The Mystique of Cobalt Blue

QUESTION: I’ve always loved objects made of cobalt blue glass. The shimmer of the deep blue glass as the sunlight filtered through it used to fascinate me as a kid. So it’s no accident that I began to collect various glass objects made of it. But even though I have a modest collection of glasses, pitchers, vases, and the like, I really don’t know much about cobalt glass. Can you please give me some background on it and perhaps tell me what’s really collectible and what isn’t?

ANSWER: Cobalt blue glass offers something for everyone. It’s color is distinctive and the variety of pieces available is great. People often associate cobalt glass with 19th and early 20th-century medicine bottles, as well as ink bottles. But the number of different objects made of it goes well beyond these two mundane things.

The addition of a small amount of cobalt to molten glass turns it a deep blue. Its use goes back thousands of years. It was the Egyptians who first developed a process to color glass using impurities found in raw materials. The Romans copied and perfected this method. In Mycenae, around 1400 B.C.E., the production of cobalt glass reached its peak. The large amount of jewelry and dishes made of cobalt blue glass found at archaeological sites show how popular it was. However, today’s collectors look to more recent times and the glass objects made during the Great Depression.

While not all cobalt glass is Depression Glass, a lot of it is. This is the most fertile area for beginning collectors because so much of it appears on the market. Besides being known as “cobalt blue,” Depression glassmakers also referred to it as Deep Blue, Dark Blue, and Ritz Blue.

Depression glass collectors particularly like to collect the Royal Lace Pattern, made by the Hazel Atlas Glass Company in the 1930s. They continued to produce this elegant pattern until 1941.

Many companies created Depression-Era cobalt glass. In the late 1920s, the Diamond Glassware Company offered cobalt blue pieces in the Victory pattern. Hazel Atlas Glass Company introduced cobalt blue glass pieces in its Aurora line, New Century, Florentine No. 1, Florentine No. 2, Hairpin, Ships and Sailboats, and Starlight. The Fenton Glass Company added cobalt blue glass to its Lincoln Inn pattern. The Moondrops and Radiance patterns by New Martinsville Glass Company provided cobalt blue pieces. Paden City Glass Company's offered cobalt blue glass pieces in their Orchid and the Peacock & Wild Rose patterns. Westmoreland Glass Company showcased cobalt blue glass in the English Hobnail line. Everyone, it seems, got in on the act.

Many companies also made beautiful cobalt blue glassware for more formal dining and entertaining. For example, Morgantown Glass Company created a line of elegant glassware in the Golf Ball pattern. The Cambridge Glass Company, on the other hand, created glassware with overlay designs.

Many companies have produced eye-catching decorative items made of cobalt blue glass. During the 1940s and 1950s, the Fenton Glass Company, of Parkersburg, West Virginia, began including cobalt blue glass pieces in its line of eggs and slippers as well as baskets. Another company that created distinctive looking slippers and other decorator pieces was the Degenhart Glass Company. Animals in every shape and size have remained popular with collectors. The Imperial Glass Co. was only one of many companies producing animals in cobalt blue.

Avon Products Inc. took advantage of the popularity of cobalt blue glass and offered a variety of items, including cruets, cologne bottles, and salt and pepper shakers, to its customers over the years, To reach those looking for more elegant items, Avon had the Fostoria Glass Company, long known for its quality glass, produce glassware in the George and Martha Washington pattern.

Lastly, some people collect cobalt blue glass kitchenware, including mixing bowls, rolling pins, refrigerator boxes, and measuring cups, produced by well-known glass manufacturers.

While some people collect cobalt glass for its value, many collect it for its beauty, especially when displayed in a window so the sunlight can shine through it, giving the room a mystical blue glow.

That's a Crock!

QUESTION: Some time ago I purchased an old crock at an antique show in my area. I believe it holds two gallons and has two hearts and the number “2" painted in blue on the front. The name Sarah Good is incised above the hearts. Can you tell me how old this crock is and what is the significance of the heart design?

ANSWER: Heart decoration was somewhat rare among crocks. Though your crock has a name incised in it isn’t unusual,  that the name is female is. This indicates that this crock may have been a wedding gift, specially made for Sarah Good. After all, a crock in the early to mid-19th century was a piece of kitchen equipment much as a set of canisters is today.

Potters made crocks of American stoneware, which they covered in an alkaline or salt glaze and often decorated using cobalt oxide to produce bright blue designs. Though people often use the term "crock" to describe this type of pottery, the word "crock" wasn’t used at the time these vessels were popular.

Stoneware is a type of pottery that’s  fired to about 1200°C to 1315°C. While it originated in the Rhineland area of Germany in the 15tth century, it became the dominant piece of houseware in America between 1780 and 1890. People relied on American Stoneware as not only a durable, decorative piece of houseware but as a safer alternative to lead-glazed earthenware. The invention of refrigeration caused its decline.

Americans began producing salt-glazed stoneware circa 1720 in Philadelphia, Pennsylvania, and Yorktown, Virginia. By the 1770s, the art of salt-glazed stoneware production had spread to many centers throughout the United States, most notably Manhattan, New York. The Remmey and Crolius families of potters would, by the turn of the 19th century, set the standard for expertly crafted and beautiful stoneware. By 1820, potters in nearly every American city produced stoneware, with those from Baltimore, Maryland, standing out for their excellent craftsmanship.

While salt-glazing is the typical glaze technique seen on American Stoneware, potters employed other glazing methods. They often dipped vessels in Albany Slip, a mixture made from a clay peculiar to the Upper Hudson Region of New York, and when fired, produced a dark brown glaze. They sometimes used this slip as a glaze to coat the inside surface of salt-glazed ware.

While decorated ware was usually adorned using cobalt oxide, American Stoneware potters used other decorative techniques. Incising, a method in which a design of flowering plants, birds, or some other decoration was cut into the leather-hard clay using a stylus, produced detailed, recessed images on the vessels. Potters usually highlighted these in cobalt. They also impressed designs into the leather-hard clay using wooden stamps. Potters occasionally substituted manganese or iron oxide for cobalt oxide to produce brown, instead of blue, decorations on their pieces.

In the last half of the 19th century, potters in New England and New York state began producing stoneware with elaborate figural designs such as deer, dogs, birds, houses, people, historical scenes and other fanciful motifs including elephants and "bathing beauties."

Most stoneware jugs had some sort of decoration on them which covered only a small area. Unlike other pottery, they weren’t decorated all over. Birds and flowers were commonly painted using cobalt-oxide glaze or incised into the surface with a stylus.

More elaborate designs featured chickens standing by a water trough or sprigs of greenery artfully handpainted with cobalt slip. Sometimes the location of the potter appeared on the side of the jar or on its base.

A crock’s decoration can often be a clue to where it was made. A two-gallon jug with a cobalt design of a sailing ship with flag atop the middle of three fasts, a light-house to the right and a group of rocks to te left, indicates that it most likely came from New England.

Potters signed a good bit of their work using their maker’s mark or sometimes incised their signatures in the surface of the jar. Many pieces can be attributed to particular makers based on the cobalt decoration, clay body, form, and such. They marked the gallon capacity of the vessels using numeral stamps or incised or cobalt oxide numbers or hash marks applied freehand.

For the last several years, stoneware prices have been climbing ever higher, especially for the high-end wares. Most stoneware crocks sell for four to six figures, depending on their maker and condition.

Collectors continue to pay premium prices for stoneware decorated with elaborate and unique motifs. Attributed to David Parr Sr. of Baltimore, a circa-1830 six-gallon jar with a cobalt design of a flower basket that covered the entire front of the vessel sold for $13,750 at auction. The back of the jar featured a flowering plant rising' from a mound of earth. The vessel had rim and base chips, as well as several cracks and still sold for a high amount.

The same auction contained a one-gallon stoneware jug showing a house, tree and fence which sold for $10,175. Stamped J. & E. Norton/Bennington, Vermont, buyers liked this circa-1855 jug not only for its cobalt decoration, but also for its small size. Salt-glazed pieces sell for especially high prices. A salt-glazed water cooler brought $10,500 at auction.