NC Art Pottery Orange-Red Glazes -- Chrome? Uranium? A Touch Of Gold Dust, Perhaps?

by Jay Henderson

Did North Carolina potteries use uranium oxide glazes in the pre-WWII art pottery era? For a long time many students of North Carolina art pottery have held that they did, but this author has been unable to find any verifiable example of such a glaze. There are many examples of chromium oxide red-orange glazes, of course, and the colors of these glazes can be very similar. However, chromium oxide is not radioactive -- uranium oxide is, even in a glaze -- and chromium oxide does not glow under ultraviolet light, while uranium oxide glazes often do fluoresce in the presence of UV light.

About a year ago, North Carolina pottery collector Peg Wiebe mentioned that she had used an ultraviolet light on pottery -- this can be used to detect repairs, for example. Intrigued, I did some reading and found that UV light can induce fluorescence in certain minerals, including uranium oxide. Cazart! A means to test the assumption that North Carolina potters used uranium oxide glazes! However, neither Peg Wiebe nor I have, so far, found a pre-WWII orange or red glaze which responds to UV light.

So why did most North Carolina potteries discontinue chrome red glazes after WWII? One assumption had been that the orange-red glazes couldn't be made once the U. S. government monopolized the supply of uranium oxide during WWII. Not so, it appears. Part of he answer may be changes in consumer preferences -- the 1940s and 1950s saw a shift to pastels and the 1960s a shift to rustic glazes. Probably more important was the necessity to adopt economies of scale in the post-war era in order to survive against competition from factory-made and imported wares.

Chrome red glazes are restricted to earthenware fired to Cone 08 or below, with Cone 010 being typical, and a finishing temperature of no more than 1750 degrees F. Above that temperature, chromium oxide changes to a green color in a lead glaze. (Exposure to a reduction atmosphere during firing will also turn the glaze black.) This firing range is much lower than the North Carolina potters used for earthenware and far below the Cone 3 (more or less) temperatures achieved at the J. B. Cole and A. R. Cole operations. Thus, chrome red pottery would have to be fired by the entire kilnload -- and that became economically impracticable as consumer tastes changed.

THE GOLD DUST MYTH

One persistent myth is that J. B. Cole Pottery used gold dust in its pre-WWII chrome red glazes. I can identify the source of this myth -- it came from Waymon Cole, who had an impish sense of humor and foisted the gold-dust story off on me in my gullible youth. Not until four decades later, when I began to take pottery classes at a local community college and studied clay and glazes, did I realize that Waymon had been pulling my leg. Gold is used in ceramics, but its use is very limited, partly by its volatility when heated to high temperatures and partly by its expense.

Consider this: in the late 1920s, the price of gold ran $21 per ounce -- about $260 per ounce in today's money. J. B. Cole's Pottery mixed its glazes in huge lots -- clawfoot bathtubs, for example. The cost of mixing in enough gold dust to have an effect on the finished glaze would have been prohibitive. Granted, chromium oxide isn't cheap, but at about two bits to a buck a pound, it was much more affordable than gold dust.

I cannot, of course, eliminate either possibility -- that some NC art pottery glazes contained either uranium oxide or gold dust. But in the absence of evidence, one must presume that neither was used. If anyone finds a vintage NC art pottery glaze that fluoresces under black light -- please send me pictures!

THE HISTORY OF URANIUM GLAZES

Uranium oxide added to a lead-fluxed glaze produces a spectrum of bright, attractive colors ranging from ivory, yellow, and orange to deep orange-red, depending on the amount added and the other characteristics of the glaze composition. The dark orange-red versions of uranium glazes are often spotted or streaked with black or cream-colored areas.

The glazes were very popular during the pre-WWII art pottery era and remain popular with collectors today - - good examples bring premium prices, especially for deep red pieces, even though this glaze is among the most available from that time. While uranium oxide has recently become available to potters once more, restrictions on the use of lead are likely to preclude the return of the lead-uranium glazes found on vintage art pottery pieces.

Although uranium glazes had been developed long ago (written formulas survive from the mid-19th century), they were not widely used until the 1920s. Following the discovery of radium by Marie and Pierre Curie in 1898, pitchblende was mined and processed for its very small radium content (about one gram of radium per three tons of pitchblende), resulting in the production of many hundreds of thousands of tons of uranium oxide compounds as by-products. These by-products were sold inexpensively for various uses, including glass and ceramics, until World War II. "Vaseline glass" made during the Depression era uses uranium oxide to produce its green hue.

Uranium pottery glazes were used commercially until 1943, when the supply of uranium oxide was monopolized by the United States government during the development of the atomic bomb. A familiar example is the "Fiesta" line produced beginning in 1936 by the Homer Laughlin Company of West Virginia, which used uranium oxide to make Fiesta Red and Fiesta Ivory glazes. The J. A. Bauer Pottery Co. in California reportedly used 450 pounds of sodium uranate per week during the 1930s.

The color of the finished glaze is determined by the amount of uranium oxide added to the base. Sodium uranate was the most common form of the oxide used by potteries. Because uranium oxide remains in a refractory state and does not contribute to the fluxing of the glaze, it can be added in relatively large amounts. Depending on the other constituents, lead-fluxed glazes would be colored yellow by additions of 5% to 10% sodium uranate by weight; orange by additions of 10% to 15%; and red by additions of 15% to 20%.

Finally, uranium oxide remains radioactive even when melted in a glaze. It can be detected with a real Geiger counter (not one of the yellow civil defense models; those are not real Geiger counters) and sometimes by the use of ultraviolet light. The response to the Geiger counter or "black light" is weakest for ivory and yellow versions, and strongest for the deep orange-red glazes. (Note that not all uranium glazes respond to a "black light.")

Is vintage uranium-glazed art pottery safe? Probably, as long as you don't use it to decant acidic substances such as orange juice, which will leach both lead and uranium from the glaze. A few pieces of uranium-glazed pottery in a collection are unlikely to be hazardous, although a large number in an unvented room might be; see the References for articles on this subject. Ironically, the most radioactive ware was Fiesta Red made by Homer Laughlin from 1959 to 1972, using depleted uranium which the Atomic Energy Commission had made available for commercial use; depleted uranium is far more radioactive and toxic than sodium uranate and resulted in glazes that produced radon.

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Copyright 2010 by J. R. Henderson. This article was originally published in Backcountry Notes, which provides references to source articles. Reprinted by permission.

C. C. Cole "Tourist" Pottery

C. C. Cole "Tourist" Pottery, by Jay Henderson

C. C. Cole "tourist" pottery is the secret sin of many collectors and admirers of North Carolina art pottery. Often consigned to second-class status - - as if the great bulk of North Carolina pottery of the era wasn't sold to tourists - - these colorful and usually multi-colored honey jugs, cider jugs, vases, and cream-and-sugar sets are works of artisanship in their own right.

All of the Piedmont pottery shops made "tourist" pottery to a certain extent, but this was the main product of Charlie Cole's operation. C. C. Cole Pottery opened for business in 1938 and closed in 1971; in between those points, it turned out millions of "tourist" pottery items. Many of these were wholesaled to companies like Stuckey's, which filled them with honey or syrup for sale on the pre-Interstate Highway rest stops. Like other North Carolina art pottery shops, C. C. Cole Pottery also made small pieces for wholesaling to the soap-and-candle concerns, such as Carolina Soap & Candle Makers and Tar Heel Candle Co.

Charlie Cole had been a potter in his own right but had quit turning pots after he lost a finger following a snake bite. (A picture of a Charlie Cole piece can be seen on Michael Mahan's blog.) But Charlie Cole's children Thurston Cole and Dorothy Cole Auman were among the best production turners in the business. Although they occasionally made large pieces, both Thurston and Dorothy concentrated on making large quantities of small wares, particularly the polychrome-glazed honey jugs for which C. C. Cole Pottery is known.

The polychrome glazes are not unique to C. C. Cole Pottery, but they are characteristic of its wares. C. C. Cole polychrome-glazed pieces first were dipped in a white body glaze; other colors were dribbled around the body; then the top was dipped in yet another color. Four-color glazes are typical, but there are many pieces with three-color glazes and some with a body glaze and a top glaze. There are pots glazed in single colors, including both colored lead-fluxed glazes and lead-rutile matte glazes.

The finished appearance of the multicolored glazes can vary greatly, depending on the degree of heat applied during the final burning of the ware. The glazes on some early pieces are barely vitrified; other pots have over-fired glazes which have run together. Lead-rutile glazes have a matte finish at normal earthenware temperatures but take on a high-gloss, variegated surface at higher heat levels. Part of the charm of C. C. Cole pottery is the seemingly-endless variety of colors and glaze melts available.

The great majority of C. C. Cole pieces are unmarked. For a time during the 1950s, some pots were marked with a pair of stamps reading "C. C. Cole" and "Seagrove, N.C." These are relatively scarce. Charlie Cole also had a logo which contained the name "Dixie Craft Pottery," but the logo was used only on advertising materials and was never stamped on the pots. The "Dixie Craft Pottery" name likely derived from the Carolina Craft Pottery, which Charlie Cole and his brother Everett operated in Wake County from 1927 until 1933.

Thurston Cole was still young when he died in 1966. His premature passing was a loss not only to the C. C. Cole shop but to the whole North Carolina art pottery genre. When not engaged in producing honey jugs, Thurston made large pieces; some of his big floor vases are truly spectacular. Had he lived to see the Seagrove pottery revival, there undoubtedly would have been more of these. Two fine examples of Thurston Cole floor vases are reproduced in Perry (ed.), North Carolina Pottery, at pages 63 and 76.

Charlie Cole died in 1966. Both Dorothy and Walter Auman continued to work at C. C. Cole Pottery, turning and glazing pots, until that shop closed. During its thirty-plus years in operation, C. C. Cole Pottery produced a huge volume of pottery; the honey and cider jugs alone certainly numbered more than 5 million, and maybe double that. In one perspective, Thurston Cole produced more pots in a year than most studio potters make in a lifetime. Because they were used to sell honey and syrup, many of these were damaged or discarded, but the shop's output was so high that pieces remain available on the secondary market, turning up at yard sales and flea markets on a regular basis.

For a longer version of this article, click HERE.

To see a gallery of C. C. Cole tourist pottery, click HERE.

Text and images copyright © 2009 by Jay Henderson. All rights reserved.

The JB Cole 1940 Catalog

by Jay Henderson

One of the nicer finds for any collector or student of vintage North Carolina art pottery is a copy of the 1940 J. B. Cole's Pottery Catalogue.[1] I am fortunate to own an original copy of this well-made, paperback booklet. There is also a reprint, issued in 1997 by Holly Hill Pottery with some added material, which occasionally crops up. The reprint is well done but suffers some loss of detail in the process of reproducing the 1940 version.

The J. B. Cole catalog itself is not dated, but it is typically found with a folded-insert price list dated June 1st, 1940. If there was an earlier or later price list, no sample has surfaced. The price list, by the way, should be read as a curiosity; otherwise, it may drive you mad to realize that a 16-inch Waymon Cole rat-tail-handled floor vase, which would sell for several hundred dollars today, went for $1.25 in 1940. If only . . . .

The catalog features monochrome photographs of 526 pieces and sets pottery of all descriptions, ranging in size from 1-3/4" miniatures made by Nell Graves to a yard-high Rebecca pitcher by Waymon Cole. Each piece or set is separately identified by a designator like the following examples: W 80 - 5"; N 235 - 3-1/2"; G 278 - 11"; or B 513 - 7". The letter W indicates Waymon Cole; the letter N indicates Nell Cole Graves; the letter G indicates Phil Graves; and the letter B indicates Bascom King, in each case identifying the person who would turn the piece or set. The letter is followed by a serial number, and then a hyphen and a number indicating the height of the finished piece in inches.

The serial numbers run from 1 through 524; in two cases, errors were made in the numbering and a letter "A" was added before the designator (AB 422 and AB 453). The serial numbers are grouped by potter, with a few exceptions. The numbers for Waymon Cole begin at 1 and continue through 177; however, four Nell Graves pieces were photographed out of order (N 47, N 48, N 72, N 120). There are other out-of-order pieces here and there. When these are accounted for, the number of pieces and sets by potter runs as follows: Waymon Cole, 174; Nell Graves, 86; Phil Graves, 153; and Bascom King, 113. I am convinced that some errors were not caught and there are a few pieces which may be mis-identified; comparing W 93 - 7-1/2" with the very similar N 241 - 3-1/2", for example, leads me to believe that the un-Waymonlike 93 piece was actually turned by Nell.

The high number of pieces attributed to Waymon Cole appears to have been the result of his taking over certain forms formerly turned by his father, J. B. Cole, who had quit turning before 1940. For example, known surviving pieces of W 31 - 15-1/2" are reliably attributed to J. B. Cole. A comparison of one of the J. B. Cole pieces with a W 31 turned by Waymon reveals characteristic differences, such as the difference in handle formation.

The lower number of pieces listed for Nell is probably related to the size of her wares. Because Nell turned many small and miniature pieces, her father modified her wheel to make it more suitable for that specialty. A riser was added to the wheelhead (this is shown in the photograph of Nell in the catalog, reproduced at the end of this article) and Nell's wheel was belt-driven by an electric motor, powered by a generator. These modifications were useful for making 3-1/2 inch pitchers and vases, but at the same time limited the maximum width of the base of a piece and probably also the weight of the ball of clay that could be used on the modified wheelhead.

The 1940 Catalogue identification system is very helpful for identifying the work of the J. B. Cole potters.[2] While many pieces are easy to pin down, such as the massive Waymon Cole floor vases and the tiny Nell Cole items, others are more difficult. Knowing the approximate height of the finished piece is very helpful. The picture of the form, the height, and the designation of the potter assist not only in distinguishing among pieces made at J. B. Cole's Pottery but also among the many similar pieces made by competitors. The J. B. Cole potters made pots to sell, and some sold more than others - - and therefore, more examples of the popular wares survived to the present time. Some forms, like W 80, W 157, W 177, N 183, N 230, G 354, G 395, B 466 and B 516, come up for sale frequently and are familiar to collectors and students. Other forms are rare and the catalog is invaluable for confirmation of their authenticity.

Also useful is the catalog's listing of colors: "yellow, white, rose, dark blue, Alice blue, periwinkle blue, turquoise, blue-green, enamel-green, peacock blue, blue-and-white, orange, rust, and antique." As with the forms, some of these colors were popular and some were not. Alice blue (a pale, bluish-gray) seems to be rare, while orange (usually called "chrome red") is relatively common.

Neither the forms in the catalog or the glaze colors should be considered a complete listing. Very early pieces were finished with commercial glazes, and new forms and glazes were developed over time, with some shapes being dropped and new ones being added, in addition to changes in the making of established forms. A major example of this is the Waymon Cole signature piece, the Aladdin's Lamp teapot; it had not been developed in 1940, although the bowl-vase on which it was based is in the catalog (W 6 - 5"). The 1940 Catalogue is nonetheless a valuable guidebook for pre-WWII J. B. Cole Pottery wares.

One should exercise caution when identifying post-WWII J. B. Cole pieces. The fact that a form appears in the 1940 Catalogue does not mean that it was made before World War II; other characteristics must be taken into account. Having a copy of the 1940 Catalogue won't make you an expert. Inspecting many pieces of J. B. Cole's Pottery wares is the only way to achieve sufficient knowledge.

NOTES: [1] The name "J. B. Cole's Pottery" was used until J. B. Cole died; Waymon Cole and Nell Graves bought out the heirship interests of their siblings and changed the name to "J. B. Cole Pottery." The spelling "Catalogue" is used in the 1940 booklet.

[2] There are smaller catalogs, one known as the 1932 J. B. Cole catalog and another known for C. C. Cole; these are very hard to come by and as far as I know have not been reprinted.

This article originally appeared in Backcountry Notes.

Copyright © 2008 by Jay Henderson.