When I first became a gemologist in the late 1970’s I appreciated emeralds. Very little treatment over the centuries. Just a bit of oil to seal the surface-reaching characteristics and brighten the stone. Then, came Opticon a resin filler that greatly improved the overall appearance and introduced otherwise cheap material thereby crashing the emerald market. It has since recovered a bit and resins are now the norm.
I then came to appreciate sapphires – usually heated but nothing more. Then came the diffusion process, then beryllium diffusion screwing up both the blue and fancy colored sapphire markets respectively. Sapphires may still be cool but untreated reigns supreme.
Ruby? While almost always heated, the process of using a crucible with flux leeches synthetic inclusions into their natural host – sometimes making them almost indistinguishable from a synthetic ruby. Yikes!
Now the prevalent ruby has a lead-glass in-fill that makes them truly a composite of ruby and glass. Transparent material that has a $2000/carat look sells for about a hundred. Lower end stones are a couple bucks a carat. The problem is many stores are selling this stuff without knowing what it really is.
Case in point. An NGL client walks in for a ruby appraisal. The ruby is glass-filled and valued at a small fraction of what his Internet seller has offered it at. He swears off the Internet and goes to a mall jeweler to buy a legit ruby. The jeweler confirms that they do not sell glass-filled rubies and obtains a stone from a respected source. Back to NGL for confirmation and guess what? SAME MATERIAL. LEAD-GLASS FILLED RUBY. The jeweler thought they were safe. The consumer thought they were safe. The reality was otherwise as a two thousand dollar ruby sale was reveled to be a sham. This a prevalent occurrence and one that usually goes unnoticed because the public rarely checks out their purchases and jewelers do not have the equipment or expertise to verify every vendor every time.
While this material, has been around a while, it seems to now be commonplace as not only cheap Burmese but African material has been so treated. So when buying a ruby, have your source specify what they are selling and offer an unconditional money-back guarantee if it proves to be otherwise or you are not happy. Important (expensive) rubies should be certified by the GIA, AGTA, AGL or Gübelin Lab for treatment disclosures. Many other “labs” (and a lot from Asia) just do not cut it, so a certificate may only be worth the paper it is printed on. An opinion of value is then placed by an independent lab (one not ready to sell you another stone) that you trust. Remember, an appraisal is an opinion of value by that appraiser and may not be reflective of what you are paying in your transaction. The colored stone market is not only complex for individual evaluations but extremely variable because of sale conditions and markets that can fluctuate from local economies or global market conditions. You should always buy based on what you like, not an appraised value, but you should also get what you were promised.
For more on identifying gems and their treatments take our Gemstone Identification I & II class, then follow up with Gem Evaluation for pricing information and join us at the world’s best classroom, the Tucson Gem and Mineral Show.
Just got a call that has me riled up – again.
It was from a “diamond dealer” (“I am selling diamonds on the Internet so I must be a diamond dealer”) who started railing on me for under-appraising a clarity-enhanced stone he had sold to an NGL client. Although I instantly recognized his lack of knowledge in the area, I allowed him to “school” me on why following how GIA grades diamonds was akin to following Adolf Hitler (no, I’m not kidding). I think the main reason for his rant was because my value determination was less than 20% his retail representation based upon the document of his “highly reputable” laboratory in New York. Never mind that by his own admission, my “low” value still exceeded his transaction price by 40%. He couldn’t understand why his lab’s “value” of seven times the purchase price was out of line!
Sadly this is a scenario I see repeated over and over again. If the seller would just represent their goods fairly and not promise the sky, they would not lose their sales when guys like me appraise them. Unfortunately, “guys like them” love to inflate both the “clarity” grade and value of clarity-enhanced diamonds. I used “ ” around clarity because the nature of this enhancement precludes the Gemological Institute of America (GIA) from issuing a grade. They simply identify the process and return the diamond, un-graded. But, since there is a viable market for this product, the industry is left open to “call ‘em as they see ‘em” by establishing “visual-only” equivalent grades. More on that in a minute. But first…
This process was developed by Zvi Yehuda and came to market in the mid 1980’s simply known as the Yehuda process. Kind of like a windshield repair, surface-reaching feathers are filled with a glass-like substance rendering them less visible. Many others now utilize this technology but Yehuda maintains the best-known brand name in this business.
*APPRAISER’S NOTE: The clarity-enhancement process is a treatment to fill surface-reaching fractures with a foreign substance to render those characteristics less visible. The apparent color may also be affected by this process. While historically stable under normal wear, this treatment is not stable under the conditions of jewelry repair work. Disclosure is required to anyone conducting repairs to the mounting or to subsequent buyers. The Gemological Institute of America (GIA) does not assign clarity grades to clarity-enhanced diamonds. This report provides a visual-only equivalent for insurance coverage.
The preceding statement is part of every CE diamond we appraise. Yes NGL appraises CE diamonds, but only for the consumer (not the dealers) and then using proper GIA standards in establishing what “visual-only” means. Even though the GIA will not recognize them for grading, a segment of the public likes the idea of buying a diamond “enhanced” through this process. The pricing is higher than the original clarity but less than the “visual only” grading.
So, this glass in-filling makes the diamond appear better but how do we grade it? The GIA says no grade but the public wants to buy it, so the appraiser has to establish parameters for an insurance appraisal. The general rules for clarity grading say to examine five factors of the characteristic inclusions and blemishes and how they appear at 10X magnification.
Those factors are the size, number, location, color and nature of the characteristics. There is no particular order of importance, but a give and take between what relevance each has with respect to an individual diamond. The “nature” factor has to do with what type of characteristic it is. A feather, which is a break in the diamond, i.e. fracture or cleavage is the most severe but if tiny in size has minimal impact. A crystal is not by its nature too detrimental but if dark and eye-visible is another story.
Since feathers are the principal characteristics being affected by the CE process the nature aspect is changed only by a lessened visibility. The feather itself is still there to its full extent. While warranting a higher visual-only grade, the type of inclusion has not gone away. The treatment is not permanent so its removal would immediately downgrade the look of the diamond. These facts cannot be ignored, but most labs pre-grading this material for the diamond brokers and manufacturers seem to not only disregard them but forget to use 10X magnification in the process altogether!
The caller I alluded to at the outset claimed that the GIA process of grading was not the only way and since the gates are wide open for interpretation on CE diamonds, I see what he means. I have examined numerous diamonds that had eye-visible feathers after treatment and still looked I-1 or I-2, only to be graded SI-1 and above on the accompanying “lab” reports. As a GIA Graduate Gemologist, I elect to follow the old school five factors guideline.
Funny that in pricing CE diamonds I am fair and consistent with the product sold so I must know its price. So, why must nearly every CE diamond get high-graded from the original labs and given stupid values only to get refuted when in the hands of a legitimate appraiser?
The issue is further exacerbated by non-disclosure many sales involve or the cryptic way the treatment is revealed. While the Yehuda folks and others have full disclosure, guarantees, etc. most of the sales we see come from second, third or fourth parties. We have addressed that before, so I won’t dwell on the issue. I merely want people to be reasonable in their representations, not hide behind bogus lab reports (which do not obfuscate the seller’s responsibility anyway) and make a fair profit selling something the public wants. Just like kids soccer – everyone wins!
To learn more about clarity-enhanced diamonds and how to identify them, take our Diamond Grading class where you will examine them as well as substitutes and synthetics.
It seems like there’s another gem treatment around every corner these days. While gemologists have to stay on their toes to keep up, a curious consumer just gets more confused over what is natural, synthetic and treated – and their jeweler may not know.
As gemologists we have seen inclusions (what we need to identify origin) change over the years to make the identification of treatments more challenging than straight synthetics. So when Tom Chatham, (Chatham Created Gems) was speaking at a recent GIA Alumni presentation about the history of his company’s “creations” and the properties of these new inclusions in natural gemstones, he asked the question “Where do we draw the line between natural and synthetic?” A very good question since more and more natural stones are altered with synthetic foreign material. Is a glass-filled ruby still a natural ruby? The material may be red corundum (ruby) but with synthetic features including flux residues. Flux residues are a major characteristic of synthetic flux-melt rubies! We might think the stone was of a synthetic origin. Well, part of it is. Of course, a ruby may owe its color entirely to treatment to begin with. What used to be a venerable gemstone has definitely been tainted due to these treatments.
While the industry allows “traditional” treatments to gems it tends to shun radical means of color enhancement until enough people are doing it to add that treatment to the tradition. As long as the consumer wants purer color in their gems, there will be a market for whatever treatment brings it to them. Every day, consumers at the supermarket buy artificially enhanced produce over organic because it looks better, so it’s not surprising.
Each year, I take a small number of my gem students to the world’s biggest gem and mineral show in Tucson, Arizona early February. This year our contingent researched gem prices, bought a little (some a lot) and made future contacts.
What’s Hot? After many years of speculation, Tanzanite has finally gotten a more solid base price – not as much from new material but the selling off of old stones at firmer prices. The future should be interesting, what with a push for more localized production, selling though a cartel style arrangement and price ”augmentation” to stratify the production into a wider range of qualities– we’ll see. And as prices for the best material approaches that of decent blue sapphire, why would one want a brittle, heat induced zoisite instead of durable sapphire, anyway? Maybe I will do an article on the tanzanite hype, next time.
Pink stuff is hotter than ever. Sapphires, tourmaline, topaz, spinel, etc. are still trendy. Last year’s Be-diffusion scare on sapphires seems to have subsided, but bear in mind it can take a pink sapphire to a 1/10th its apparent value. Be – ware. (Be means beryllium treatment, a diffusion process that induces color at a nearly undetectable rate and has made orange sapphire almost un-saleable). Because other colors can also be created the endorsement of un-treated gems has gained increased marketability.
Pearls are more stable this year, with better management of Tahitian production and marketing, more controlled Chinese production and sale and higher end products available. Interesting multi-color strands of mixed regions (Tahitian, South Sea, Philippine, etc.) were more prevalent. Some had natural and treated colors and a few were guaranteed to be of natural coloration.
Next year’s Tucson class roster is already filling, and with the right gem course prerequisites, you could join us.
Yes. The problem is you don’t know which until you check them out. We have had some very happy clients who purchased over the internet – and some very upset ones.
In one instance, the client received an appraisal which failed to clearly state that they were buying a clarity-enhanced (fracture-filled) diamond, and the value stated was three times higher than what was paid. The NGL appraisal placed the retail value close to what was paid with prominent disclosure of the enhancement process. On the other hand, we have verified many great purchases, especially when GIA or AGS was the certifying lab and everything checked out.
We have also seen a lot of misleading colored stone transactions on-line. The biggest area seems to be in the emerald market, where stones too light to pass as emerald are being sold as “Colombian emerald”. True, they may be Colombian in origin, but cannot be gemologially classified as emerald if not at least medium-light in tone. On the other hand, many colored stones bought on-line price out significantly more than their transaction price – but remember, price is not the most important factor anyway. The best advice is to obtain a guaranteed refund if not satisfied.
It has been seven years since Zvi Yehuda was credited with the process that fills surface-reaching fractures in diamonds, giving them an apparent clarity improvement.
What have we learned since then and how will the industry handle the on-going debate aver its use?
Over the past five years, NGL newsletters have reported on the process, its telltale signs and ethical concerns as has the GIA and numerous trade publications.
As gemologists, we are concerned over the grading aspect. If a fracture is filled it hasn’t gone away. It may be less visible but its true nature hasn’t appreciably changed.
It’s like clarity grading with the naked eye and saying “If you can’t see it, it doesn’t count.”
There is no standard industry position on the fracture-filled diamond. Some labs will grade them – some will not. GIA will not. EGL did but now does not.
NGL’s position is as it was in the beginning. We will identify the treatment and issue a report as such but not assign a clarity grade or value [Editor’s Note, 2008: NGL will offer appraisals to the end consumer only on fracture-filled stones. It will include a visual-only clarity grade along with a disclaimer and a value for insurance purposes only.]
What sets this policy for us is the fact that it is not stable in a diamond’s normal environment. Everyday wear is fine, steam cleaning and an ultrasonic may even be OK for some, but a “normal” environment for a diamond includes being subjected to the heat of the jeweler’s torch and under those conditions the process is highly unstable.
The effects are obvious and the consequences for the unsuspecting jeweler are not pleasant. It cost one jeweler his life and may cost others their livelihood.
The latest technological breakthrough in gem enhancement – the “Yehuda” treatment for diamonds is sure to spark controversy throughout the industry, as these enhanced stones filter into the marketplace and cause concern over their disclosure and evaluation.
The treatment developed by inventor Zvi Yehuda of Israel is not unlike modern emerald oiling in that a foreign substance is forced into surface fractures to stabilize and enhance appearance. In emerald, the material is an oil, but in the Yehuda process, a glass-like substance is introduced under extreme pressure. Since the substance replaces air within the stone, the inclusion becomes much less visible to the naked eye, – and virtually invisible if its refractive index approximates its host
Although some secrecy surrounds the process itself, the effect can be readily observed by the trained gemologist.
Microscopic examination may reveal the flow structure, trapped bubbles and an overall crackled texture, or characteristic flash. The filler’s color may also be darker than the host diamond.
These factors cause great concern to those involved in the evaluation of such diamonds. Stones tested by both the Gemological Institute of America (GIA) and American Gemological Laboratories (AGL) showed many graded higher in clarity when filled. Should appraisers grade on the treated appearance or try to “backtrack” to the prior condition? If the filled material imparts color (tests reveal commonly one grade lower than when untreated) how do we judge the new product?
In fact, color causes its own grading problems. The nature of the process and type of inclusions being altered often creates a “directional” color in the diamond. A single specimen appears to grade differently depending upon the angle of observation.
What the “big guys” say
The stance of the GIA is to currently refuse evaluation of Yehuda-treated diamonds. AGL advocates the development of a system to grade such stones realizing that conventional techniques are stretched to the limit and require modification to accommodate these stones.
Jewelers have their own problems. Although Yehuda-treated diamonds are accompanied by a disclosed pledge for the dealer when returned from their treatment facility, Diascience, INC. in new York when the diamonds change hands, the disclosure aspect often gets lost in the shuffle and may be sold as untreated. A retail customer not made aware of this fact has recourse when the truth is known and the reflection is certainly upon the jeweler, not their suppliers. And, the unaware bench jeweler repairing an article with such a treated diamond may unknowingly release the filler material through the heat from their torch, returning the diamond to its original condition. What will the diamond’s owner say when it is returned to them?
Since the Northwest market is not yet familiar with these diamonds, this is the time to investigate the issues raised and form a basis for evaluation. As the major appraiser of fine jewelry in this market, NGL is in the process of forming a policy concerning these diamonds. We welcome your opinions on this issue and will publish some of those comments as well as our findings in future issues.