AGTA GTC's Laboratory Update for March 27, 2007
In this message…
- FTIR Intrigue, Part Deux
- Treated Ruby With Multiple Personality Disorder
- Thailand and Japan reach Beryllium Agreement
- Upcoming Lectures
Acetone is sometimes used to clean specimens prior to taking an FTIR spectrum, the idea being that this will remove surface contaminants. But one must take great care that the acetone itself is not contaminated, as the following two spectra show.
FTIR spectrum of the same orange sapphire taken before (red) and after (blue) the gem was dipped in acetone. One can clearly see that the acetone has actually contaminated the specimen, producing large oil peaks where only tiny ones existed before. |
In Tucson I performed a brief experiment that shows the potential perils of acetone cleaning as it relates to the FTIR. First, the FTIR spectrum was run on the specimen without any sample preparation other than wiping with a gem cloth. Then, the gem was dipped into a bottle of acetone that had been previously used to clean many specimens. Following a quick dip, the excess acetone was removed with a paper towel (without touching the gem) and the spectrum re-run. The result was distinctive, with large oil peaks found following the acetone bath.
This simple experiment makes clear that acetone dipping has many perils with the FTIR. As a powerful solvent, it will dissolve oils and other dirt that might be on the specimen, but this then leaves a residue as the acetone evaporates. Even if the gem is carefully wiped clean following this dipping, one can suppose that residue would still remain in pits and fissures that escape the touch of the wiping medium.
The lesson is that acetone "cleaning" may add contamination, rather than remove it. If acetone is to be used at all (and the above suggests it should not), one should use clean acetone for every dipping.
Dr. John Emmett had the following comments on the idea of cleaning a specimen in acetone prior to testing with the FTIR:
Washing a stone in anything without knowing the spectra of it is not advisable. First, use semiconductor-grade solvents and only use them once. Second, know the spectra of the pure solvent so you know where in the spectrum to look for interferences and for solvent in cracks. Third, you can measure the spectra of even volatile solvents by putting a drop between two pieces of polished synthetic sapphire plates. Run the spectra of the plates without solvent first. Using paint store solvents for multiple cleanings is worse than no cleaning.
Treated Ruby With Multiple Personality Disorder
We received a large ruby (>10 ct) for identification. Microscopic examination revealed evidence of high-temperature heat treatment, to an extent where we were not even sure if it was a natural stone. When immersed in di-iodomethane, a telltale orange rim was seen, suggesting beryllium diffusion. Before doing LIBS testing for beryllium, we performed EDXRF to determine natural versus synthetic origin. The chemistry not only revealed the gem to be natural (due to the gallium content), but it also revealed the presence of lead. LIBS testing gave us a stronger than normal beryllium peak.
Just how does a gem end up with both beryllium and lead? Good question. Lead is a component of some fluxes. In addition, lead is a major component of the glasses used to fill fractures in ruby. We speculate that the gem may have originally been filled with lead glass and later beryllium treated. The lead-glass treatment is normally done at low temperatures, while beryllium diffusion takes place at much higher temperatures. This was a gem with a true multiple personality disorder.
The ruby in question. |
This overview shows that the gemstone was originally heavily fractured and subsequently flux healed. Photo: Hpone-Phyo K. Nyunt/AGTA GTC. |
High magnification revealed that the bubbles were surrounded by a darker fluid, which has not been observed in “traditional” flux healing. The size of the bubbles is approximately 5 μm. Photo: Lore Kiefert/AGTA GTC. |
Synthetic overgrowth on the surface of a re-polished ruby indicates that the gemstone was heated at high temperatures. Such a phenomenon has been observed in many of the pinkish orange Be-treated sapphires. Photo: Hpone Phyo K. Nyunt/AGTA GTC. |
LIBS spectrum for the ruby in question, showing the strong beryllium peak at 313 nm. |
Thai and Japanese Trade Associations Reach Beryllium Agreement
On March 14, 2007, representatives of the Thai Gem and Jewelry Traders Association (TGJTA) and Japan Jewelry Association (JJA) announced an agreement regarding the disclosure of beryllium (Be) treatments in corundum. Other signatories were the Thai Department of Export Promotion (DEP) of the Thai Ministry of Commerce; the Gem and Jewelry Institute of Thailand (GIT); and the Chanthaburi Gem and Jewelry Traders Association (CGA).
The memorandum states that exporters of loose corundum must disclose the treatment on invoices using the following terminology:
- Non- Be-Treated
- Be Treated
- Unconfirmed Be Treatment
The JJA asked that the same disclosure rules also be applied to jewelry set with corundum.
In Thailand, compliance with these rules is to be enforced under the rules of the TGTJA, while the JJA confirmed that its members must follow the same disclosure standard in their domestic transactions. Cases of non-compliance will be dealt with under the rules of the Japanese association.
Both parties resolved to establish a set of similar disclosure standards for beryllium identification with support from gem laboratories in both countries. In addition, both parties will ask their local gem labs to conduct joint research in order to strengthen the disclosure procedure.
For corundum exported to Japan without proper disclosure and subsequently found to contain beryllium, the Thai exporter shall accept the return of the stone and make a full refund to the buyer. However, TGJTA requested that the disclosure procedure should also be applied by all other countries that export corundum to Japan. The JJA said it would give this issue its highest priority.
The TGJTA proposed to the JJA to make information about beryllium treatment available to the downstream market, i.e. to the retail and consumer levels. The JJA welcomed this proposal.
Finally, the TGJTA proposed to create a "Cluster Blue Sapphire Group" that would export only non- Be-treated corundum. Once such a group is formed, the list of member companies will be made available to the JJA and will be distributed among its members.
Upcoming Lectures
AGTA GTC staff will be busy in the coming months with the following lectures:
Pasadena, CA, Saturday, March 31, 2007 
- Jade: Stone of Heaven
Richard W. Hughes, AGTA Gemological Testing Center
Saturday, March 31, 2007, 2:00 p.m.
Pacific Asia Museum
46 North Los Robles Avenue, Pasadena, California 91101
Tel: 626-449-2742
Known to the Chinese as the "Stone of Heaven," jade is one of mankind's most beguiling gemstones. While the term "jade" includes both nephrite and jadeite, only jadeite occurs in the coveted "imperial" type, and for this the world has but one source, Upper Burma. It is these mines which are the subject of this program.
Burma's center of jade mining is the small town of Hpakan. Fortune-seekers from all over Asia are drawn to the mines and the heady atmosphere is one of the gold rush days of the old American West. Famous in Burma as "Little Hong Kong," Hpakan offers Hennessy cognac, Rolex watches, French perfume and much more. This is all the more amazing considering the difficulty of getting there, as it is located amidst some of the most impenetrable jungles on the planet.
In 1996, Richard Hughes was a member of the first foreign gemological party allowed into these mines in over 30 years and will regale participants with a first-hand account of the mining and trading of this fascinating gemstone.
Washington, DC, Monday, April 9, 2007, GIA Alumni, DC Chapter 
People & Places: New Directions in Gemology
Richard W. Hughes , AGTA Gemological Testing Center
Monday, April 9, 2007, 7:00 p.m.
Holiday Inn Rosslyn, 1900 Ft. Meyers Drive, Arlington, VA 22209
Tel: 202-342-3943
Gemology is tired. Weary. Stumbling. Guilty. We are privileged to work with some of the most stunning and romantic objects on the planet – singular marvels of incredible beauty. And yet all we can do is analyze. Like sadists, we torture beauty until the extraordinary is reduced to the ordinary – chemicals, numbers and digits – abstractions with no relation to the reasons why people are drawn to precious stones. We break the butterfly upon the wheel.
Which instrument comprehends feeling? What tool measures emotion? No device can see with our eyes nor read our minds. Yet we surrender our senses to the machine. Guilty as charged. We break the butterfly upon the wheel.
Gemology cannot be simply science. People are drawn to precious stones because of passions, not just properties. The purchase of a precious stone is an emotional contract that connects the new owner with people and places across the planet. If we wish to fathom desire, we must begin understanding this visceral link. And if answers are not easily measured, if they involve emotion and art, not just science, they are no less real and no less important to gemology.
Richard Hughes will delve into these issues via a dramatic multimedia presentation that covers ground all the way from Manhattan, through Russia's emerald mines, to Madagascar and Tajikistan's remote ruby, sapphire and spinel deposits.
It will provide inspiration, a new direction into the neglected, nether regions of gemology. Don't miss it.
Denver, CO, April 25–28, 2007, AGS Conclave 
Solid Steps to Successful Colored Gemstone Sales
Douglas Hucker, AGTA
Friday, April 27, 2007, 11:00–11:45 a.m.
AGTA's Chief Executive Officer explores the critical components of a dynamic and successful colored gemstone jewelry presentation. What motivates your customer to buy color? What are their major concerns when doing so? Learn the basic components that must be included in every presentation to dramatically improve your success rate. Identify your most powerful sales tools, including a thorough discussion of the AGTA GTC Colored Gemstone Reports and the critical part they play in the sales presentation.
AGTA Laboratory Highlights
Dr. Lore Kiefert, AGTA GTC
Friday, April 27, 2007, 3:45–4:45 p.m.
Join Lore Kiefert as she brings you up-to-date on current issues in day-to-day gemstone testing: the treatment of emerald, ruby, sapphire and pearls; new sources of these gemstones and the confusion when these first arrive on the market unnoticed; and the detection of synthetics and imitations. These challenges are presented using current examples the laboratory has encountered. Unusual and rare cases of gemstone testing also will be introduced.
Take the Vow with Color
Douglas Hucker, AGTA
Saturday, April 28, 2007, 2:30–3:30 p.m.
Colored gemstones and cultured pearls have a rich tradition as betrothal gifts, and their presence in this all-important lifetime event is on the rise. This seminar will look back on the rich history of gemstones and cultured pearls in the wedding ceremony. Let's consider how you, the 21st Century American Gem Society jeweler, can introduce these beautiful treasures to your clients who are preparing to take the vow and "something old" indeed becomes "something new.
