Archive for the ‘science’ Category

For those who do not know, almost all (>99%) of blue topaz available obtains its color via neutron or electron radiation.  The sources of irradiation are either the inside of a nuclear reactor core, or a linear accelerator.  This has been a long standing practice, and as most people know (even the lay person), blue topaz has been readily available in the United States for a long long time.  What most people don’t know are the legal aspects of it.  David Federman of Colored Stone put it well by stating according to the Nuclear Regulatory Commission, “…all topaz blued in a nuclear reactor is illegal for sale unless tested and cleared by a NRC-licensed distributor.  Since there are no licensed distributors in America, all “London Blue” topaz imported into this country in the past decade is technically classifiable as contraband”.  Earlier this past spring, the NRC finally figured out their own policy on this and sent out heart felt letters to major jewelry retailers, demanding the names of their blue topaz suppliers and warning them that purchasing the material was against the law.  The retailers of course quickly pulled all material from their shelves.

The Nuclear Regulatory Commission then sought the help of the Gemological Institute of America (GIA) and the American Gem Trade Association (AGTA), to obtain all of the testing data for blue topaz.  Armed with this information, their next step which has been carried out up through September has been to go to New York and test random sample batches of stones from dealers.  The results from this testing were that all batches, but one, tested at levels consistent with background radiation; while the other batch tested at twice the level of background radiation.

Duncan White, chief of the NRC’s State Agreements and Industrial Safety Branch, said that “Thus far, the NRC has found no health or safety problems, and consequently is considering an approach that would substantially soften the impact of its renewed attention to irradiated gem.  Right now, we are considering ‘grandfathering’ existing inventories of all blue topaz within the U.S. – allowing companies to sell their goods and applying new requirements to material still overseas”.  Duncan White offered no definitive answer on when this would become effective, but stated the NRC is continuing to test blue topaz material from other sources until it can be concluded there is no threat to the public.

Currently, many in the industry state that they are reluctant to consider selling blue topaz any time soon for fear of lawsuits.  Others have experimented by substituting diffusion-coated blue topaz for the irradiated material.  Diffusion-coated blue topaz derives its color from an electro-coated layer on a colorless stone.

Personally, I think all of this material is garbage, along with any variety of cheaply treated stones including mystic topaz, london blue topaz, swiss blue topaz, etc.  If I never saw another piece at a show I could not be happier, and I only publish this article in the interest of current events.

“London Blue” Topaz 

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Before I go into a long tirade about this, let’s first examine the last major Thailand scam…

The last time the gem world was rocked by dishonest Thai dealers using atrocious practices targeted corundum, specifically sapphires which were subjected to beryllium diffusion. Beryllium diffused sapphires were released like the Great Flood upon the market into the hands of unsuspecting dealers. The problem was so great that it threatened to cripple the market for sapphires. Beryllium treatment is a process that replaces the trivalent aluminum in the crystal lattice with divalent beryllium. The color change process is very complicated, and due to this, other trace elements often give away a signature that can be detected. Without going into extreme detail (which would take pages to discuss), a brief example of Be treatment could be when: [Mg2+ + Be2+] > [Ti4+ + Si4+] a trapped hole of color is formed by Be2+ and Mg2+ to produce yellow color. If though instead you reverse this process so that [Ti4+ + Si4+] > [Mg2+ + Be2+], more donating electron ions exist to deform the trapped color hole and yellow color is not produced. Blue color can be produced in sapphires using the transfer of Fe2+/Ti4+. This practice lasted for years, even though gemologists could detect the process, many dealers passed the stones along unknowingly representing them as legitimate heat treated only or worse yet, natural untreated gems. For the most part this problem has settled down, but still rampantly plagues online auction venues such as eBay.

Now, in regards to Thailand and topaz… The industry has been aware of inexpensive colorless or light tan topaz being treated with Cobalt-60 radiation or X-Ray radiation that turns the stones into a lovely deep reddish/orange to deep pinkish-brown color. The purpose of this would be of course, none other than to defraud a buyer by making the material appear to be very costly precious or imperial topaz. The problem is, that with only 1 day’s worth of exposure to natural sunlight, the process is completely destabilized, and the material’s color washes out to it’s original color (or lack thereof rather).

The difference in price between common colorless/tan topaz and true imperial topaz is a difference between as little as $1-5/ct for common material and upwards of $1,000/ct for stones 10cts+ in size of super rich color imperial topaz. This practice has had an immense impact on the trade and is the equivalent of taking a direct hit by a 20 megaton hydrogen bomb. It is a seriously destabilizing move against the industry by fraudulent individuals.

This case has become rather personal for me, in that someone I am close to has been affected by this scam. The individual purchased a 30 ct+ topaz from a dealer that operates off of eBay. The material was represented as untreated and was sold for about $1000 for the stone. This unfortunately should have been the individual’s first clue, when the material was priced around $30-35/ct, that this could not possibly be the famed material from Oro Preto, Brazil that commands prices of $500-1000/ct in sizable stones. But regardless, this person was misled – as the material was represented by the dealer as untreated. Upon seeing this material, I immediately knew that something was dead wrong. The saturation was too deep, there were a couple bands of internal color zoning that are atypical of zoning formations of precious topaz, and it flat out just didn’t look right. Upon suspecting the worst, I gave my opinion on the material, and suggested that we subject it to natural sunlight. I took pictures prior to subjecting the stone to natural light. Unfortunately, I didn’t have any AA batteries available for my digital camera, so I used a film camera (hope the shots came out ok). When I develop the pictures I will upload them here.

The process was timed to expose the material for 8 hrs to direct sunlight. What happened within the first hour of exposure alone was horrifying… the material lost half of it’s color saturation. Within subsequent hours, the material lost more and more color saturation. What started out as a very deep gorgeous reddish brown topaz was reduced to barely a light tan stone within 5 hours. eBay is still a huge source, if not the number one source of this treated material. I can’t stress enough how important it is to know your source and know what you are buying and what treatments are out there.

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Over the summer I have come across various examples of unusual minerals; and much of it was in it’s natural crystal form or aggregate. Of course I have seen a good deal of faceted rarities and exotics as well over the past 3 months, but nothing was as quite as strange as a 15+ carat gem someone showed me in August. At arms length away, the stone appeared to be pure black in color, opaque, with a high polish but a resinous luster. At this point, I thought to myself… well good for you, you have a nice chunk of poorly crystallized carbon (black diamond), and for a split second I was trying to imagine how I would pull off being excited by this stone. But upon an initial look at the stone, even without a loupe I knew that his was not a black diamond at all. My interest was piqued at this point, and I louped the stone for the tell tale micro breaks in the surfaces of black diamonds. There were none in this stone. The heft of the stone was far too much to be a diamond, I knew that right away as well. Without performing a specific gravity test on it, I knew that it was far more dense than a diamond would be of that size. I finally asked the gentleman “Ok, what is it?” He replied: “Thorite.” At this point I was shocked for two reasons: 1) I have never heard of anyone faceting thorite and 2) why would you want to in the first place?

For those who may be unfamiliar with this material, thorite is a rare nesosilicate of thorium (yes… that’s right, Thorium). Upon first glance at its composition, one might be able to conjure up feelings of shock I felt upon hearing its name… (Th,U)SiO4. It is in reality the most common Thorium mineral (as common as that is I suppose). It usually occurs in granular pegmatites, but can can occasionally form crystals. It is always strongly radioactive. Webmineral.com lists the mineral as having an estimated mRem/hr exposure of 0.421 per gram if held in your hand for 1 hr (if the stone is set in a ring, it’s on your hand). This was about a 15 ct. stone so 15 cts / 5 cts/gram = 3 grams , therefore 3 g Thorite x (0.421 mRem/hr per 1g Thorite) = 1.263 mRem/hr exposure from this particular stone. While this might not be a lot of exposure if you’re just picking it up to examine it, I’m not sure I’d want to expose myself to it for say 8 hrs/day a few days per week (and if you put it in a pendant due to it’s lack of hardness, that’s even better – now you’re exposing your more sensitive neck/chest area). Prolonged exposure to any radioactive source like that, especially in the same place on your body day after day doesn’t appeal to me. The source of this piece was Burma, and I listened its owner explain that there is a developing market for exotic/super-rare pieces among collectors. I explained that I considered materials like painite, benitoite, jeremejevite and taaffeite to be exotics/super-rare and also beautiful — as well as non toxic and definitely not radioactive. When asked if he had any luck selling any of it (priced at a little over $100/carat), he said not as of yet. In my personal opinion I can see why… it’s not a pretty stone (just solid opaque black), its very soft (4.5 on the Moh’s scale), it’s radioactive (which you have to disclose), and its $100/ct… I can think of many types of stones in that price range that are infinitely more attractive, more durable, and more practical than Thorite. Hey… you know Uraninite (UO2) forms black crystals too… how much more exotic would that be? Get a grip.

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From my personal perspective HPHT is a four letter word. The acronym HPHT stands for High Pressure – High Temperature, and refers to an artificial process that some diamonds are subjected to in order to “reinstate their natural beauty”. Certain companies such as General Electric, have found an efficient process of turning natural Type IIA diamonds (no nitrogen present in the crystal lattice), that happen to have undergone turbulence or irregular pressure on their journey through volcanic pipes on their way to the earth’s surface, into colorless, pink, or even blue diamonds. Type IIA diamonds are the most rare diamond type, accounting for less than 2% of all diamonds mined. Originally, prior to HPHT treatment, these stones were mostly an undesirable yellowish brown color. HPHT can also turn Type IA diamonds (the most common diamond type), into green, yellow-green, or yellow diamonds after the process is complete. In a quick synopsis, HPHT subjects gemological imperfect diamonds to an ideal high pressure and high temperature setting that they never received in nature. This is the basis for a “controversy” between businesses who perform the process, the FTC, consumers, and oh yeah… gemologists. Thankfully the FTC has declared that any diamond subjected to HPHT has to have the process disclosed to the consumer. Unfortunately, this serves as little more than another platform to confuse most consumers on, since most consumers are not gemologists. Consumers tend to buy off of aesthetic appeal and emotion based decisions. Even informed consumers may not know a diamond has been subjected to the HPHT process, because the process is difficult to detect without costly equipment and proper training. Many seasoned gemologists have been deceived by HPHT (or have been intentionally set up by the GIA for training purposes *smile*). The bottom line, both personally, and from a gemology perspective, is that any stone that has been subjected to any artificial process – regardless of whether that process mimicks nature or not – is that the process should be disclosed to the consumer. The GIA has dedicated its time, finances, and efforts to not only detecting HPHT diamonds and noting them as such, but also to increasing awareness to consumers – and gemologists worldwide. It’s still a treated stone stupid… period.

Courtesy of Argyle Diamonds

Argyle’s natural rough diamonds are sorted at its Perth office where they are prepared for international sale by Rio Tinto Diamonds as an agent for Argyle Diamonds in Antwerp Belgium.


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In September of 2003, around the timeframe of the ratification of the Kimberly Process by the United Nations, Wired Magazine (article is found here) decided to properly cover a blossoming area of the gemological field: lab created diamonds. They are not similar to diamonds… they are diamonds, both chemically and physically. Historically, Russian scientists have had the technology to produce gem quality diamonds, but never reliably or on any sort of a large scale operation. In fact General Electric produced diamonds decades ago for industrial purposes mostly, but the stones were always small (around 1/2 – 1 carat). That has now changed. Today everyone is getting in on the action – from the United States Navy Research Lab, to start up companies Gemesis and Apollo Diamonds, and they are producing large diamonds predictably and efficiently. The biggest use for lab created diamonds at this juncture in time seems to be not in the gem realm, but rather in the semiconductor world.

It is interesting to note how the leaders of both companies received personal messages people assuredly sent by DeBeers, stating that progressing with lab diamond technology is a perfect way to get a bullet in the head. At this time the ink on the Kimberly Process ratification was barely dry, DeBeers had already been publicly shamed – yet they were continuing with their typical show of force in a war that they know they are losing ground.

A little over 3 years after this story, it appears that the demand for lab created diamonds in the jewelry realm is very minimal. I regard this as a good thing, as it is easy to reproduce many gems that occur in nature and that are valuable, with great ease and relatively low cost. To the credit of many of these lab created gems, they are beautiful – even capturing inclusions and imperfections that would occur in nature, in the lab stone; but nothing compares to the beauty of something that took millions and millions of years to form, instead of something that took 3 days to whip up in a clean room.

Faceted lab created yellow diamonds from Gemesis — Identical chemically and physically to stones of natural origin.

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A work in progress…

It will take me some time to gather my thoughts on how best to assemble this site to the benefit of all its intended viewers. Whether you are a broker or collector, the goal of this site is to focus on our commonality, and in turn further advance our knowledge and appreciation for our passion. My initial plans are to broadly cover the basics of a different mineral every week, and its applications to the gemological realm. I am considering structuring this on a thread based setup, in which each mineral will have perpetual updates. This will serve as an informative foundation upon which to further build the rest of the site. Of course updates regarding current trends, speculative trends, and jewelry ideas and information will also be included in these building blocks. Any individual who would like to showcase anything in their personal collection is more than welcome to post pictures, information, and personal thoughts on any piece of rough or faceted material. I wish to take a moment to ask everyone who is interested in any aspect of the field to provide insight on what they would like to see accomplished by this site.

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