The Mystery and Allure of Cobalt Sea Glass

Updated from version published in spring 2014 edition of Shorelines Newsletter 

Ellie Z. Mercier

 

Sea glass collectors can certainly relate to the jubilant sensation that transpires when striking gold. Of course, not the sought after nuggets that lured settlers west during the Gold Rush of 1849, yet smoothly tumbled specimens of the finest quality, which actually have no resemblance to gold whatsoever but are dressed in the magnificently rich hue of cobalt blue.

Many enthusiasts would likely agree that discovering prized shards of ruby red, yellow, and purple – and especially those boasting coats of orange – are surely hobby-related milestones worth writing home about. However, although true blue finds are generally more plentiful than the shades ranked as most scarce, few collectors can resist the mysterious allure of cobalt blue sea glass.

Detecting glimpses of well-worn cornflower or royal blue gems ashore may generate well-deserved shrieks of delight on behalf of some beachcombers, while others may experience a stunned silence. Yet despite the differing external reactions to such feats, collectors are often left to ponder the magical significance of the cherished shade.

Represented as the first element in the ninth column of the periodic table, cobalt possesses an atomic number of 27 and is recognized by the symbol Co. The mineral was formally discovered in 1735 by Swedish chemist George Brand, who dispelled the myth that the element Bismuth was responsible for the rich blue color of glass. However, coba

lt compounds were used for thousands of years before Brand isolated the element. Scientists have traced the use of cobalt back to the ruins of the ancient city of Pompeii and to early civilizations of Ancient China, and the mineral was also used in Egyptian art and Persian pottery. Although prior to the 1940s, cobalt was used sparingly due to the limited quantity, the expense, and the difficulty to extract the mineral. Modern day collectors often associate the shade with luminous blue medicine bottles and cosmetic jars produced during the early to mid-twentieth century.

However, cobalt’s use as a coloring agent is not limited to glass, jewelry and ceramics; the compound is also used as a pigment for paint, ink and even cosmetics. Other applications of cobalt include the production of rechargeable batteries and the electroplating of cutlery and jewelry. Rather than an element found in nature, cobalt is a hard yet brittle mineral contained in the Earth’s crust and is a byproduct of the mining of other metals, including nickel, copper, silver, lead and iron. In its natural state, the color is a bluish-white shade, similar to gray. Cobalt salts are actually the source of the brilliant and permanent rich hue associated with the mineral. The majority of cobalt is mined in Africa, particularly in the Democratic Republic of Congo (or Zaire, prior to 1997), which extracts close to forty-percent of the world’s supply annually. Other sources are found in Canada, Brazil, Russia, China and Morocco. Also, researchers believe there is a vast source of cobalt contained in the ocean’s floor, although scientists currently lack the technology to extract the element. Interestingly, studies conducted by the United States Geological Survey conclude that cobalt likely exists in the shallow waters of the Hawaiian Islands (USGS).

Ironically, among the many interesting facts about cobalt is the mysterious nature of how the color’s name originated. Long ago, superstitious German silver miners believed that malicious spirits were affecting their health as well as stealing silver ore from the mines, and they referred to these spirits as kobalt, a derivative of kobold, which is German for goblin. Other fascinating facts surrounding the element include artist John Varley’s presumption that cobalt is an ideal substitution for the shade of ultramarine blue, which was widely used for painting skies. Another artist, Maxfield Parrish, was so well known for his superior cobalt blue sky-scape paintings that the hue is sometimes referred to as Parrish blue. Cobalt was also the primary pigment used in notable blue and white Chinese porcelain, originally produced in the late eighth or ninth century. Furthermore, cobalt is used to illuminate the cornea of the eye to detect corneal scratches and is used in the production of magnets, and Radioactive Cobalt is used to treat cancer. And oddly enough, cobalt is added to the diet of sheep in order to prevent disease and improve the quality of their wool.

The outward reactions of those fortunate enough to experience such a hobby-related milestone as striking gold – or rather, witness sudden brilliant glimpses of blue jump out from the sandy canvases before them – may differ significantly, but few sea glass collectors can resist the powerful allure of cobalt treasures, which in many aspects, are truly gifts of Mother Nature.

Photos: Ellie Mercier

  • Ellie found the frosty marble in the Abacos (her first marble find & she remembers that she was extra excited because Richard LaMotte shared that cobalt marbles are more rare than red marbles).
  • The bottle is from Ellie’s bottle collection – She also collects antique bottles.
  • Ellie found the jar lid in the Chesapeake Bay (almost a decade ago)
  • Yet most interesting is the image of the large cobalt shards, which Ellie found following the 2009 festival in Lake Erie…One of her customers took me combing along the river in nearby Conneaut, Ohio, where much slag glass was discarded in the 1960s by the GE Light Bulb Base Plant (these are huge, and the hue is extremely vibrant, alike bright violet).

Beachcombing Stoneware Sea Pottery

by Connor O’Brien

The majority of sea glass originates from mass produced utilitarian vessels, while tableware and art glass are less common sources. The same can be said about sea pottery. Yet due to the immense variety of ceramics, identifying sea worn fragments can be particularly challenging. A good way to start is by classifying shards into one of three categories: earthenware, stoneware, or porcelain. Ceramics are grouped into these categories based on the density and firing temperature of the clay. The clay mixture and body of a ceramic is referred to as paste, whereas the surface coating is known as glaze. Grouping ceramics by paste type is the first step in identifying the origin of a shard, and learning to distinguish different pastes and glazes is crucial to making accurate identifications. (Figure 1)

Figure 1. A small representation of earthenware, stoneware and porcelain. All three types are variable in color, appearance, and texture, so the best way to identify them is to learn the feeling of the differences simply by handling them.
Top row: Red earthenware fragments, brick and terracotta. The color of earthenware can range from cream white to red, dark gray or tan, depending on minerals in the clay used. It is distinguished from stoneware and porcelain by its relatively low firing temperature, porous and less dense paste.
Middle row: stoneware jug fragments. Stoneware is nonporous, hard and compact, fine textured but not glassy like porcelain. It requires a medium to high firing temperature but does not need glaze to be watertight. However stoneware is often glazed with salt or decorative slip glazes. Slip glazes are glazes comprised of clay in water, applied by dipping or washing the ceramic vessel.
Bottom row: Porcelain fragments distinguishable by the very hard dense body, vitreous nature and white color. Porcelain can be glazed and decorated in a variety of ways.

Investigating traditional and regionally relevant ceramics is a great place to start when studying sea pottery. Understanding the history of production is also very helpful when it comes to identifying and dating shards. For beachcombers in North America, especially those on the shores of the Great Lakes and east coast, stoneware is a common source of sea pottery because it was once popular and locally produced. With basic knowledge of vessel shapes and glaze types it is possible to know the origins of these stoneware fragments, despite the fact that they are highly altered from their original form. An immense variety of products were available in stoneware, the most common being jugs and pots. Learning to recognize the characteristics of these forms is another important part of identifying sea pottery. (Figures 2-5)

Figure 2. Stoneware sea pottery with distinct features.
Top Row: Decorative cobalt glaze applied to an incised design. Decorative cobalt glaze applied with a sponge, known as spongeware. Decorative cobalt glaze applied to a sculpted pattern. Decorative dot band applied with a rolling tool.
Middle Row: Slip glazed shard exhibiting pop out, a defect formed during the firing process. Slip glazed shard from a jug neck, the curve of the neck influences how the glaze is weathered. Slip glazed shard with concentric lines, small surface ripples left by the potter influence the exposure of glaze to abrasive forces.
Bottom Row: Dark colored Albany type slip glaze, the use of this glaze can date shards as early as 1860. Boarder between Albany type and Bristol type glazes, use of both glaze types dates shards before 1915. Light colored Bristol type glaze, use on both the interior and exterior dates shards after 1915. Note that these dates are approximate generalizations not strict limits.

 

Figure 3. Stoneware jugs are arguably the most common source of stoneware sea pottery. These containers were made in many capacities and styles, and used for storing and selling liquids in bulk; they commonly held molasses, honey, syrup, vinegar, liquor, cooking wine, and chemicals. Similar to glass bottles, stoneware jugs have many features that can provide identifying information, such as the handle, shoulder, closure, and base. One jug may produce dozens or even hundreds of sea pottery shards, and a single shard can be used to make an accurate identification. Stoneware shards can also be confidently matched by paying close attention to paste and glaze. The shards pictured here undoubtedly originate from the same jug. Although found at different times, each occurred in the same area of the beach and have a distinct feel and appearance that suggests a shared origin.

 

Figure 4. The mark of a twisted wire pulled in a loop in order to cut the vessel from the wheel. Subtle markings such as this can be used as clues to gain information about the shards origins, as well as the processes used to create it.

 

Figure 5: Squeezed clay lines resulting from clay being compressed into a mold, an indication that the original vessel of this shard was made by mold.

Stoneware ceramics in North America began with immigrants from Germany, England, and France who brought the craft over seas in the 17th and 18th centuries. Colonists continued to import English and German stoneware well into the 19th century, yet over many generations of master and apprentice, ceramic artisans blended old world techniques and styles to develop a distinctively American variety of stoneware. The earliest American stoneware was made from scratch in small batches and distributed locally. These ceramics were often plainly salt glazed, crudely shaped, and occasionally decorated with cobalt motifs. The nature of ceramics allowed for artistic expression, stoneware creations were individually handmade and often intentionally embellished with a personal touch. For these reasons collectors regard 17th and 18th century American stoneware as a folk art. The uniqueness and relative scarcity of these vessels make them a rare source of sea pottery that is difficult to trace. (Figure 6)

Figure 6. The appearance of plain salt glazing is often compared to the texture of an orange peal. The color of salt glazing is variable but commonly brown or gray. Plain salt glazing typically dates shards prior to the 20th century. This shard originates from a salt glazed ceramic water pipe, which was a common form of plumbing and drainage throughout the 19th century.

Potters’ firms and their networks grew alongside the development and expansion of the United States. By the 19th century utilitarian stoneware was an essential part of everyday life and potteries were established all across the country. Potters were able to obtain better and more consistent materials, improve their shaping techniques, as well as distribute their wares beyond local communities. These advancements, paired with the increasing demand for American stoneware, lead to a transition from small family businesses to unified potters’ firms. Individuals who specialized in specific tasks of an assembly line began to replace the tradition of master and apprentice. By the turn of the 19th century, the demands for American stoneware were met by the mass production of simple and uniformly slip glazed vessels commonly known today as crocks or crockery. (Figure 7)

Figure 7. Stoneware vessels typical of the late 19th century and early 20th century. Markings such as words, stamps, and capacity numbers can be used to help make precise identifications. Drips from the slip glazing process are indicative of the dipping used to apply the glaze. The combination of Albany type interior and upper exterior with Bristol type on the bottom exterior was a fashionable design that declined in popularity after 1915.

The quantity and consistency of mass produced vessels is what makes them common and identifiable. Glaze type can be used to date stoneware to a relative era (Figure 2). The iconic two-toned stoneware with brown Albany type glaze on top and white Bristol type glaze on the bottom began to replace plain salt glazed stoneware during the mid 19th and early 20th century. By the 1920’s, stoneware glazed entirely in white Bristol glaze was favored for the sanitary appearance and easy to clean surface. The great depression effectively ended the era of American stoneware, though it has been continually produced, it can be assumed that most fragments of stoneware sea pottery are near or over a century old. With basic knowledge of these ceramics even ambiguous shards are relatively identifiable. When dating sea found shards, the context and history of the beach is equally important as the history of the fragment and may help provide a more accurate identification. A perfect way to display these beachcombed shards is to store them in a stoneware vessel, such as an open container. (Figure 8)

Figure 8. A perfect way to display stoneware sea pottery is to store it inside a stoneware container. Adding a false bottom using cardboard and covering it with a thin layer of shards is an easy way to make an attractive display. Stoneware pots come in many forms and sizes and also make a good depository for storing shards in bulk.

 

Works Cited: Greer, Georgeanna H., Chris Williams, and Tina Griesenbeck. American Stonewares: The Art and Craft of Utilitarian Potters. Exton: Schifftler, 1981. Print.

Connor O’Brien lives in Maine and is a college student and an avid sea glass and sea pottery collector.   http://www.seaglasssassociation.org

Mary McCarthy to host lecture during North American Sea Glass Festival in Ocean City, Maryland

Mary McCarthyMary McCarthy will host a lecture “Sea Glass Marbles From Around the Globe” during the 11th Annual North American Sea Glass Festival in Ocean City, Maryland on Saturday, August 27th.  Mary will share her knowledge and years of experience on sea glass collecting with you, particularly marbles along the shore of the Chesapeake Bay and its tributaries.  Sea marbles wash up on beaches around the world. Why? Were they used as ballast for ships? Did they come from the insides of bottles at bars? Or were most simply used as children’s toys, ending up in the waves after many years on beaches at play? This lecture will explore the origins and history of the different types of marbles that wash up on shorelines, and include a display of sea marbles from over 20 countries and waterways from around the globe.

Mary McCarthy is a bestselling author and lifelong journalist. Currently Senior Editor forSpliceToday.com, her writing career includes Salon.com, Washington Post, Philadelphia Inquirer, Baltimore Sun, editorial positions at regional magazines and newspaper humor columns.  She has blogged for Katie Couric and appeared on The Today Show.  She is an Adjunct Instructor for American University and an instructor for The Writer’s Center in Washington, D.C.

Mary started sea glass hunting when she moved to Maryland’s Eastern Shore in 2001. She often writes on sea glass related topics. She has spoken at the International Beachcombing Conference and Chesapeake Bay Environmental Center Sea Glass Conference, and joined NASGA this year as a commercial member. You can follow her sea glass finds in real time online at Instagram.com/marytmccarthy.

North American Sea Glass Festival, Ocean City, Maryland

Sea Glass Soiree  Friday, August 26, 2016   5pm – 9pm

Sea Glass Festival  Saturday, August 27, 2016  9am – 6pm

www.seaglassassociation.org

Richard LaMotte to host lecture during North American Sea Glass Festival in Ocean City, Maryland

Richard LaMotteRichard LaMotte will host a lecture “The Lure and Mysteries of Sea Glass” during the 11th Annual North American Sea Glass Festival in Ocean City, Maryland on Saturday, August 27th.  Richard  will share his knowledge and years  of experience on sea glass with you, accompanied by Celia Pearson’s beautiful images from his two books, Pure Sea Glass and The Lure of Sea Glass.  Richard plans to provide insight into the art of identifying unique shards and review the basic science of how sea glass is formed.  Learn why certain colors are so much harder to find than others and explore the history of sea glass.  Questions are encouraged as this lecture will serve to be a valuable exchange of information between Richard and anyone seeking to learn more about these vanishing gems.

The Lure of Sea Glass

A little bit about Richard and his latest book, The Lure of Sea Glass: Our Connection to Nature’s Gems.

Richard LaMotte, author of The Lure of Sea Glass: Our Connection to Nature’s Gems, is America’s leading authority on sea glass.  His new book, which focuses primarily on the emotional side of sea glass, was prompted by the many stories and anecdotes he has heard over the years from people who shared with him how much sea glass collecting has meant in their lives.

Since the publication of his first book, LaMotte has hosted or attended hundreds of events for sea glass collectors all over the nation.  At these events, sea glass aficionados have had an opportunity to view others’ collections and learn more about the sea glass phenomenon.  He is a former president of the North American Sea Glass Association, which annually holds a national festival for sea glass collectors and those interested in learning more about the subject.

The new book is a sequel to his classic, Pure Sea Glass: Discovering Nature’s Vanishing Gems, which was published in 2004.  That book, which has become the definitive book on the subject, helped spark the increasingly popular pastime of collecting treasures from the sea.  It earned first place in non-fiction from the Writer’s Digest 13th Annual International Self-Published Book Awards.  Since 2004, his company, Sea Glass Publishing, L.L.C., also has produced calendars, note cards, identification cards and other products featuring photographs and information about sea glass.

LaMotte and his family have collected more than 40,000 pieces of sea glass, much of it from the Chesapeake Bay, near their home in Chestertown, Maryland.

LaMotte has been interviewed in leading newspapers including The Washington Post, the Baltimore Sun, the New York Times and the Boston Globe.  His work also has been featured in magazines including Coastal Living, Parade and Delaware Beach Life.

North American Sea Glass Festival, Ocean City, Maryland

Sea Glass Soiree  Friday, August 26, 2016   5pm – 9pm

Sea Glass Festival  Saturday, August 27, 2016  9am – 6pm

www.seaglassassociation.org

 

A New Year and A New Calendar: Reserve a Date with Mother Nature

by Ellie Mercier

Photo from iloveshelling.com
Photo: iloveshelling.com

For an avid beachcomber, no day planner is complete without penciling in a few dates with Mother Nature (permanent ink is preferable). As stated in an article that appeared in a former edition of NASGA’s newsletter, Shorelines, “Ideal dates for beachcombing outings are often attributed to ‘being in the right place at the right time,’ yet enthusiasts do not have to depend solely on luck or chance to experience fruitful searches (Winter/Spring, 2013).

This article continues to focus on fluctuations in the usual volume of nautical remnants that wash ashore in a coastal area as the direct result of natural phenomena, notably recent storm activity, flooding, and the phase of the moon and state of the tide.

Tracking the phase of the moon and state of the tide, both independent of one another, as well as in unison, is not only valuable for determining potentially preferable times to beachcomb on a daily basis but can inform collectors of infrequent instances of natural phenomena that are particularly ideal for sea glass hunting. As most hobbyists are aware of, low tide, or the period when high tide begins to recede, up until the tide is at its lowest level, is much more desirable for beachcombing than during high tide, when turbulent waves pull the remnants deposited ashore back into the ocean.

Although the general difference in the magnitude of daily tides is often not particularly significant, the moon, which is the primary gravitational force that determines tidal conditions, reaches a perigee in each of its 28-day elliptical orbits, defined as the moon’s closest point of approach to the earth. At perigee, or on the specific day of each month in which the moon is closest to the earth, a heightened tidal range ensues, producing slightly more preferable conditions for beachcombing.

Additionally, twice per month, during the new moon and the full moon, the earth, sun and moon are nearly in line, a phenomenon referred to as a spring tide, which also produces an increase in the average range of tides. However, when the occurrence of a new or full moon (spring tide) coincides with the time of the month in which the moon is closest to the earth (perigee), an even greater impact on the tides results, known as a perigean spring tide, an uncommon incidence that transpires an average of three to four times annually (during the spring and fall months). Finally, and even more miraculous and infrequent than the occurrence of a perigean spring tide is the manifestation of a proxigean spring tide, a rare, unusually high tide. This very high tide results when a perigean spring tide coincides with the moon’s closest approach to the earth within an eighteenth month (or longer) period and may result in gravitational pulls so strong that the earth can experience extremely powerful high tides, often twenty to twenty-five percent higher than those that result from normal perigean spring tides (NOAA).

For those who wish to reserve a date with Mother Nature, the following charts list the dates of future perigean and proxigean spring tides through 2023 (again, using permanent ink is preferable)!

About three or four times a year, the new or full moon coincides closely in time with the perigee of the moon—the point when the moon is closest to the Earth. These occurrences are often called ‘perigean spring tides.’ The difference between ‘perigean spring tide’ and normal tidal ranges for all areas of the coast is small.  In most cases, the difference is only a couple of inches above normal spring tides.  Image and caption via NOAA.

*Tide charts compiled by Ellie Mercier, author of The Sea Glass Companion

Future Dates of Proxigean Spring Tides, 2016 – 2023*

Year  2016  2017  2018  2018  2019  2020  2021  2023
 Date Nov 14 May 26 Jan 01 Jul 13 Aug 30 Oct16 Dec 04 Jan 21
Moon** FULL NEW FULL NEW NEW NEW NEW NEW

**Conditions can be more intense during a new moon since both the Sun and the Moon are on the same side of the Earth, and with the Moon near its closest point to the Earth, the tide- making potential is highest.  Note that there are two scheduled for 2018 and none in 2022.

Future Dates of Perigean Spring Tides, 2016 – 2023* 

Year  2016 ***  2017 2018 2019 2020 2021 2022 2023
Date Nov 14 May 26

Dec 04

 

Jan 01

Jul 13

 

Feb 19

Aug 30

 

Mar 10

Apr 07

Oct 16

Dec.  04 Jun 14

Jul 13

 

Jan 21

 

 

 

***The full moon on November 14, 2016, will present the closest supermoon of the year (356,509 kilometers or 221,524 miles). What’s more, this November 14, 2016 full moon will present the moon at its closest point to Earth thus far in the 21st century (2001 to 2100), and the moon won’t come this close again until the full moon of November 25, 2034.   Information on November 14th moon via Earthsky.org

Find out more about Supermoons and Spring Tides in the coming year, visit Earthsky.org article for more info.

Visit NOAA for your area’s Tide Charts here.