Recent research by Christopher P. Smith and the team at American Gemological Laboratories (AGL) regarding heated sapphires with unstable color centers has been published in The Journal of Gemmology, Volume 36, No 7, pp 602-604. See below for the article!
AGL attended the preview last week for Christie’s breathtaking auction, Maharajas & Mughal Magnificence. We were privileged to be able to work on some of the lots here at the lab! Check it out!
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The AGL team was honored to attend the preview of the Maharajas & Mughal Magnificence last week. We were privileged to test a number of items from this unparalleled collection. Here are just a few of the lots that came through the lab. * * * #gems #gemology #gemstones #gemologist #gemlab #agl #coloredstones #preciousstones #preciousjewels #finejewelry #christiesjewels #indianjewels #maharajasandmughalmagnificence
For a primer on some of the rarer gemstones out there, check out the “The Most Unusual Gems You’ve Never Heard Of” published in the New York Times on May 11, 2019. Christopher Smith, the president of AGL, lends his expertise and knowledge to help understand what makes some gems such as Red Beryl, Diaspore, Benitoite, Grandidierite and others extra special.
To read the article, visit — https://www.nytimes.com/2019/05/11/fashion/jewelry-rare-gems-tanzanite.html
Below is an example of a Prestige Report with the above mentioned modifications noted in red.
Dear Clients, Colleagues and Industry Friends,
This coming Monday, we will celebrate American Gemological Laboratories’ 10 year anniversary. It was the 1st of April 2009, a difficult period in our industry, when I took over the reins of AGL. At the time, we were a team of six. We are now a team of thirteen. It is a matter of great pride to see the company growing, embracing a good value system and achieving more than we had ever thought possible. To our present and former employees, who have worked to pave the way to our success, I say a heartfelt "thank you". I take pride in saying that AGL employs exceptional women and men who all have integrity, intelligence, high aspirations and dreams - both personally and professionally.
When I acquired the lab, my first task was to paint a picture for the future of the business. It was important that as a small family-owned company we maintained transparency and approachability. We pride ourselves in our service to the industry and our availability to clients. We always do our best to deliver personalized client service care. This includes being on a first name basis with most of our clients, developing relationships and taking the time to explain results in detail. We also truly enjoy meeting you at trade shows, letting us put a face to the name.
Over the past decade, AGL has also expanded the scope of our services, breaking ground in the international marketplace. To be in the company of other internationally renowned gemological organizations is an honor in itself. As a gemological laboratory, we strive to set the highest bar possible in gemstone reporting and continuously aim to be on the cutting edge of innovations, new technology and gemstone knowledge.
This milestone is not just for those who have been a member of the team but also a celebration for everyone who has supported AGL in the last ten years. Whether you are an old client or a new one, we appreciate your support all the same. I thank you for standing by us in this ever-changing industry. It is a privilege to work with all of you and for all of the outstanding gems and jewels which we are fortunate enough to see. As we enter our next chapter, the AGL team looks forward to continue building upon our principle of providing top-quality service to our clients and fostering new relationships throughout our industry.
Thank you all for being part of AGL’s success over the past 10 years.
We look forward to the next 10 and can’t wait to see what the future brings!
Christopher P. Smith, President
American Gemological Laboratories LLC
Modifications to Prestige report formats
NEW YORK: 28 November 2016 ― Following changes instituted during the development of a new wholly integrated computer system, American Gemological Laboratories (AGL) has modified some of the features present on its Prestige level full-page reports.
Enhancements Section: An integral part of every AGL Prestige report is the section that discloses the presence or absence of possible treatments. In 2009, AGL took an innovative approach towards addressing gemstone treatments by separating them into Standard and Additional enhancements. This was done to help clarify that some treatments are commonplace for certain varieties, while others are not, as well as to the compound nature of gemstone treatments today.
Further, there were three additional elements that addressed A) Degree, B) Type and C) Stability of the treatment, if present. Previously, when there was no treatment present or any of these three elements were not relevant to a particular treatment, a distinction of ‘N/A’ (not applicable) was placed next to the appropriate area. See examples of AGL reports prior to 28 November 2016.
Going forward, these additional elements of Degree, Type and Stability will only be present on a report when associated with a particular treatment. No longer will there be a need for the ‘N/A’ designation to be used. See examples of AGL starting as of 28 November 2016.
Examples prior to 28 November 2016:
Examples as of 28 November 2016:
“This change being made is based on comments from our clients,” indicated Christopher P. Smith, President of AGL. “They have expressed that it was on occasion confusing for their customers when they read the N/A or Not Applicable statements on our reports, so we expect that this change will make our reports clearer.”
Provenance Section: For certain gem varieties, the AGL also offers the service to determine a gem’s country-of-origin. For stones submitted for an origin determination, if two essential criterions were met, then an additional label of AGL Classic™ was added to the origin (e.g. AGL Classic™ Colombia). These conditions are:
The origin determination is of a high confidence level
A gemstone exhibiting the kind of superior quality that helped to earn a particular source its name and reputation in the industry.
Prior to 28 November 2016, the term AGL Classic™ was only applied to select and more historical sources of a given gem variety, such as Burma (Myanmar), Ceylon (Sri Lanka) and Kashmir for sapphires and Colombia for emeralds and so on. This term was not utilized for all possible origins.
Going forward, the term AGL Classic™ may be applied to any source or origin for any gem variety where a country-of-origin determination may be requested, if the following conditions exist:
The origin determination is of a high confidence level
When the quality of a given gemstone is top gem-quality.
“The label of AGL Classic™ is used to distinguish a top, top gem.” Smith indicated. “Such superior-quality gems have the potential to come from any of the world’s gem sources, so we have made this change to acknowledge that it is not only the historical sources that are worthy of the AGL Classic™ designation.”
About American Gemological Laboratories
American Gemological Laboratories (AGL) is the United States’ most widely known and respected colored stone gem identification and quality-grading laboratory. It was founded in 1977 and became the first gemological laboratory in the US to provide quality grading as well as country-of-origin determinations for colored stones. AGL has become an iconic brand for uncompromised standards and excellence in gemstone reporting (www.aglgemlab.com).
Christopher P. Smith
Ruby Treatments: From Oiling to Diffusion…
And Everything In Between
Date: Friday February 5, 2016
Place: Tucson Convention Center, Mohave Room
Please Note: If you want to attend the hands-on lab session afterwards, you must be one of the first 30 people in line. We recommend arriving early. We look forward to see in you there!
American Gemological Laboratories (AGL)
What the retailer and appraiser need to know to recognize these gems and their proper disclosure
Abstract: In today’s market, ruby remains one of the most popular gems sold at the wholesale and retail level. Yet never more than now have such a breadth of various treatments existed in the marketplace for this revered gem. Unaltered versions of these gems are available, but the majority of rubies sold in the US and abroad have undergone some form of enhancement or treatment. These range from simple or rudimentary forms of enhancement that are easy to detect, to the very sophisticated, requiring advanced analytical techniques to identify. This lecture and workshop will review natural ruby available in the market today - both untreated and the various forms of treated. It will also include lead-glass treated, otherwise known as Composite Ruby. Guidelines for how the average gemologist may recognize these various ruby treatments will be provided. In addition, the first 30 attendees will have the opportunity to examine a number of examples.
Dear Friends of AGL,
We are delighted to announce that Christopher Smith and American Gemological Laboratories are being honored with the “Excellence in Gemology Award” by the Indian Diamond & Colorstone Association (IDCA). See below.
You do not need to be a member to attend the event and/or submit a congratulatory advertisement to be included in the IDCA Annual Gala Awards Night program. Please see the attached document for instructions.
American Gemological Laboratories (AGL)
Sub: IDCA’s Prestigious Annual Tucson Gala
February 4th, 2016 - AGTA Gem Fair
We take great pleasure to inform you that IDCA’s signature 32nd Annual Tucson Gala will be held on Thursday, February 4th, 2016 during the AGTA Gem Show at the Marriott University Park Hotel in Tucson.
The Indian Diamond & Colorstone Association, New York, has a long tradition of honoring key industry persons and organizations that have made a meaningful contribution to the industry and social endeavors at our annual awards ceremonies in Tucson and Las Vegas.
American Gemological Laboratories is the recipient of the “Excellence in Gemology” Award at this year’s event. The award is in recognition of their exceptional services and upholding the integrity and ethics on gemstone identification in the industry.
Our event is well attended by key industry leaders, jewelers and manufacturers and we are very happy to extend an invitation to you and your colleagues to share in this celebration to honor American Gemological Laboratories and Mr. Christopher Smith.
Attached please find the information on the various sponsorship categories available for your convenience. Kindly note the deadline for submission of any artwork is January 21st, 2016. Please contact our office for any further information at firstname.lastname@example.org.
We look forward to welcoming you at our event.
With warm regards,
Ashok K. Sancheti
INDIAN DIAMOND & COLORSTONE
(A Not-For-Profit Organization)
56 West 45th Street, 5th Floor
New York, NY 10036.
Tel: (212) 921-4488 Fax: (212) 768-7935 Email: Office@idcany.org
FOR IMMEDIATE RELEASE
AGL celebrates 5 years under new management
2 April 2014: NEW YORK – American Gemological Laboratories (AGL) a provider of high-quality gemstone analyses and reporting (www.aglgemlab.com) today announced its 5-year anniversary under the stewardship of Christopher P. Smith.
During the 1st week of April in 2009, AGL was acquired by Mr. Smith after the company’s brief sojourn under the umbrella of Collector’s Universe, a NASDAQ-listed publicly traded company. AGL was originally founded by C.R. “Cap” Beesley in 1977.
“Five years ago AGL was reprivatized during one of the most difficult financial periods the US and world markets have experienced in recent decades. However AGL had a good reputation and we did not want to see this legacy fade away.” indicated Christopher P. Smith, President of AGL. “Since then, we have seen a tremendous amount of growth and expansion in the scope of our activities, raising the name and reputation of AGL even further. The industry seems to appreciate the attention to detail that AGL imparts in the results we give, the products we offer and the attentive, personal service we provide”.
Immediately after acquiring the lab, Smith decided to concentrate all of AGL’s efforts on strictly colored stone reporting services. AGL focused on developing and refining robust criterion to ensure high-quality, repeatable and consistent methodology to gemstone identification, treatment detection and country-of-origin challenges facing the gemstone and jewelry industry.
Shelly Sergent, curator of Somewhere in the RainbowTM collection stated “Chris Smith and the AGL staff are knowledgeable professionals, who uphold impeccable standards, integrity and ethics for the gemstone industry. We use AGL exclusively for any gems to be considered for our collection.” She further indicated “AGL delivers the most informative and visually appealing certification in the industry. From the conclusions they present to the photos they provide, we find these certificates to add value to the provenance of our gems.”
AGL offers a comprehensive product line for the identification, enhancement disclosure, country-of-origin and full grading analyses of colored stones, such as ruby, sapphire, emerald, spinel and many other gem varieties. AGL provides independent laboratory services to a broad domestic and international clientele across the gemstone and jewelry industry. Clients range from major retailers to auction houses, wholesalers, manufacturers and privates.
In addition to the staple of the AGL’s product line, the Prestige ReportTM, AGL offers a lower-cost alternative for the standard identification and enhancement disclosure of gemstone via its innovative GemBriefTM format. In addition AGL has developed its premium product, known as the JewelFolioTM: A beautifully illustrated and detailed book to represent gemstones of singular importance.
The base of AGL’s operation is located along Fifth Avenue in the heart of New York City’s diamond and jewelry district however the laboratory has initiated the expansion of its brand and services by performing regular on-site testing programs during major trade shows in locations such as Tucson (Arizona), Las Vega (Nevada) and Hong Kong as well as other important market centers in Bangkok (Thailand), Colombo (Sri Lanka) and Kuwait.
“These first five years have seen significant growth in the AGL services, as well as brand awareness in terms of reputation and recognition. Our team is highly capable and focused.” laboratory manager Maria Frances stated. “In the coming months and years AGL will be investing heavily in the laboratory’s infrastructure to better handle the increasing volume, research and services.”
As a concluding remark Smith added: “Through our commitment to strict standards, high-quality products and personalized service, the AGL team is proud of what we have been able to accomplish in just five short years and we are looking forward to a very bright future.”
Click on this link to view some notable highlights from AGL past 5 years
American Gemological Laboratories (AGL) is the United States’ most widely known and respected colored stone gem identification and quality grading laboratory. It was founded in 1977 and became the first gemological laboratory in the US to provide quality grading as well as country-of-origin determinations for colored stones. AGL has become an iconic brand for uncompromised standards and excellence in gemstone reporting and is regularly featured by the auction houses of Christie’s and Sotheby’s for important colored stones they are offering for sale.
Christopher P. Smith
Auction Houses and Famous Jewels: AGL is approached on a regular basis to perform testing on notable, unique and historic gems and jewelry articles. A couple of truly exceptional opportunities include:
- The Elizabeth Taylor jewels: Christies – December 2011
- The Atocha Gold and Emerald ornament: Sotheby’s – February 2013
- BARRON’S: A false promise – How a gem expert wound up with a fake, and what you can learn from her experience.
- FINANCIAL TIMES, 27 March 2014: Certification industry provides reassurance on coloured gems. Valuation game - The industry’s go-to players. An honorable mention as one of the colored stone and jewelry industry’s most important laboratories.
Christopher Smith Awards:
- Christopher P. Smith recognized as one of the gemstone and jewelry industry’s top 50 most influential persons
- Christopher P. Smith awarded an honorary FGA by the British Gemmological Association
- CIBJO, ICA, GILC, JVC, AGTA recognize the term “composite” for the use of disclosing the lead-glass treated rubies, a product otherwise known as Composite Ruby
Excursions to important gem-producing localities: As part of our continuing efforts to remain at the forefront of gemology, AGL travels to the world’s most important gem-producing regions. There is an endless pursuit to study new gem materials, gemstone treatments and gem deposits.
- Tanzania: The Merilani tanzanite deposits
- Mozambique: The Montepuez ruby deposits
- Zambia: The Kagem emerald deposit
- Burma: The Mogok valley
Presentations given at international conferences: AGL is regularly asked to participate in gemological conferences held around the world.
- Accredited Gemologist Association (AGA): Tucson and Las Vegas
- Gemological Institute of America (GIA): Symposium and various Alumni chapter locations
- Gemmological Association of Great Britain (Gem-A): London, England
- Scottish Gemmological Association (SGA): Edinburgh, Scotland
- National Gemstone Testing Center (NGTC): Beijing, China
- Canadian Gemmological Association (CGA): Toronto, Canada
- GemWorld conference: Chicago
- Christie’s: Hong Kong
- Sotheby’s: Hong Kong
New York, 5 September 2013: During the most recent CIBJO conference this past May, the colored stone commission came together to address the disclosure nomenclature to properly represent the heavily treated lead-glass rubies that have been entering the industry in large numbers since 2003.
When CIBJO issued its press release following its 2013 conference in Tel Aviv (9 May 2013 press release), the colored stone commission issued its disclosure guidelines for lead-glass treated rubies. In the release, it was explained that CIBJO would follow the guidelines set out by the Laboratory Manual Harmonization Committee (LMHC), as well as recognizing the use of the term composite to describe these stones.
In order to accommodate the second approach, the colored stone commission amended its definition for the term composite to allow it to be used to describe this product. At the time of the press release, most publications focused primarily on the CIBJO decision to follow the LMHC in disclosing this product, without much mention of their pivotal change allowing for the use of the term composite to also represent these stones.
"AGL has received many comments from the industry members who did not fully recognize the impact and importance of the CIBJO decision following the conference, as it pertains to the use of the word composite for describing these heavily treated stones." Stated Christopher P. Smith, President of American Gemological Laboratories (AGL).
The previous definition of the word composite in the CIBJO Blue Book did not permit this term to be used as a description for these stones.
"This was a significant ruling for the CIBJO Colored Stone committee to make, which required a revision in the by-laws of the definition for the term composite." indicated Smith. "It was not unexpected that the CIBJO ruling would follow the terminology proposed by the LMHC. However, they have also approved the use of the word composite for this product, which was pioneered by the AGL."
The AGL's contention was always that this material represented a composite of lead-glass and natural ruby/corundum. This treatment process being fundamentally different from the more traditional heating practices used to treat rubies and therefore needed to be disclosed in a manner that made this distinction clear. In addition there are special care conditions inherent to this product that require further disclosure.
In closing Smith stated "I was very pleased to learn of the CIBJO decision to allow for both methods of describing this material. I believe that the CIBJO umbrella has again demonstrated its key fundamentals towards helping to establish useful and practical approaches for the betterment of our industry."
Background: Beginning in 2003, the industry saw a new type of treated ruby product entering the market in vast numbers. This treatment process took very low quality, industrial grade ruby and in-fused it with a high lead-content glass. In some cases the resulting stones are more ruby than glass however in other cases there is more glass than ruby. In all cases though the extent of glass in these stones is significant and there are special care requirements, as the glass may be damaged by a variety of standard bench jeweler practices and even household products.
The LMHC approach involves a multi-tiered disclosure for this lead-glass treated material that is dependent upon the extent of treatment. Only the most extreme cases are classified as "a manufactured product".
The AGL approach collectively describes all of this material as Composite Ruby, a product requiring special care.
Additional trade organizations that also recognize the term composite to describe lead-glass treated ruby: American Gem Trade Association (AGTA), International Colored Gemstone Association (ICA), Gemstone Industry and Laboratory Committee (GILC), Jeweler's Vigilance Committee (JVC)
28 January 2013: NEW YORK – American Gemological Laboratories (AGL): Gemstone treatments are a regular issue which the gemstone trade has to contend with. In May 2012, AGL first learned of a new type of treated sapphire which was becoming available in the Bangkok market “This treatment was first described to me as a new type of lead-glass treated corundum where a blue colorant was also introduced.” indicated Christopher P. Smith, President of AGL.
In November and December of 2012, clients of the AGL contacted the lab indicating that such stones were starting to be encountered in the marketplace. Recently a couple of samples were sent to the AGL by Dr. Cigdem Lule of GemWorld International Inc. Although the stones appeared fairly transparent and had a convincing “blue sapphire” color, color concentrations were readily visible upon closer scrutiny even with the unaided eye and were obvious with magnification using a 10x loupe or microscope (figure 1 below).
“A chemical analysis readily showed a high concentration of lead in addition to the aluminum oxide of corundum, with trace elements of iron and gallium, while a visible spectrum revealed absorption bands associated with cobalt.” Smith stated (figure 2 below).
When compiling JCK’s first Power List, we kept circling back to the question: How do you define power?
We decided early on that this industry was too sprawling and diffuse for us to rank its most powerful people on a strictly numerical basis. So we opted to break down our rankings by sector (each list is numbered for ease of reading; we did not rank individuals in each category). Not everyone on our list racks up millions of dollars in sales or can make exhibitors snap to attention at trade shows. Some of them operate strictly behind the scenes. But all of them are innovators who are ensuring this tradition-bound business prospers in the 21st century.
Of the 50-plus people who made the cut, we chose to highlight 10 we thought deserved special attention because they likely fly beneath most people’s radars. But by our reckoning, all of them make up the industry’s powers-that-be.
The JCK Power List was compiled by the magazine’s editors in consultation with numerous outside experts. And yet we are well aware that the final tally does not include every notable person in the trade. We fully expect this to spark heated debate. (Lord knows there were some heated ones while putting it together.) We may have bruised an ego or two. But we feel confident that everyone on the list matters.
By “matter,” we mean: The members of our Power List wield influence. They are listened to. They make things happen. And this business would be significantly different without them. We never really came up with a precise definition of power. But perhaps that’s as good as any.
HONG KONG / NEW YORK: 29 September 2011 ― Ever since the lead-glass treatment of ruby/corundum hit the market nearly 10 years ago, there have been issues over how to describe and represent this material for the trade and laboratories alike. GemResearch Swisslab (GRS) and American Gemological Laboratories (AGL) have come together to begin harmonizing the description of these stones on their respective gemological reports. “We wanted to let the gemstone and jewelry industries know that GRS and AGL have begun working in a spirit of collaboration between our labs and we believe that the controversies surrounding how these stones are described on our reports is a perfect venue to demonstrate this,” indicated Dr. Adolf Peretti, President of GRS Laboratories.
“Increasingly over the past several years issues surrounding the clear representation and dis- closure of this material have come to the forefront around the world”, stated Christopher P. Smith, President of American Gemological Laboratories. “Both GRS and AGL believe that this treatment needs to be clearly distinguished on our reports from the more traditionally heated rubies that are available in the marketplace in order to avoid confusion between these two products.”
Since the lead-glass treatment of low-grade ruby/corundum began entering the market in 2003, literally hundreds of thousands of stones have been sold globally. Gemologists, gemological and trade associations, as well as laboratories around the world have extensively published, lectured and generally communicated how to recognize these stones and the inherent issues of durability that surround this treatment, as well as the need for proper disclosure.
In November 2007, AGL took a high-profile position by coining the name Composite Ruby to describe all lead-glass treated ruby/corundum, while in 2010 GRS started using the name Hybrid Ruby for the same purpose.
Several features make these stones readily recognizable by anyone with little training and a loupe or microscope. Internal characteristics such as contraction bubbles in the glass, a distinct bluish and orangey color flash and the golden to red body color of the lead-glass make these stones easy to identify without the use of a gemological laboratory or advanced analytical testing. In addition these stones are not durable. Lead-glass treated ruby/corundum may be strongly damaged by some ordinary household products and routine repair by a bench jeweler.
Industry groups have detected an increased supply of highly treated “Ruby” products in the marketplace. According to information gathered by various industry members, these lead glass filled red stones are being sold throughout the supply chain including in U.S. department stores, venues in the Caribbean and elsewhere. These treated red stones have significant fissures filled with relatively large quantities of Lead Glass. They are often being sold as “Natural Rubies” without proper disclosure and most importantly with NO information on the required special care to maintain the appearance of the product.
Be Advised: This product is unstable and requires special care to avoid major and irreversible damage
To protect the consumer and the integrity of our industry we call upon the all sellers of this Composite Lead Glass “Ruby” Product - loose or in jewelry - to make the proper disclosures with the utmost clarity.
Failure to do so can directly lead to loss of consumer confidence not just for the Ruby market, but for all gemstones, including diamonds and jewelry. Additionally, it can result in potential legal action against merchants who fail to make the required FTC disclosures. Certain actions (heat or acid) that take place during repair or even normal wear can, and probably will, alter the appearance of these products, and render the jewelry unusable. Certain every day, common exposures to heat, acids and polishing can and probably will significantly alter the appearance and quality of these stones from their point of purchase. This could lead to potential legal action against sellers.
In January of last year, I was offered a spectacular natural alexandrite, a rare color-changing gem that is among the most expensive on the planet. An oval of diamonds surrounded the gorgeous stone, all set on a classic Tiffany & Co. platinum ring. A Philadelphia jeweler, with whom I'd done business, had bought it several weeks earlier from a well-dressed woman selling her mother's estate. To be prudent, the jeweler made his purchase contingent on an inspection by the Gemological Institute of America and the issuance of a GIA Lab certificate stating the alexandrite to be of natural origin, not man-made.
My eyes popped at its luscious beauty. At last, an essential prize for my gem portfolio. A world-class alexandrite with a world-trusted GIA certificate. What could go wrong? Everything, as it turned out. After certifying the alexandrite as natural, the GIA ultimately reversed course, concurring with another lab's analysis that the gem was a fake; it was possibly the creation of rogue scientists. What follows is a cautionary tale for anyone buying jewelry with expensive gemstones. Even if you're shopping at big, brand-name jewelers, it's wise to do a little probing. The good ones stand ready to help you.
5 November 2010: NEW YORK – American Gemological Laboratories (AGL): Following a presentation during the Gem-A conference recently held in London, England, Christopher P. Smith, President and Chief Gemologist of AGL was elected to Fellowship of the Gemmological Association of Great Britain (Gem-A). The presentation was made in the magnificent surroundings of Goldsmiths’ Hall, London.
“FGA credentials and affiliation with the Fellowship of the Gemmological Association of Great Britain, is our industry’s oldest and one of the most widely respected gemological honors.” Smith stated, “I feel very privileged to have received this special consideration and I am proud to become a member of this famous organization.”
Dr Jack Ogden, CEO of Gem-A said “Chris is highly respected internationally for his gemological research and he has demonstrated his commitment to upholding the standards of the gemstone and jewelry industry and furthering the advancement of gemology over the many years of his career. We are pleased to welcome him into our association and for him to become an FGA.”
By Christopher P. Smith, American Gemological Laboratories
Spinel has historically been one of the most highly revered gemstones. However, over an extended period of time, its popularity had suffered as a result of many factors, including its classification as “semi-precious” and a general confusion with another dominant red gemstone: ruby. More recently though, spinel has been making a strong comeback and so its popularity is once again on the rise.
Articles of important new
sources and even a book devoted to this beautiful and colorfully diverse
gemstone have helped to focus attention back onto spinel (see e.g.
Smith et.al., 2007; Senoble, 2008; Pardieu et.al., 2009; Krzemnicki,
2010; Yavorskyy and Hughes, 2010). In addition to exhibiting a vibrant
array of shades and nuances of color, spinel has also traditionally been
spared the controversy of treatments that have encumbered many other
gem varieties, such as ruby, sapphire, emerald, quartz, topaz and
tanzanite among others.
Fortunately, spinel remains a gemstone that is generally free of treatment considerations. However, today some treatments are starting to be encountered (Robertson, 2012). This article is a review of those treatments and the gemological characteristics that help to distinguish them.
Frequently Asked Questions:
Why not call this material Composite Ruby?
Although the extent of this treatment may be significant, there are several fundamental differences between this new treatment and the material AGL classifies as Composite Ruby. Of particular note, the glass infused into the Composite Ruby material contains lead and/or bismuth, as well as other potential elements to raise the refractive index of the glass to that of the host ruby. This makes it quite difficult to ascertain the true extent of the treatment without partially dissolving the glass. With this new treatment, it is readily visible through standard microscopy to determine the true extent of the healing and in-filling that has taken place.
Additionally, the lead-glass of Composite Ruby does not participate in the healing of fissures, and the golden color of the lead-glass further augments the color of a Composite Ruby. Neither of which is the case with this new treatment.
Lastly and perhaps most importantly, Composite Ruby carries with it certain intrinsic special care requirements that must be conveyed to bench jewelers and consumers, in order to make certain that inadvertent damage to these stones does not occur. This new ruby treatment has similar care considerations to that of the more traditionally heated rubies, which bench jewelers and consumers should already be familiar with.
NEW YORK, NY ― 13 November 2007 ― After several months of discussions with many sectors of the gemstone and jewelry trade in the U.S., Europe and Asia over concern that exists regarding the proper and adequate disclosure of the lead-glass treated rubies that are entering the market in large numbers, the American Gemological Laboratories (AGL) has decided to modify its disclosure policy regarding stones treated in this manner.
The gemstone industry was stunned in 2005 when the market began to be virtually flooded with large amounts of the lead-glass filled rubies for sale at very low prices, often as low as $2-$15 per carat (figure 1). “Those who have developed this treatment found a highly effective means of taking very low quality ruby that was available in massive quantities and turning it into more transparent, facet-grade ruby via a multiple-step process that involves stages of heating, acid cleaning, as well as injecting a high-refractive index glass,” explained C.R. “Cap” Beesley, President of AGL.