Ruby and Sapphire Markets Transformed

The following report is published courtesy of Diamond World

Adapted by Russell Shor, GIA senior industry analyst

The Gemological Institute of America has furnished an article on the progressive changes observed in the adaptation of rubies and sapphires into the gem and jewelry industry, as follows:

Ruby and sapphire are among history’s most coveted gems, with fashioned stones dating back to ancient Greece, India, and Asia. Traditionally, they have been scarce and expensive. The past 25 years, however, have brought radical changes in the market for rubies and sapphires, stimulated by huge increases in supply. Today, they are much more readily available in a full range of prices. This is because of the discovery of large deposits around the globe and the development of treatments that could consistently transform unattractive material into beautifully colored gems. By 2009, ruby and sapphire accounted for about one-third of all colored stone and pearl sales worldwide.

The lead article in the Winter 2009 issue of Gems & Gemology, Russell Shor and Robert Weldon’s “Ruby and Sapphire Production and Distribution: A Quarter Century of Change,” chronicles these new sources and treatment methods and how they coincided with new sales outlets, such as television and online shopping. It also examines how corundum supplies and prices have been buffeted in recent years by political events and social concerns.

Myanmar (formerly Burma) has been at the center of the ruby story for centuries. The ancient Mogok deposits, the traditional source of the world’s finest material, have continued to produce, while a new discovery, Mong Hsu, began to yield large quantities of commercial material during the mid-1990s. By the early 2000s, the country was supplying an estimated 90 percent of the world’s rubies.

Other sources—Kenya, Vietnam, and Madagascar—also began to supply the market, and ruby became fairly plentiful during the 1990s and early 2000s. Most recently, in 2007, fine stones began to emerge from a new locality in Winza, Tanzania. Prices for medium- and commercial-quality material eased considerably, and with larger supplies available at attractive prices, designers began to turn out lines of mass-market ruby jewelry.

Changes in the sapphire market have been even more profound. While traditional sources such as Kashmir, Thailand, and Cambodia were becoming mined out, new production from Sri Lanka, Australia, Madagascar, and (briefly) the U.S. state of Montana poured into the market.

In earlier times, much of this material would not have been mined because it was either too pale (Sri Lanka) or too dark (Australia), or had a less-commercial color (Madagascar). But gem dealers, primarily in Thailand, perfected heat-treatment processes that could consistently improve the colors of these goods. Thus, millions of carats of previously unusable sapphire were transformed into attractive gems.

The treatments, while a boon to the gem market, were also controversial, primarily because many dealers failed to disclose them to buyers. In time, the trade generally accepted straight heat treatment—subjecting ruby and sapphire to high temperatures under controlled atmospheric conditions. But in 2001, treaters took that process one step further, creating a furor that resounds today.

That year, an abundance of pinkish orange “padparadscha” sapphires entered the market. Because such sapphires are normally quite rare, the sheer quantity of these stones prompted gemologists and dealers to suspect a new form of treatment. Eventually they discovered that beryllium was being diffused into the stone during the heating process, radically altering the perceived color. Beryllium diffusion was subsequently used to modify blue and other colors of sapphire, as well as ruby, expanding the controversy and attracting a spate of negative press reports.

Also impacting the market were the large quantities of attractive ruby that began to show up in the early 2000s. Much of the material, it was quickly discovered, had been filled with lead glass to conceal abundant fissures in cloudy pink sapphires that were otherwise unsuitable for gem use. Fortunately, this treated material is easily identified with magnification.

International politics also affected the ruby and sapphire trade. To censure Myanmar for human rights abuses, the U.S. Congress enacted the Burmese Freedom and Democracy Act in 2003, which banned trade in gems and other products from that country. But the ban left a huge loophole that allowed the import of gemstones if they had been cut in a third country. The vast majority of Burmese gems were cut in neighboring Thailand, so the ban had little real effect.

As repression in Myanmar increased, however, the European Union enacted its own ban on Burmese gems, followed in 2008 by a tightening of the U.S. measure that effectively banned all Burmese ruby and jadeite imports regardless of where they were cut. As a result, more than 50 ruby mines closed down in Myanmar, while buying by foreign dealers reportedly fell by more than half in the latter part of 2008.

The need to identify which rubies were Burmese highlighted another issue: country of origin. Colored stones from certain localities, such as Mogok ruby and Kashmir sapphire, have traditionally commanded the highest premiums. Although many feel that gemstones should be judged by individual beauty rather than source, recent technological advances have given laboratories the tools needed to make more accurate country-of-origin determinations.

As Burmese rubies were being removed from the market, Madagascar, the world’s largest sapphire producer in the mid-2000s, abruptly banned export of all rough gem materials in early 2008. A Thai delegation visited the country to negotiate an end to the embargo, but failed to secure an agreement. The ban was lifted in mid-2009 after a coup toppled the president. By then, however, the number of miners working the vast Ilakaka sapphire deposits had shrunk to one-fourth its peak.

Despite these challenges, demand for ruby and sapphire grew strongly during the 1990s and into the 21st century. One 2009 study reported that they accounted for almost one-third of the $10.3 billion worldwide retail market for colored stones and pearls. A second 2009 study, by mining company True North Gems, broke the numbers down further: ruby accounted for $2.1 billion, sapphire $800 million (with $58 million of that pink sapphire). Note that sales figures for sapphire are lower because of the vast quantities of inexpensive lesser-quality and diffusion-treated material in the market. By comparison, emerald sales totaled $1.4 billion.

Looking to the future, the colored stone trade is moving to address growing consumer demand for fair trade goods that meet standards of safe working conditions, fair economic returns to miners and their communities, and environmentally sustainable practices. A number of industry organizations are working with mining operations and gem dealers to hasten progress toward these goals.

The future of the corundum market depends on finding new, economic ruby and sapphire deposits. But the trade’s understanding of treatments and willingness to disclose them will grow ever more important in maintaining consumer confidence, as will awareness of consumers’ desire to own beautiful products that embody positive social, ethical, and environmental values.

Courtesy: GIA

Green Beryllium-Diffused Sapphire

The following article is published courtesy of Gemological Instute of America’s Gems & Gemology’s eBrief

Author: Nathan Renfro

Image courtesy of: Gemological Institute of America

All Rights Reserved

Chemical analysis revealed that this 14.20 ct green sapphire was treated by beryllium diffusion. Photo by Robison McMurtry.

Be-diffusion of corundum has become somewhat common in the gem trade, and has been applied to produce a wide range of colors. In fact, the Carlsbad laboratory routinely encounters blue, yellow, orange, pink, and red examples. Green is one of the more unusual colors for this material, especially in larger sizes, but we recently examined a 14.20 ct sample that was beryllium diffused.
 
The standard gemological properties were consistent with corundum. Microscopic examination revealed particulate clouds, flux-healed “fingerprints,” discoid-like fractures, and planar growth features. The desk-model spectroscope showed strong iron-related absorption centered at 450 nm. As expected, immersion displayed alternating blue and yellow color zones, a common feature in green sapphires.
 
The GIA Laboratory uses LA-ICP-MS to test all heat-treated corundum for the presence of beryllium. Since this stone showed features consistent with heat treatment, it was analyzed. We found it to contain an average Be concentration of just over 13 ppmw (27 ppma), enough to dramatically alter the color.
 
When beryllium diffusion was first detected in the early 2000s, the orangy pink to pinkish orange sapphires were recognizable by their surface-conformal color zoning. The vast majority of Be-diffused corundum now being processed, however, does not show this type of zoning because the stones are diffused all the way through. Microscopic evidence of high-temperature treatment can raise suspicion of Be diffusion, but only chemical analysis by a technique capable of detecting traces of Be can confirm the treatment.
 
Nathan Renfro
GIA Laboratory, Carlsbad

 

Sinkankas Symposium Showcases Feldspar, from Ordinary to Extraordinary

The following article appears courtesy of Gems & Gemology‘s eBrief

All rights and Intellectual Property belong to Gemological Institute of America

A group of four labradorite feldspars from GIA’s Edward J. Gübelin Collection: a 30.82 ct cabochon from Finland; a 3.53 ct bicolored green and orange oval cut from Oregon; a 2.60 ct deep orange oval cut from Oregon; and a 4.18 ct light orange oval cut from Oregon. Photos by Robert Weldon.

What do false teeth and moonstones have in common? Or dinner plates and sunstone? How about roofing materials and labradorite? Scouring powder and amazonite?
 
They’re all made from the most abundant mineral group on Earth: feldspar. We walk on it, eat off it, clean with it and, yes, wear it as jewelry.
 
“Feldspars are absolutely everywhere,” said GIA photojournalist Robert Weldon as he introduced the featured gemstone at the eighth annual John Sinkankas Symposium in April. “The Earth’s crust is comprised of between 50 to 60 percent feldspar.”
 
The Sinkankas Symposium, co-hosted by the San Diego Mineral and Gem Society and GIA, was created by Roger Merk to honor the memory of legendary gemologist John Sinkankas, who called feldspar “one of the most fascinating gems known to man.”
 
A silicate mineral made up of silicon, oxygen and aluminum and influenced by other elements, feldspar displays the most gem phenomena of any group, including schiller, labradorescence, peristerescence, cat’s eye and adularescence. That’s what makes them so interesting, Weldon said.
 
“True gem feldspars are few and far between – most of it is just rock,” said GIA researcher John Koivula during his presentation on the microworld of gem feldspars. Most of the time feldspar is merely the matrix holding the gem specimen, which might seem unimportant. “But it can tell you something about the geology and chemistry of the environment that produced the stone,” Koivula said.
 
Also, Dr. Skip Simmons, a researcher at the University of New Orleans, reviewed feldspar’s mineralogy, chemistry and crystallography and talked about his visit to a gem orthoclase deposit in Madagascar. 
 
Lisbet Thorenson, an author and consultant from Beverly Hills who studies ancient gems, described the archaeogemology of amazonite and recent surveys of ancient Libyan and Egyptian mining sites by co-author and geologist Dr. James A. Harrell (University of Toledo).
 
Si Frazier, an author and collector of minerals and gems from Cerritos, California, recounted his trip to Finland in search of spectrolite, which he called “the most beautiful laboradite feldspar type I’ve seen.”
 
Meg Barry, a gem cutter from Fallbrook, California, described feldspar as the “Volkswagen of gemstones – there’s a lot of it, it’s affordable and everyone can have one.” While it may not at first appear to be an exciting stone, she said, it can be cut to be exciting. Berry showed examples of pieces she had recently cut, documenting each step from the beginning rough to the final cut and polished stones.
 
Noted mineral collector Rock Currier, owner of Jewel Tunnel Imports in Baldwin Park, California, related his travels seeking amazonite in Colorado and Ethiopia.
 
Bill Larson, a collector from Pala, California, who travels the world in search of the finest gemstone specimens, shared images of world-class feldspars from Myanmar to Madagascar.
 
Shane McClure, director of identification at GIA’s Carlsbad laboratory, and Dr. George Rossman of the California Institute of Technology in Pasadena addressed the controversy surrounding natural versus treated andesine.
 
“Treatment of feldspar never used to be a serious problem,” McClure said. “But, as has happened with so many gem materials over the past couple of decades, that changed several years ago when gem-quality andesine entered the market.”
 
Researchers began to investigate red and green andesine from China to determine if its color was natural or had been treated, comparing its geologic, chemical and gemological characteristics to known natural labradorite from Oregon and Mexico and untreated yellow andesine from Mongolia.
 
They found that the composition of Tibetan andesine, particularly its anorthite content, overlaps with Mongolian material, but not Mexican or Oregon labradorite. There are no obvious differences in the internal features of Mongolian, Mexican and Oregon material, except for larger copper platelets and potential differences in color zoning seen in some untreated Oregon stones. Material from all three locations has overlapping UV fluorescence. 
 
“Gemologically speaking, the material is very interesting,” McClure said, but GIA knows of no way to reliably separate Tibetan from treated Mongolian stones.  Oregon and Mexican stones can easily be separated from the Chinese using chemistry or sometimes refractive index.
 

Rossman concluded the presentations with evidence that feldspar’s color can be changed through the diffusion of copper. All the samples of red and green feldspar he had analyzed, said to be from Asia and the Congo, were treated by copper diffusion.

 
To learn more about red feldspar, see News from Research.

From Gems & Gemology: CVD-Grown Diamonds that Change Color with Heat or UV Exposure

The following article appears courtesy of GIA’s Gems & Gemology eBrief

All rights and intellectual property belong to GIA

Synthetic diamonds grown by chemical vapor deposition (CVD) have seen significant advances over the last decade, reaching the mainstream jewelry market in larger sizes and better qualities. Meanwhile, new processes have dramatically improved the color of these products.
 
But an article in the new Spring 2010 issue of Gems & Gemology shows that some CVD synthetics undergo temporary color changes in response to UV radiation or heat. In the study, De Beers DTC researcher Dr. Rizwan Khan and coauthors examined a group of untreated Element Six lab-grown diamonds. The samples became darker (from Fancy to Fancy Deep brown in one case) when exposed to UV radiation, a routine part of gemological testing. Heating them to 450°C, a temperature exceeded in some jewelry repair procedures, lightened the color (from J to E in another case).
 
“Although the CVD-grown diamonds did revert to their stable color over time when exposed to light, the color alterations could have important implications for grading if the gems were placed in the dark immediately after the exposure,” said Alice Keller, editor-in-chief of G&G. 
 
In another major article from the Spring issue, Dr. Wuyi Wang and coauthors look at a new generation of strongly colored pink CVD synthetics from Boston-based Apollo Diamond Inc. The study describes the characteristics of these Fancy Intense to Fancy Deep pink lab-grown stones, as well as the gemological and spectroscopic criteria for identifying them.
 
The Spring issue also includes articles on the possible existence of “sister” stones of the Hope diamond, the use of confocal micro-Raman spectroscopy to identify natural and synthetic emeralds (and emeralds from specific localities), and rare brownish orange bastnäsite-(Ce) and parisite-(Ce) from Malawi.
 
The G&G Lab Notes section features the latest discoveries from the GIA Laboratory, including natural pink diamonds colored by multiple treatment processes, a large HPHT-treated type IIb blue diamond, and unusually transparent treated jadeite. The Gem News International section covers the 2010 Tucson gem shows, including “soufflé” freshwater cultured pearls, and reports on tsavorite mining in northern Tanzania and treated-color pink CVD-grown synthetic diamond melee.
 
Two special Spring issue features are this year’s Dr. Edward J. Gübelin Most Valuable Article Award winners and the G&G Challenge, a multiple-choice quiz based on articles from the 2009 issues. Subscribers who score 75 percent or better on the G&G Challenge receive a GIA Letter of Completion; those who score 100 percent also get recognition in an upcoming issue.
 

Copies of the Spring 2010 issue (print and PDF) can be ordered from the GIA Store. To purchase PDF versions of specific articles or sections, visit Gems & Gemology Online. To subscribe to G&G, visit the GIA Store or contact Circulation Coordinator Martha Rivera at martha.rivera@gia.edu or call toll-free (800) 421-7250, ext. 7142. From outside the U.S. and Canada, call (760) 603-4000, ext. 7142. 

Industry Analysis: Protests Halt Thai Gem Trade

The following analysis is published courtesy of GIA’s Gems & Gemology eBrief

Intellectual property and all rights belong to Gemological Institute of America

Author: Russell Shor

Thailand’s gemstone industry has come to a near standstill in Bangkok, as battles between government forces and “Red Shirt” protestors shut down much of the city. More than 40 protestors have died in the violence that has gripped the country for nearly six weeks. The protestors, many demanding the resignation of Prime Minister Abhisit Vejjajiva, periodically blocked major arteries in a series of skirmishes with troops, until the government’s full-force response began late last week. The clashes began to subside yesterday. While the violence did not spill over to Chanthaburi, the city where most of the country’s colored stone industry is headquartered, it has badly damaged several major shopping malls and forced the closure of many sales offices in Bangkok’s business district . The GIA Laboratory Bangkok and the GIA Thailand campus also closed for most of this week. The airport remains open, but passenger count is down by two-thirds, according to press reports. Some of the country’s industry leaders have issued dire warnings about the state of Thai business if an agreement is not reached soon. Dusit Nontanakorn, chairman of the Thai Chamber of Commerce, said prolonged demonstrations, particularly in Bangkok’s main shopping and business area, could bring about a collapse of the overall economy. Even if the protests end now, he said, the government still has a lot of hard work ahead, including stimulus efforts and reducing income disparity. “Everybody in the entire social structure must team up together to get out of this trouble, before the destruction of the entire country.” Thailand’s colored stone exports totaled $139 million for the first quarter of 2010. Exports of diamonds for the same period totaled $297 million, with finished jewelry at $742 million. In neighboring Myanmar, the government reported earnings of $504 million from its March sale of jade, gems and pearls. It plans another sale next month. The Myanmar Central Statistics Agency also reported official sales of 32,921 tons of jadeite, plus 18.7 million carats of colored gemstones and 201,081 momme (754 kg) of cultured pearls. AUCTIONS: Demand and prices for top diamonds (which all carried GIA reports) remained strong at the major auction houses. At Sotheby’s May 11 Geneva sale, a 7.64 ct Fancy Intense blue diamond drew a winning bid of $8 million, just under $1.1 million per carat, nearly 50% above the pre-sale estimate. At the same sale, a 52.82 ct D-Flawless type IIa square-cut diamond brought $7.93 million, more than $150,000 per carat. A ring containing two pear-shaped diamonds — a 5.02 ct Fancy Vivid blue and a 5.42 ct D-Flawless — brought $6.3 million. The following day at Christie’s Geneva, a private buyer paid $127,000 per carat for a 40.21 ct D-Flawless diamond, while a Swiss retailer paid $162,000 per carat for a 16.92 ct D-Flawless round brilliant. MACRO: The U.S. retail sector continues its slow recovery from last year’s depths. The U.S. Department of Commerce reported that April sales increased 4.6% over the previous year and 0.5% over the previous month. Meanwhile, the National Retail Federation reported that retail sales were up 5.6% for March and April, compared to the same period last year. In Japan, sales of diamonds and jewelry continued their three-year slide, declining 1.8% in April against the same month in 2009, according to the nation’s Department Stores Association. The group noted, however, that demand for high-ticket items began to pick up during the month as wealthy consumers ventured back into the market.

Russell Shor

Senior Industry Analyst

Lab Identifies First CVD Synthetic Diamond Over One Carat

The following alert is published courtesy of Gems & Gemology G&G eBrief, the electronic newsletter by Gems & Gemology

All rights reserved. Intellectual Property: Gemological Institute of America

Latest-Generation CVD-Grown Synthetic Diamonds from Apollo Diamond Inc.; image courtesy of GIA

Single-crystal CVD* synthetic diamonds are occasionally submitted to the GIA Laboratory for identification and grading reports. For the first time, the New York lab has identified a near-colorless CVD-grown diamond larger than a carat that was submitted for grading.
 
This 1.05 ct pear shape (9.81 x 5.95 x 3.06 mm) was color-graded as equivalent to G. In addition to pinpoint inclusions, it contained some feathers and fractures along the girdle, and its clarity grade was equivalent to I1. No fluorescence was observed when it was exposed to conventional long- and short-wave UV radiation. The infrared absorption spectrum indicated that the sample was type IIa. Images taken with the DiamondView, which employs strong ultra short-wave UV radiation, showed strong orange-red fluorescence with some irregularly shaped regions of blue fluorescence. Photoluminescence spectra collected at liquid-nitrogen temperature with laser excitations from the UV to IR regions revealed features typical of a CVD synthetic diamond, and this identification is consistent with its other properties.
 
Clearly, CVD synthetic diamonds of better quality and size are being produced as the growth techniques continue to improve.

Wuyi Wang and Kyaw Soe Moe
GIA Laboratory, New York
 

* CVD stands for Chemical Vapor Deposition, a chemical process used to produce high-purity, high-performance solid materials. The growth occurs under low pressure (below atmospheric pressure). It involves feeding a mixture of gases (typically 1 to 99 methane to hydrogen) into a chamber and splitting them to chemically active radicals in a plasma ignited by microwaves, hot filament, arc discharge, welding torch or laser. This method is mostly used for coatings, but can also produce single crystals several millimeters in size (see picture).

You can get further general information about CVD on Wikipedia. Another interesting article about CVD diamonds identification has been recently published by GAAJ. (ndr)

Basel and Hong Kong: High-End Stones Pace Market

The following article appears courtesy of GIA Gems & Gemology eBrief

Intellectual Property: Gemological Institute of America

Photo by: Robert Weldon

Author: Russell Shor

Fine rubies from outside Myanmar, such as this 14.97 ct ruby from Winza, Tanzania, continue to command top prices in the market. Courtesy Mona Lee Nesseth Custom and Estate Jewels and a private collector; photo by Robert Weldon.

Diamond demand at the recently concluded BaselWorld and Hong Kong Watch and Jewellery fairs was concentrated in the high end, with stones of more than 5 ct bringing strong prices. While a significant portion of buyers were from Asia, demand was also strong from the U.S. and Europe.
 
Dealers reported a perceived shortage of such goods, particularly because rough diamond production remains well below the peak levels seen before the 2008-09 economic crisis. The continued weakness of the U.S. dollar – the trading currency for diamonds – against other major currencies is also contributing to higher prices.
 
Prices for top rubies were also very strong because of extreme shortages of supply. The ban on Myanmar goods in the U.S. and European Union is keeping most of the best stones off the market, and dealers are holding on to top rubies from other localities in hopes that a full economic recovery will bring even stronger prices.
 
The major auction houses are moving to take full advantage of these trends, packing important stones into upcoming sales in Hong Kong, New York, and Geneva.
 
Russell Shor
Senior Industry Analyst, GIA Carlsbad

From Gems & Gemology: First Report of Cat’s-Eye Rhodonite

This article is published courtesy of  Gemological Institute of America‘s Gems & Gemology
Author: Brendan Laurs
Intellectual property: GIA
Photo by: Robert Weldon 
 

This cat’s-eye rhodonite (6.93 ct) from Brazil shows good chatoyancy. Photo by Robert Weldon.

Gems & Gemology editor Brendan Laurs prepared the following entry for the G&G Gem News International section.  

Rhodonite (MnSiO3) is an attractive pink-to-red mineral that is often sold as specimens or ornamental material, but seldom as a gemstone, since it is typically opaque and has perfect cleavage in two directions. Facetable material is very rare, and small amounts are occasionally produced from just two localities — Broken Hill, Australia, and Minas Gerais, Brazil. Some polished material has a saturated color that resembles fine spinel or rhodochrosite.

 At last month’s Gem & Jewelry Exchange show in Tucson, Luciana Barbosa (Gemological Center, Belo Horizonte, Brazil) had some attractive rhodonite cabochons showing good chatoyancy (e.g., see figure). She reported that the material was found in 2009 at Morro da Mina, near Conselheiro Lafaiete in Minas Gerais. The rhodonite is recovered as a byproduct of manganese mining, in a large open pit operated by Companhia Vale do Rio Doce. Barbosa knew of about 30 pieces of the cat’s-eye rhodonite (ranging from approximately 2 to 40 ct), and she had not seen the material previously. To her knowledge, the stones were all untreated. She indicated that the identity of the rhodonite was confirmed with X-ray diffraction analysis.
 
We believe this is the first report of cat’s-eye rhodonite.
 
For the latest gemological developments around the world, read the Gem News International section in every issue of G&G. PDF copies of the journal are available at Gems & Gemology Online. To purchase a print copy or to subscribe to G&G, visit the G&G order page or contact Circulation Coordinator Martha Rivera by calling toll-free (800) 421-7250, ext. 7142. From outside the U.S. and Canada, call (760) 603-4000, ext. 7142.