA Field Expedition (FE54) took place in June 2014. Besides Pardieu, the participants were cameramen Didier Gruel and Philippe Brunot and expedition members Victoria Raynaud, Stanislas Detroyat, and Marie Daufresne. @chapter:25


Publication Year: 2024 Title: Fluorite in Brazilian Alexandrite Abstract: An octahedral fluorite crystal in a 1.25 ct Brazilian alexandrite. Photomicrograph by Hikaru Sato; field of view 2.37 mm.
The author recently examined a 1.25 ct transparent oval modified brilliant alexandrite. The stone possessed a single crystal inclusion in the shape of a perfect octahedron (see above). Raman analysis identified the crystal as fluorite (CaF2), which supported the alexandrite host’s origin determination of Brazil.
Fluorite crystals are occasionally found in Brazilian alexandrite (Z. Sun et al., “Geographic origin determination of alexandrite,” Winter 2019 G&G, pp. 660–681). However, they are often rounded in shape and rarely perfectly octahedral like the observed crystal here. @chapter:13


Publication Year: 2023 Title: Iridescent Inclusion in Brown Diamond Abstract: This iridescent ferropericlase crystal with a stress halo measuring approximately 0.7 mm was trapped inside a light brown diamond. Photomicrograph by Kyaw Soe Moe; field of view 1.58 mm.
The iridescent crystal inclusion in the 1.07 ct light brown type IIa diamond in the figure above was identified by Raman spectroscopy as ferropericlase. Ferropericlase, (Mg,Fe)O, can originate from either shallow (lithospheric) or deep (sublithospheric) depths within the earth. A stress halo was developed around the crystal by temperature and pressure changes during the ascent to the earth’s surface. The colorful iridescence may have been caused by light interference at a thin film trapped between the inclusion and the host diamond. It is rare to see ferropericlase as an inclusion in diamond, especially such a large crystal. @chapter:35


Publication Year: 2015 Title: New Production of Brazilian Emerald from Minas Gerais Abstract: Figure 1.  This exceptional 9.22 ct emerald is from Belmont’s underground mine. Photo by Robert Weldon/GIA; courtesy of the Belmont mine.

At the GJX show, Marcello Ribeiro (Belmont Mine, Itabira, Brazil) showed us production from Belmont’s underground mine, including one especially fine 9.22 ct stone (figure 1). As a GIA team visited Belmont in April 2014, it was interesting to see the gems from this relatively new part of the mining operation for sale at the show.

Originally the site of a cattle ranch, Belmont yielded its first emeralds in 1978 (H.A. Hänni et al., “The emeralds of the Belmont Mine, Minas Gerais, Brazil,” Journal of Gemmology, Vol. 20, Nos. 7–8, 1987, pp. 446–457). Since then, the mine has expanded to include both open-pit and underground operations with a highly sophisticated recovery plant. Mining is supported by a comprehensive geological survey program. To date, more than 15 km (9.3 miles) of 3.8 cm (1.5 inch) diameter cores have been drilled. Geological surveys indicated that a 300-meter-thick schist layer—with emerald potential—underlies much of the property, including the recovery plant. Core sampling defined the extent and depth of the emerald ore body and proved the viability of an underground mine at Belmont. Sampling the underlying rocks also helped plan the mine’s mechanical structure by showing which layers would be capable of supporting underground tunnels.

The underground mine is accessed via a 666-meter ramp that allows removal of up to 30 to 40 truckloads of ore per day using large commercial trucks (figure 2). At the time of our visit, approximately 10 to 15 truckloads per day (about 200 tonnes) were being taken to the recovery plant. The underground workings deliver a ratio of one tonne of ore to one tonne of waste. Each tonne of ore yields about two grams of rough emerald. On average, those two grams of rough produce two carats of faceted emeralds. By contrast, the ratio for the current open pit is only one tonne of ore per 11 tonnes mined. The rest is overburden or waste. There is clearly the capacity for many more years of productive mining at Belmont.

Figure 2. A full-size truck navigates the tunnels of Belmont’s underground mine. From the outset, the operators determined this would be a high-capacity, ramp-style mine. Photo by Duncan Pay/GIA; courtesy of the Belmont mine.
During the same April 2014 trip, GIA field gemologists visited the Montebello mine, near Nova Era. At this year’s GJX show, Sergio Martins (Stone World, São Paulo) showed us new production from that mine (figure 3). These gems were in the 2–4 ct range, bright with strong color and good luster.

Figure 3. This array of gems in the 2–4 ct range from the Montebello mine shows the bright, vivid appearance of high-quality emeralds from Nova Era. Photo by Robert Weldon/GIA; courtesy of the Montebello mine.
The Montebello mine is adjacent to the independent miners’ village of Capoeirana, about 6 km (3.7 miles) from Nova Era. Capoeirana is about 26.5 km (16.5 miles) east of Itabira. Unlike the larger mechanized operation at Belmont, the area around Capoeirana hosts a variety of small-scale mining activities by these independent miners, known as garimpeiros. The Montebello mine is perhaps the largest, employing 15 of them.

Emeralds were first discovered near here in 1988 (D. Epstein, “The Capoeirana emerald deposit near Nova Era, Minas Gerais, Brazil,” Fall 1989 G&G, pp. 150–158; www.gia.edu/gems-gemology/fall-1989-brazil-emeralds-epstein). The exploration that led to a mining boom in nearby Capoeirana was triggered by the discovery of emerald at Belmont. Production has dwindled in Nova Era, due in part to the 2008 global economic recession and the greater depths—often more than 100 meters—required to reach the emerald mineralization (A. Lucas, “Brazil’s emerald industry,” Spring 2012 G&G, pp. 73–77; www.gia.edu/gems-gemology/spring-2012-brazil-emerald-lucas). Emerald mineralization in the surrounding area appears to start in Nova Era and finish at the Belmont mine. Between them is another—currently unworked—mine, called Piteiras, which Martins used to operate. Mining stopped there due to ownership disputes that the parties hope will be resolved shortly.

At Montebello, the main elevator shaft descends 130 meters. At the time of GIA’s visit, miners had sunk a new vertical shaft about 40 meters below the level of the existing main shaft (figure 4). It follows a new vein that dips steeply underground. Neighbors in an adjacent mine have already found a productive vein at about that level. When the miners sunk their shaft, they located a seven-meter-thick seam of soft black schist underlain by granite. Emeralds occur in the boundary where the quartz meets the schist. The dark color of the schist and the presence of quartz are good indicators for emeralds and pale beryl crystals. From this new 40-meter shaft, they are driving a new horizontal tunnel out into the schist. The miners plan to expand the shaft and install a second elevator. The miners added that Montebello’s stones appear to increase in size and color with depth.

Figure 4. At Montebello, the miners have sunk a new shaft to follow a promising vein of emerald-bearing schist to deeper levels in the mine. The base of the new shaft is 170 meters below the surface. Photo by Andy Lucas/GIA; courtesy of the Montebello mine. @chapter:1


Publication Year: 2015 Title: Orange Faceted Eosphorite Abstract: Figure 1. This 5.85 ct orange mixed cut was a rare faceted eosphorite. Photo by Robison McMurtry.

The Carlsbad laboratory recently examined a 5.85 ct transparent orange oval mixed cut for identification services (figure 1). Standard gemological testing showed an RI of 1.640 to 1.667; the hydrostatic SG was 3.12. The stone showed yellow and reddish orange pleochroism. Fluorescence was inert to long-wave and short-wave UV radiation. The most distinctive internal characteristic, revealed by microscopic examination, was the presence of multiphase inclusions (figure 2), suggesting a formation process with the presence of water, such as pegmatitic and hydrothermal processes.

Figure 2. Multiphase primary fluid inclusions are seen in the eosphorite, indicating a
pegmatitic or hydrothermal formation process. Photomicrograph by Nathan Renfro;
field of view 1.26 mm.
Raman spectroscopy confirmed that the stone belongs to the childrenite-eosphorite mineral series (figure 3), with intense peaks observed at 970 and 1011 cm–1. These peaks are attributed to the P-O (phosphorus-oxygen) stretching vibrations (R. L. Frost et al., “Vibrational spectroscopic characterization of the phosphate mineral series eosphorite-childrenite-(Mn,Fe)Al(PO4)(OH)2·(H2O),” Vibrational Spectroscopy, 2013, Vol. 67, pp. 14–21). This mineral series has a stoichiometric formula (Mn,Fe)Al(PO4)(OH)2·(H2O). Visible absorption spectroscopy revealed that the stone’s orange color results from the combination of Fe and Mn (M.A. Hoyos et al., “New structural and spectroscopic data for eosphorite,” Mineralogical Magazine, 1993, Vol. 57, pp. 329–336).

Figure 3. Raman analysis of the eosphorite in the 2000–200 cm–1 range showed a typical
spectrum of phosphate oxyanions. The 970 and 1011 cm–1 peaks are assigned to the P-O
stretching vibration, while the 1038 and 1055 cm–1 peaks are attributed to the PO3–4
stretching vibration. The 405, 473, 561, 595, and 618 cm–1 peaks are associated with
the PO4 and H2PO4 bending modes.
Energy-dispersive X-ray fluorescence (EDXRF) analysis revealed a composition of 25.10 wt.% Al2O3, 31.74 wt.% P2O5, 15.46 wt.% MnO, 11.47 wt.% FeOtot, 0.49 wt.% MgO, 0.25 wt.% CaO, and 15.50 wt.% H2O (water weight percent is assumed from references). The stone contains 55.3 mol.% eosphorite and 40.5 mol.% childrenite. The calculated formula is
(Mn0.48Fe0.35Ca0.01Mg0.03)(Al)1.09(P0.99 O4)(OH)2·0.91(H2O), which indicates an intermediate member of the childrenite-eosphorite series with predominance of the Mn phase. As a result, the stone should be classified as eosphorite.

Eosphorite is the manganese-rich end member of the childrenite-eosphorite series, formed worldwide in pegmatites (T. J. Campbell and W. L. Roberts, “Phosphate minerals from the Tip Top mine, Black Hills, South Dakota,” Mineralogical Record, 1986, Vol. 17, pp. 237–254) or by hydrothermal phosphatization of metasediments and associated with the intrusion of granites (R. S. W. Braithwaite and B. V. Cooper, “Childrenite in South-West England,” Mineralogical Magazine, 1982, Vol. 46, pp. 119–126). This was the first faceted eosphorite examined by GIA’s Carlsbad laboratory. @chapter:13


Publication Year: 2023 Title: The history of gemstones in Chanthaburi_18 Abstract: The reason why the Gula(Kula) people from Shan State  had knowledge and expertise in gemstone crafting was due to the historical legacy of gemstone production in ancient times, particularly in Mogok, which dates back to the year 2160 of the Buddhist Era, corresponding to the late Ayutthaya period. During this time, the East India Company of England had significant influence in Burma (Myanmar), including in mining activities related to gemstones in Mogok. The gemstone production in Mogok contributed to the knowledge of gemstones among the Gula(Kula) people and Thai traders since that period. @chapter:25


Publication Year: 2002 Title: Fall 2002 G&G Book Reviews Abstract: “From Mine to Mistress: Corporate Strategies and Government Policies in the International Diamond Industry”
By Chaim Even-Zohar, 555 pp., publ. by Mining Journal Books Ltd., Edenbridge, England. US$495.00

“Light & Stone: Highlights from the Scott Gem Collection”
Photography by Harold and Erica Van Pelt, commentary by Peter C. Keller and Michael M. Scott, publ. by the Bowers Museum of Cultural Art, Santa Ana, California, 2002. US$25.00

“Gemstones Quality and Value, Volume 2”
By Yasukazu Suwa, 144 pp., illus., publ. by Sekai Bunka Publishing Inc., Tokyo, (2nd ed., English translation) 2002. US$95.00

“Murzinka: Alabashka Pegmatite Field”
By Valentina I. Popova, Vladimir A. Popov, and Alexander A. Kanonerov, illus., 136 pp., Vol. 5 of the Mineralogical Almanac series, publ. by Ocean Pictures Ltd., Russia, 2002. US$39.95

“Gemstones and Other Unique Minerals and Rocks of Wyoming: A Field Guide for Collectors”
By W. Dan Hausel and Wayne M. Sutherland, illus., 268 pp., Bulletin 71, Wyoming State Geological Survey, Laramie, 2000. US$20.00

To view the full section, download the PDF above. @chapter:7


Publication Year: 2008 Title: Gota de Aceite: Nomenclature for the Finest Colombian Emeralds Abstract: The finest and rarest emeralds are sometimes said to have an optical effect called gota de aceite. This term describes an aspect of emerald clarity that is associated with Colombian emeralds. Yet overuse has separated the term from its actual meaning. This article reports on the gemological causes of the gota de aceite optical effect and defines the phenomenon. @chapter:8


Publication Year: 2019 Title: The Effect of Low-Temperature Heat Treatment on Pink Sapphire Abstract: Figure 1. Color-calibrated photos of samples before (left) and after (right) heat treatment in air at 800°C for 160 minutes. Photos by Sasithorn Engniwat.
GIA has been studying low-temperature heat treatment on sapphires and rubies for the last five years. This report presents preliminary results of low-temperature heat treatment on pink sapphires, a procedure commonly used to reduce blue color components or zones. In this study, we selected 11 samples from Ilakaka, Madagascar, and one sample from Ratnapura, Sri Lanka, that were suitable for heat experiments—in other words, samples showing a 3309 cm–1 peak in FTIR with an absorption coefficient intensity of at least 0.04 cm–1 before heat treatment and fewer inclusions or fractures. From previous studies (S. Saeseaw et al., “Update on ‘low-temperature’ heat treatment of Mozambican ruby: A focus on inclusions and FTIR spectroscopy,” GIA Research & News, April 30, 2018), we know that when the 3309 cm–1 peak is high enough, the 3309 series will develop after heat treatment. While the samples’ bodycolor was predominantly pink, they all had a blue or purple modifier, as seen in figure 2 (left). Their fluorescence under UV radiation was pink, with a stronger reaction in long-wave UV than short-wave. The sapphires from Madagascar contained abundant zircon (both as single crystals and clusters), stringers of particles, short needles, growth tubes, and other minerals such as monazite. The Sri Lankan stones revealed short and long needles, fingerprints, and some single zircon crystals with tension halos.

Figure 2. Comparison of FTIR spectra before (blue) and after (red) heat treatment on an unoriented pink sapphire from Madagascar.
In this experiment, the samples were heated in air at 800°C for 160 minutes. These are the minimal heating conditions for significantly reducing blue color in Mozambique rubies (Saeseaw et al., 2018). After heating, the blue component was reduced and the samples were a purer pink (figure 2, right). Their fluorescence reactions remained the same, and no chalky fluorescence was observed under short-wave UV. Most of the zircon inclusions remained unaltered, but in a few cases some small discoid fractures developed. Some of the other crystals showed tension fractures, but we noticed that only some of the mica or monazite crystals were affected by low-temperature treatment. Thus, not every stone will show clear signs of heat treatment, especially when heated only at low temperature. As reported previously, advanced techniques such as FTIR are useful in detecting heat treatment, and we applied it to these samples.
Before heating, all 12 samples exhibited a single peak at 3309 cm–1. After heat treatment, they showed a decreased 3309 cm–1 peak, while eight Madagascan and one Sri Lankan sample had developed a peak at 3232 cm–1. No 3185 cm–1 peak was detected in this experiment (see figure 2). The intensity of the peaks at 3309 and 3232 cm–1 was quite low after heat treatment; maximum intensity was only about 0.04 and 0.01 cm–1, respectively. In addition, we collected FTIR spectra on 120 unheated pink sapphires from Madagascar and 80 samples from Sri Lanka, and no 3232 cm–1 peak was detected. We concluded that the 3232 cm–1 peak is only found in heated pink sapphires. @chapter:12


Publication Year: 2023 Title: The history of gemstones in Chanthaburi_14 Abstract: Corundum is divided into two main groups. The first group is rubies, which are red gemstones, and they extend to purple. The second group is sapphires, which are other colors. Blue sapphires are called pailin or  phailin, yellow is called butsarakham, green is called emerald. @chapter:3


Publication Year: 2002 Title: Summer 2002 G&G Lab Notes Abstract: Aurichalcite
Another Commercial U.S. Facility Offers HPHT Annealing for Diamonds
Challenges in Recognizing a Color Attribute’s Effect on Color Grading Fancy Colors
Diamond “Pearl” Necklace
Internal Laser Drilling Update
Unusual “Pink” Diamond
High-Quality Synthetic Jadeite from General Electric
Cobalt-“Diffused” Sapphire
Yellow-Green Schlossmacherite Beads

To view the full section, download the PDF above. @chapter:35


Publication Year: 1984 Title: Winter 1984 G&G Lab Notes Abstract: Unusual Diamond Inclusion
Natural and Imitation Emeralds
Oolitic Opal
Dyed Cultured Pearls
First American Freshwater Cultured Pearls from Tennessee
Pseudo Star Quartz
Ruby Simulants
Spinel and Synthetic Ruby Doublet
Heat-treated Sapphire Colors
Color Change Spinel
Treated Tourmaline

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


Publication Year: 2022 Title: Cuprite and Malachite in Agate from the Yanyuan Region, Sichuan Abstract: Figure 1. This 9.40 g gray-purple pendant was identified as agate. Photo by Su Xu.
The Yanyuan region in China’s Sichuan Province is rich in agates known for their vibrant colors, including pink, purple, and green. Dendritic inclusions are common in agates from many areas but rarely seen in agates from Yanyuan. Recently, our interest was drawn to a 9.40 g gray-purple carved pendant submitted for identification (figure 1) that displayed peculiar dendritic inclusions. The piece was reported by the client to be from Yanyuan.
Standard gemological testing of the pendant yielded a spot refractive index of 1.54, and Fourier-transform infrared (FTIR) spectroscopy was used to confirm the identity of the pendant. Microscopic observation revealed a blue-green spherical mineral surrounded by copper-red dendritic inclusions (figure 2), which appeared to have a metallic luster under reflected light.

Figure 2. Microscopic observation of the pendant revealed copper-red dendritic inclusions and a blue-green spherical inclusion. Photomicrograph by Su Xu; field of view 1.5 mm.
The red inclusions in the exposed surface and the blue-green inclusion nearby were analyzed with Raman spectroscopy. The analyses showed that the red inclusions were cuprite (Cu2O) and the blue-green sphere was malachite (Cu2(CO3)OH2), both of which were confirmed by energy-dispersive X-ray fluorescence (EDXRF) testing (figure 3). In the Raman spectra of the inclusions, the peak at 464 cm–1 was assigned to the agate host (figure 3).

Figure 3. Comparison between the Raman spectra obtained for the two kinds of inclusions found in the agate and reference spectra for cuprite and malachite from the RRUFF database. Spectra are offset for clarity.
While copper inclusions have been previously reported in purple chalcedony (Spring 2019 G&G Micro-World, p. 111) and chrysocolla chalcedony (M. Ye and A.H. Shen, “Gemmological and mineralogical characteristics of chrysocolla chalcedony from Taiwan, Indonesia and the USA, and their separation,” Journal of Gemmology, Vol. 37, No. 3, 2020, pp. 262–280), this is the first time we have identified two kinds of copper-bearing inclusions in agate from Yanyuan. @chapter:5


Publication Year: 2023 Title: Musical Diamond Abstract: A crystal with a stress halo and a smaller adjacent crystal resembles a dotted quarter note. Several reflections of such crystals with stress fractures are visible. Photomicrograph by Michaela Damba; field of view 2.90 mm.
Recently the author examined a 0.95 ct diamond with a special note. It only took one and a half beats to discover a dark crystal with a straight stress cleavage crack shaped like a dotted quarter note (see above).
Crystals, cleavages, and other inclusions are common occurrences that impact a diamond’s clarity grade. This diamond received a clarity grade of SI1, or slightly included with inclusions noticeable to a skilled grader at 10× magnification. @chapter:31


Publication Year: 2010 Title: Gem Localities of the 2000s Abstract: While the past decade saw some impressive discoveries of diamonds and colored stones (such as corundum, spinel, garnet, and tourmaline), it also witnessed reduced gem production in many areas as a result of high development costs, environmental considerations, and the downturn in the global economy. With legal and ethical restrictions on the trade in gems from some nations, and with premium market values paid for certain stones from particular sources, “locality of origin” determinations took on increased importance for some colored stones such as ruby, sapphire, emerald, and copper-bearing tourmaline. This article reviews the geographic sources of diamonds and colored stones, as well as the areas of production for both natural and cultured pearls, that were commercially important during the years 2001–2010. Maps of most of the important gem-producing regions of the world are included on an accompanying wall chart.

	DATA DEPOSITORY

Diamond Localities
Diamond and Colored Stone Localities, by Country
Localities of Minor Colored Stones
Complete Reference List for Text and Tables
Complete Listing of Acknowledgments
Pearl Localities, by Location and Mollusk
	August 15, 2010 @chapter:7