Treasure From France: URANIUM!

A True Tale of Ceramic Adventure and Intrigue

The following story took place while I was in Southern France for two weeks attending Crystallines 2005, an international crystalline glaze symposium. It culminates in my acquisition of Uranium oxide. Uranium oxide, for those not afraid of its associated dangers, is one of the "holy grails" of glaze colorants for crystalline glazers like myself.

An ochre-colored church near Grasse, France. Looking south towards Cannes
which is about 10 miles away on the Mediterranean Sea coast, the Côte d'Azur.

The Quest for Ochre

Before I left on my trip to Crystallines 2005, a painter friend suggested that I should buy ochre while in France. Ochre, or yellow ochre (there are other types), is a naturally occurring mineral comprised mostly of clay, typically about 75%, and of red iron oxide, about 20%. In addition, it has trace amounts of some other interesting "wild card" elements, which are one of its main attractions to me as a crystalline glaze colorant. Yellow ochre is usable almost exactly as it comes out of the ground, with no processing other than pulverizing. Some of the world's most famous and historically significant ochre mines are in France.


I had pretty much forgotten all about obtaining ochre while I was in France until I visited Cézanne's atelier (studio) in the town of Aix-en-Provence, where a guide mentioned it. Suddenly, I had a welcome new purpose, a sub-mission to occupy my vacation time: to find and acquire ochre.


Even if ochre turned out to be a failure as a crystalline glaze colorant, it is still an interesting material to have around. For thousands of years it has been mixed with linseed oil and used as an oil paint. It is also used in acrylic paint, in frescoes, in lime washes and to color mortars. The pleasantly earth-toned houses and buildings that are synonymous with southern France are stuccoed with ochre-colored mortars. For an artist, ochre is a great souvenir to have of a French vacation.


Gallery Torres, Vallauris, France. Crystalline-glazed porcelain by Cat Torres,
paintings by Chris Torres.

My search for ochre began at the atelier/gallery of Christopher and Catherine Torres in Vallauris, France.


Catherine "Cat" Torres is a crystalline glaze artist and a member of AVGECAA, the foundation which sponsored and organized Crystallines 2005. Her husband Chris is a painter. Both were very gracious and spoke excellent English, and I knew that they could help me on my quest.


The Plot Thickens

At Gallery Torres, Chris gave me some leads on purchasing ochre. Now that he was aware of my interest in unusual glaze colorants, he reached into a closet and pulled out a clear glass jelly-jar filled with a bright yellow powder. "Here's something really unique," he said. "Uranium oxide."


My heart immediately began pounding a little faster. Uranium oxide produces vibrant colors in crystalline glazes that are unobtainable by other means. I have always wanted to experiment with it. However, uranium oxide is extremely hard to purchase in the U.S., and is very expensive. "Where did you get it?" I asked.


Chris told me that Monsieur Roger Collet, a potter whom I had previously met, had given the uranium to him. Monsieur Collet is one of Vallauris's "elder statesmen," a well-established and respected artist who works in a style similar to David Leach. The earlier day, when we broke for lunch from the Crystallines 2005 seminar, the audience was invited to tour Monsieur Collet's studio. The attractive gallery was housed in a rustic, arched space, with a very interesting throwing and workroom up a flight of stairs.


Monsieur Roger Collet's gallery Space.
Christian Torres is in the white shirt.
Roger Collet's throwing area.

Monsieur Collet's father had also been a potter. (Since I haven't yet mentioned it, I should say that Vallauris is famous as a pottery community. It is bursting with potters and artists, and with studios, galleries and shops selling a multitude of ceramic objects in a variety of styles. Vallauris is where Picasso produced his ceramic artworks.) Monsieur Collet inherited his uranium from his potter father, but neither had ever used it. Now, Monsieur Collet wanted to pass some of it on to interested ceramic artists who could make use of it. Well, I was interested, and I could use it, and an appointment with Monsieur Collet was set up for the next day.

Roger Collet and William Melstrom
A view of Roger Collet's work area.
This is what 50 pounds of yellowcake uranium oxide looks like.
I wish that I had thought to photograph Monsieur Collet's barrel of
yellowcake, but it didn't occur to me at the time -- this image was
found on the Internet. Monsieur Collet's yellowcake looked just like
this, except that his was not in a steel barrel --
it was in a cardboard barrel!

Yellow Gold

The next day, after greetings and salutations, Monsieur Collet reached under a worktable and pulled out a big old barrel that has been in his family for about fifty years. With no protection at all, no gloves or respirator, he pried the lid off and revealed what must have been about twenty-five kilos of bright yellow, powdered "gold." I was flabbergasted. Monsieur Collet gave me a spoon for a scoop and some plastic 35-millimeter film canisters to fill. Again, with no protection, I filled two of the canisters, trying not to breathe while I did so.


At this point, I had absolutely no idea what I was really dealing with or how dangerous it might be. Monsieur Collet claimed that the material was "depleted" uranium oxide and was completely safe and non-radioactive. I wasn't even sure that it really was uranium. It could have just as easily been something entirely different, such as vanadium pentoxide or a mason stain. Or, it could have been something really toxic and radioactive, in which case getting it back to the United States could be problematic and perhaps even illegal. So, although I probably could have taken as much as I wanted to for free, I only took the two film canister's amount.


Back on the Ochre Trail

From Monsieur Collet's studio I proceeded towards Antibes where I procured two kilos of ochre without too much problem from the Ceradel Socor company. Ceradel is a major supplier of ceramic materials and equipment in France, and was a sponsor of Crystallines 2005.


Cannes, Vallauris, and Saint Paul, France.

At this point, I will digress a bit for a moment, and mention that this journey was being carried out on a bicycle that I had rented in Cannes, where I was staying. After the "business" of getting my uranium and ochre, my ultimate goal that day was to bicycle to the town of Saint Paul. Diane Creber, the author of the first book ever written about crystalline glazes, and a Crystallines 2005 participant, and her partner Tim De Rose, had earlier rented a car and visited Saint Paul and had raved about it. Indeed, Saint Paul was my favorite place in France.


Saint Paul de Vence, France.

Saint Paul is a picturesque, ancient, fortified, "perched" town, meaning that it sits atop a mountain. Which means that from the coast of France, I had to gain 600 feet of elevation on my bicycle to reach it. Which wasn't really all that difficult, except that I was now carrying the added weight of two kilos of ochre, along with two film canisters filled with who knew what, all of which I wore in a fanny pack during my ride to Saint Paul, and then back to Cannes. Poor planning.


Getting Uranium into the United States

Safely back at my hotel room in Cannes, I now had to decide what to do with my "uranium." If it really was uranium, and it was detected in my checked baggage, I would probably be in big trouble. If I put it in my carry-on bag, and it was radioactive, it would be detected for sure. Airport x-ray machines work by bouncing radiation to a detector - if something being scanned was already emitting its own radiation, it would look very "hot," and would probably be pretty alarming to a screener. Carrying the two film canisters through airport security in my pockets was a possibly - but who wants to carry radioactive material, if that's what it was, on their body?


Ultimately, I decided to mail the film canisters from France to myself. Although not without its own set of risks, mailing proved to be simple and fast, and it worked.


Center: one of my canisters of Uranium Oxide. Left: Ocre Terre de la Puisaye
(ochre from the town of Puisaye). Right: Gres de Thiviers, Epuise
(Ocre from the town of Thiviers. "Epuise" means "exhausted" --
the mine has pinched out, and is no longer in production).

Determining Just What I Had

I was pretty excited when my package from France, unaccompanied by any members of Homeland Security, arrived in my mailbox. I immediately got on the phone and tried to find someone who could analyze what I had. After about forty-five minutes on the phone, talking to various departments at the local big-box university and to state and local agencies, I finally got hold of exactly the right person for the task: Ruben Cortez, Radiation Safety Officer, Environmental and Consumer Safety Section, Texas Department of State Health Services.


Ruben was extremely gracious and helpful. He placed a very sensitive Geiger counter next to my package and - lo and behold! - it started clicking like crazy. "You've sure got something there." He then scanned my still unopened package from France with a very sophisticated machine that is able to read specific isotope signatures. My package contained uranium 235 and uranium 238. Monsieur Collet had given me the real thing - yellowcake uranium!


It turns out that uranium is fairly ubiquitous in our world, and that we are surrounded by sources of low-level radiation. I'm still not exactly sure just what it is that I have, but it seems to be legal for me to posses it. It isn't exactly "depleted" uranium, but it certainly isn't enriched uranium either. Mr. Cortez informed me that my uranium isn't a great radiation hazard - in fact he showed me a sample of the same stuff in a glass amphora that he keeps in his office. The much greater danger from yellowcake uranium comes from breathing or ingesting it. Yellowcake is a heavy metal, and eating 20 milligrams of it, the equivalent of several sprinkles of salt on one's meal, will cause death. Of course, the same can be said for a lot of other heavy metals that ceramic artists routinely use such as barium, cobalt and manganese.


Historic crystalline-glazed porcelain by Gilbert
Metenier, circa 1910-30. The yellow bottle on the
right is colored with uranium oxide.

I'll also mention that yellowcake can be legally purchased in the U.S., and that it is fairly inexpensive, about $10 a pound. The trick is getting licensed to handle it. To see the hoops that one has to jump through to obtain a license for purchase, take a look at reading-rm/doc-collections/cfr/part034/part034- 0013.html . Your average potter is NOT going to get a license.


Was It Worth It?


Coincidentally, there just happened to be a uranium oxide colored, crystalline-glazed bottle at Crystallines 2005. It was included in a display of historic crystalline-glazed porcelain by Gilbert Metenier. Monsieur Metenier was a member of the French arts and crafts studio movement.


In Peter Ilsley's book, Macro-Crystalline Glazes, the Challenge of Crystals, there are photos of some unbelievable Royal Copenhagen vases dating from 1900, that I have always believed must be colored with uranium.


Crystalline Glazer Donald R. Holloway, of Monroe, Louisiana, has done a great deal of work with uranium oxide. These are the best pictures that I have of his work.


So What's Next?

Stay tuned. I believe that I have enough uranium oxide to produce between twentyfive and fifty pieces, depending on their size.


Royal Copenhagen crystalline-glazed vase, circa
1900. Likely colored with uranium oxide.

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Thanks for letting me share!

William Melstrom

Addendum: Depleted Uranium Oxide and Safety

Questions have arisen regarding the safety and wisdom of using uranium as a glaze ingredient. I do not endorse the use of uranium as a glaze ingredient in any way.

According to Ruben Cortez, Radiation Safety Officer, Environmental and Consumer Safety Section, Texas Department of State Health Services, depleted uranium oxide is not a great radiation hazard - in fact he showed me a sample of depleted uranium oxide in a glass amphora that he keeps in his office. Depleted uranium oxide makes up a very small percentage of my uranium glaze recipe. After firing, this small amount of depleted uranium is "trapped" in the vitreous glass glaze. I use my uranium glaze only on decorative vases, not on work that is likely to be used for serving food. The word "URANIUM" is clearly incised onto the bottoms of all work that I make which contains depleted uranium oxide. Uranium is ubiquitous, we are surrounded by minute quantities of it which we breathe in and ingest daily, and which we eliminate from our bodies vie our feces and urine daily.
Here is a short list of links to websites that address the issue of safety and the use of depleted uranium oxide, along with a few, brief, relevant excerpts:
Uranium is commonly found in very small amounts in rocks, soil, water, plants, and animals (including humans). Depleted uranium is used in helicopters and airplanes as counterweights on certain wing parts. Some lighting fixtures utilize uranium. A person can be exposed to uranium by inhaling dust in air, or ingesting water and food. The general population is exposed to uranium primarily through food and water; the average daily intake of uranium from food ranges from 0.07 to 1.1 micrograms per day.
Depleted uranium is also used in a number of civilian applications, generally where a high density weight is needed. Such applications include sailboat keels, as counterweights and sinker bars in oil drills, gyroscope rotors, and in other places where there is a need to place a weight that occupies as little space as possible. Aircraft may also contain depleted uranium counterweights (a Boeing 747 may contain 400-1,500kg). However there is some controversy about its use in this application because of concern about the uranium entering the environment should the aircraft crash, particularly as the metal is pyrophoric. This was highlighted by the collision of two Boeing 747s at Tenerife Airport in 1977 when the resulting fire consumed 3000kg of the material. Consequently its use has been phased out in many newer aircraft, for example both Boeing and McDonnell-Douglas discontinued using DU counterweights in the 1980s. An unexpected application is in Formula 1 racing cars. The rules state a minimum weight of 600kg but builders strive to get the weight as low as possible and then bring it up to the 600kg mark by placing depleted uranium where needed to achieve a better balance.

Depleted uranium is 40 percent less radioactive than the natural uranium that we all eat, drink, and breathe daily.
Each of us ingests and inhales natural uranium every day from our air, water, food, and soil. The amount varies depending on the amount found where you live, and where the food you eat and the water you drink are produced. Consequently, each of us has some uranium in our body, and we eliminate some in our urine every day.
Uranium in our Bodies
Source.................................................Amount (micrograms*)
Average Daily Intake: Liquid.................2.1
Average Daily Intake: Food (U.S.)........0.9 - 1.5
Average Daily Intake: Inhalation.............0.0010 - 0.010
Average Uranium (total) in the body.......2 - 62
*Note: 1 microgram = 0.000000035 ounces
RAND, 1999. "(N)o evidence is documented in the literature of cancer or any other negative health effect related to the radiation received from exposure to natural uranium, whether inhaled or ingested, even at very high doses." Department of Health and Human Services, Agency for Toxic Substances and Disease Registry (ATSDR) in 1999 Toxicological Profile for Uranium. "No human cancer of any type has ever been seen as a result of exposure to natural or depleted uranium."
"URANIUM and CERAMICS" by Edouard Bastarache.
"Uranium, fluorescent and Vaseline Glass." Boyd Glass and Fenton Art Glass are two USA companies that produce uranium glass items today. Tests conducted by Jay Glickman (reported in his book "Yellow-Green Vaseline: A Guide to the Magic Glass) and separate tests by Frank Fenton, of Fenton Glass, have shown that the radiation levels from even large quantities of uranium glass at close quarters are no more harmful than those associated with television sets or microwave ovens.
Crystalline glaze artist Phil Morgan's application to aquire depleted uranium oxide.
There are plenty of "scare" sites dealing with depleted uranium oxide on the World Wide Web. Please educate yourself. Remember that radiation is not harmful per se. There are different types of radiation. Radiation treatments are used to treat some types of cancer and have saved lives. Let me stress that I do not endorse the use of uranium as a glaze ingredient in any way. Depleted uranium is a heavy metal, and is highly toxic when ingested. People working with uranium should educate themselves to the dangers involved. Ceramists using uranium should, at the very least, exercise the same precautions that they use when handling lead, barium or manganese, and should wear respirators and hand protection at all times. Uranium-containing glazes should never be used on functional ware.