The Hedeby Harbor Purse

It was probably in the spring. Winters were cooler then, and when the waters froze, merchants could travel by sledge or by sleigh. Those who had drifted south in the fall would travel the ice roads north with wares brought in from Byzantium or the East, even as the first few hides and antlers began to trickle down from the nomadic tribes of the tundra. At a few small places scattered across northern Europe, people gathered to participate in a world of exchange that, with the Norse camp established at L’Anse aux Meadows in the year 1000, became truly global in scope. It was a good time to have a purse full of change, and a bad time to lose one.

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Artifacts from the Wikinger Museum Haithabu are currently getting packed up while the museum is renovated, offering a unique opportunity to study artifacts usually on display. This necklace of rock crystal and carnelian beads from Grave 81 (ca. 860) shows an early Viking Age appetite for Iranian or Indian imports. (Schloss Gottorf, Schleswig, DE.)

Fortunately for us, one purse did slip overboard in the bustling port of Hedeby, a harbor town located at the base of the Danish peninsula on an inlet of the Baltic Sea. The Danish kings kept a close eye on this town, with its sea routes linking in one direction through the Baltic to the Russian riverways and Central Asia, and in the opposite direction a fortified route linking to the Frankish and Frisian traders who sailed from the North Sea coast. It was probably one of these petty kings who set up the first mint at Hedeby, perhaps as early as 825. Six coins from this mint ended up in the harbor purse, along with a single coin bearing the motto “Christiana Religio” and the name of the Frankish king, Louis the Pious (r. 813–840).

This group of coins points to a purse lost sometime in the 830s, although at least one researcher has argued that, based on where the purse fell, a later date is also possible—perhaps during the course of the 900s. But the coins weren’t alone. In a compact area of 0.125 m2 (about 1 ft2), the coins were accompanied by an outstanding collection of 600 microbeads. These beads come in only four colors—white, green, blue, and black—and the beads weigh on average a mere 0.11 g (0.005 oz). Altogether, the 600 beads weigh only 68.4 g (2.4 oz)—you could find more beef in a Big Mac!

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The 600 beads of the Hedeby harbor purse come in four basic colors and six or seven standard types. Such a high level of uniformity for such minuscule objects is rarely seen before the Industrial Age. (Schloss Gottorf, Schleswig, DE.)

So the coins point to an early date and a merchant with western connections. But the placement of the purse suggests a later date and raises the possibility that these coins were old heirlooms—not currency. What do the beads say?

For the sake of space (and to leave some surprises for my dissertation!), I’ll limit myself to two observations. First, the beads are remarkably uniform. Each of the four colors gathers into a narrow range of hues, suggesting a consistent use of raw materials and glass production techniques. And the sizes and weights of the beads seem to cluster, too, although the values are very small—beads in the smallest group average only 0.04 g—so I need to assess how much measurement errors might be affecting my cluster analysis. At any rate, the uniformity of these beads shows a degree of standardization rarely seen in the pre-modern world. And the stark contrast between these mass-produced beads and the individually-made handicrafts of older towns like Ribe and Åhus suggest that these beads contributed to a rising aesthetic, and perhaps even an associated ethos, that privileged simplicity and order over variety and experiment.

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Approximately 600 small beads found in a purse with seven silver coins. Small change of the Viking Age? (Schloss Gottorf, Schleswig, DE.)

Second, these beads are all made with an identical technique using drawn glass. Workers heated the glass in a furnace, blew a bubble of air into the molten mass, stretched the hollow glass into a tube or a straw, cut the tube into discs, and melted the discs in an oven to smooth out the edges. Glassworkers were using furnaces in Hedeby by the 850s, apparently making their own glass from a Frankish recipe and using it mostly for tableware and perhaps windowpanes. But the technique used for making these beads should more likely be associated with the traditional glass production centers of the Near East: Egypt, Syria, and Iran. This gives us an interesting point of comparison for Ibn Fadlan’s famous statement (ca. 922) ridiculing Norse traders in Russia who would pay the outrageous price of a silver coin for a single Eastern bead—the merchant who lost his purse at Hedeby had seven silver coins and 600 imported beads. This suggests that if imported beads did have a monetary value when the purse was lost, it was of a different order of magnitude than the one which Ibn Fadlan describes: beads were little more than small change for at least one merchant in Hedeby harbor.

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Similar beads from throughout the settlement show more variety in color, meaning that although production techniques were consistent, access to raw materials was in flux. Could these Viking Age beads from Hedeby be a record of 9th-century upheavals in the distant Islamic world? (Schloss Gottorf, Schleswig, DE.)

For now, that’s all I can reliably offer: new bead styles reflected changing cultural values, the appearance of highly standardized beads in the harbor purse echoes written accounts that beads were being used in monetary contexts, and this particular collection of beads and coins points to business connections that traveled both east and west. In coming weeks, I’ll examine beads from mid- and late Viking-Age cemeteries in Denmark, and I’ll keep an eye out for similar beads made from cut glass. Perhaps I’ll find some buried with a coin or jewelry that can be dated by style, and I’ll have the basis for offering my own date for the harbor purse. And our understanding of the Viking Age will move one step further.


I’m still at work in Hedeby, gathering information on beads from a variety of contexts. I’ve been focusing my efforts especially on beads which are usually found in the exhibits, since these are being packed up for temporary exhibition at the Museum Sydøstdanmark in Vordingborg, DK, while the Wikinger Museum Haithabu gets a facelift. I’m especially grateful for the staff and researchers of Schloss Gottorf, who have offered me generous help and fruitful conversations.

Treasures of the Lille Karleby Hoard

This Christmas season—and especially New Years—in Denmark were like nothing I’ve ever seen, so this post is a bit of a throwback to the week before Christmas, when I was looking at beads from a hoard from Lille Karleby, about an hour west of Copenhagen. This spectacular mix of silver, bronze, glass, and stone registered only a faint beep when Søren Bagge first ran his metal detector across it in September 2015. Bagge had found a few Arabic coins in the area, but when he nicked his finger on a silver pin lodged in a silver cup, he knew he’d found something big. He contacted the nearby museum in Roskilde, and professional archaeologists were soon on the way. They built a plaster cast around the hoard so they could pull it out complete and then excavated the artifacts in a laboratory where everything could be carefully recorded and preserved. Bagge earned a finder’s fee for reporting the hoard, but for scholars and museum-goers alike, this hoard represents an invaluable treasure of the Viking Age.

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A small selection of artifacts from the recently discovered Lille Karleby hoard, currently on display at the National Museum of Denmark. Items include brooches, pendants (bottom right), silver beads (bottom left), and beads of glass and amethyst (top right). The amethyst bead might be the oldest item in this hoard, and it was probably imported to Scandinavia about 200 years before finally being buried sometime around the late 800s. Some close ups are available here. (National Museum, Copenhagen, Denmark.)

The hoard must have been a treasure for the people who buried it as well. Altogether, excavators recovered almost 400 artifacts, of which 305 were beads. Eighteen coins were included, most of which had holes in them so they could be worn as jewelry. An additional 53 artifacts are described as pendants of bronze or silver. Such an accumulation of wealth fits into the bigger picture of increasing economic prosperity and social stratification in the early middle ages. But the fact that so many of these objects were made to be worn by women testifies that male traders and raiders weren’t the only agents of change in the Viking Age.

The beads from Lille Karleby contrast strongly with other beads I’ve recently examined. These come mostly from the religious sites and central places of Uppåkra in Sweden and Sorte Muld on Bornholm. Both sites represent the old wealth of the Iron Age, with a large number of beads that can be dated to a Baltic economic boom between 400 and 600 AD. Judging from the beads and from other finds, prosperity continued at both sites until well into the 700s, with a handful of artifacts that can reliably be dated to the heart of the Viking Age. The youngest beads from these central places include some minor overlaps with the craftworking settlement at Åhus, which saw its brief peak of activity around 800 to 850.

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On the left are a selection of beads found in the settlement of Åhus from the early 800s. Very few similar beads turn up at old power centers like Uppåkra and Sorte Muld, suggesting that these places were already in decline. Only one similar bead was found in the Lille Karleby hoard (right), suggesting that its owners were only starting to accumulate their wealth at the exact same time. (L: Åhus beads from the Lund University Historical Museum, Lund, Sweden. R: Lille Karleby bead from the National Museum, Copenhagen, Denmark.)

The Lille Karleby hoard shares some of the same overlaps with the settlement at Åhus that can also be seen at Uppåkra and Sorte Muld, particularly the blue segmented beads that were so popular among Baltic craftsworkers. And while the Lille Karleby hoard has some heirloom artifacts—such as a single large amethyst bead that was a popular kind of import way back in the 600s—it lacks many of the more common pre-Viking Age beads that were scattered across Uppåkra and Sorte Muld. So although the people who buried the Lille Karleby hoard showed some interest in gaudy antiques, their beads give the strong impression of being mostly made of new wealth. When the first generations of vikings started heading west, they represented a new class of elites, and these were the things they sought to acquire.

The beads themselves give us tantalizing clues about where this new wealth came from. In particular, I counted a remarkable sixteen beads of rock crystal (clear quartz) among the 192 beads that I examined. This is a much higher percentage of rock crystal than I’ve seen at earlier sites. And the quality of rock crystal is different, too. Earlier examples are large, roughly cut, and have a yellowish hue. The Lille Karleby beads are purer, finer in size, and more carefully rounded. I’m still sorting out the research on Viking Age rock crystal, but most medieval rock crystal came from quartz mines in Iran or India. The dramatically different appearance of the old and new quartz beads is certainly one indicator that their sources were changing—trade routes with the Islamic caliphate were changing in tandem with increased viking activity. The implication, then, of the Lille Karleby hoard is that viking activity helped create a new class of Scandinavian elites capable of changing global trade networks.

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On the left is an early rock crystal bead that had been buried in a grave on Bornholm. Its yellowish hue comes from imperfections in the quartz, and it’s roughly cut with flat ends and a broad perforation. The bead on the right is from the Lille Karleby hoard. It’s a bit smaller, but it’s so smooth and so clear that you can see the dirt still inside the interior perforation. These differences in the quartz suggest different sources, and thus different trade routes. (L: Bead from Nørre Sandegård at Bornholms Museum, Rønne, Denmark. R: Bead from Lille Karleby at the National Museum, Copenhagen, Denmark.)

What could the owners of the Lille Karleby hoard have been trading for these beads of rock crystal and over 200 beads of Near Eastern glass? Presumably not silver, since they were importing Arabic coins as well. But the coins in the hoard represent connections both east and west, suggesting that the people who buried this hoard had connections not just to the Near East and Central Asia but also out into the North Sea.

I’m still waiting to see the analysis of when these coins were minted, but from what I’ve seen so far, the hoard was probably buried sometime around the late 800s. This was a period when viking activity began to spike and Scandinavians began to set up permanent settlements across Western Europe. If this uptick in raiding and colonialism can be connected to the Lille Karleby hoard—and I think it should be—then we need to think carefully about what viking raiders might have been trafficking east so that their partners in the Baltic could acquire glass and semi-precious stones from Asia and the distant Abbasid caliphate.

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Two beads from the Lille Karleby hoard. The one on the left is common enough—a mosaic bead made from four tiles of glass (two with flowers, two with concentric circles) and capped with a red stripe on each end. The bead on the right is a bit of a mystery. The beadmaker started with a simple blue bead and then traced patterns all around it, mimicking the design of the bead on the left. Was this a rough draft, meant to advertise a beadmaker’s abilities without wasting precious mosaic glass? Or was it a commissioned fake, as the beadmaker tried to match a preexisting mosaic bead despite lacking the necessary raw materials? (National Museum, Copenhagen, Denmark.)

Central Places in the Viking Age

In the past two weeks, I’ve had the rare opportunity to look at necklace beads from both Uppåkra and Sorte Muld—two high-status sites from the Scandinavian Iron Age—back to back. Both sites drew great wealth from their positions at the crossroads of southern Baltic Sea routes, and both seem to have been flourishing centers for pagan cults throughout the early Middle Ages. Archaeologists call sites like these “central places” because they seem to have functioned as enduring focal points for the communities that lived around them. More recently, both sites have been the locations of major archaeological excavations (Sorte Muld 1985–87, 2001; Uppåkra: 1997–present). This work has dramatically increased what we know about Scandinavia between the Fall of Rome and the Rise of the Norse Sea Kings.

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One of my favorite beads from Sorte Muld. It’s similar to beads that have been found in southern Germany near Stuttgart and dated to the 500s—at a time when Sorte Muld was flourishing. I like it in part because the bead maker needed to twist the red-and-yellow glass in two different directions to make this design, just like a weaver might alternate S- and Z-wound threads. (Bornholms Museum, Rønne, Denmark.)

But with the advent of the Viking Age, our knowledge about both sites comes to an end. It’s not because these sites were abandoned. On the contrary, both have produced indicators that at least some measure of prosperity continued into the Viking period. The problem is that modern plowing has churned up the top 30 cm of soil, which corresponds roughly with the amount of soil accumulated in southern Scandinavia since the Viking Age. So although the topsoil at both sites contains numerous artifacts potentially dating to the Viking Age or later, archaeologists can’t connect these tossed and tumbled artifacts with a particular place from which they came.

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This spectacular bead from Uppåkra measures only 12.0×16.5 mm, and yet it contains over 1300 pieces of glass! This mosaic technique was used for many hundreds of years with many of the same basic designs. I’ve seen similar elements in Viking Age beads, but the very small scale of this glasswork seems more Roman to me. Since this bead was found in the plowed-up surface dirt, we don’t have many clues for a precise date unless we can find other, better-dated beads to compare with it. (Lund University Historical Museum, Lund, Sweden.)

The loose nature of these finds, however, is an advantage of another kind. Artifacts found in graves or buildings can tell us a lot about the lives of individuals and families. But the scattered finds from a settlement force us to think more about the community as a whole. And although my own interests lie in the Viking Age, these beads are mixed in with beads that must have come from earlier periods. I had the great opportunity to fill in some gaps of my own knowledge about these earlier beads, first by examining some of the Uppåkra beads together with Karin Lundqvist, a Swedish archaeologist who works on the earlier Iron Age, and later by looking at some of the unique finds from Sorte Muld with Torben Sode, a Danish authority on glass. This has allowed me to think more clearly about how the Viking Age fits into the longer histories of Scandinavian societies.

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A blue segmented bead from Uppåkra. Scandinavians imported these Middle Eastern beads in large numbers during the early Viking Age (750-850), although they were much more common at the crafts and trading town of Åhus than at the nearby central places of Uppåkra and Sorte Muld. (Lund University Historical Museum, Lund, Sweden.)

So what has my study shown us about these places? Well, first and foremost, it’s confirmed that their use and probably occupation continued into the Viking Age. And by comparing these collections to other collections of Viking Age beads, we can get a sense of what kind of communities Uppåkra and Sorte Muld became. For example, I recently studied a large number of blue segmented beads that came from the craftworking town of Åhus, and we know that these came from an area that was inhabited around 790–850. Both Uppåkra and Sorte Muld had similar beads, indicating that they were similarly occupied during these first generations of the Viking Age.

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This dark brown bead from Sorte Muld turns a pretty purple-pink when held up to the light. I saw several similar beads from Åhus but none from Uppåkra. This suggests that in the early 800s it was much easier for a merchant traveling from Åhus to sail 100 km (64 mi) by sea to Sorte Muld than to cross 75 km (47 mi) overland to Uppåkra. (Bornholms Museum, Rønne, Denmark.)

But they had these beads in much smaller numbers, suggesting that their connections to these new trading towns were in fact very limited. Instead, they had a large number of wound beads, which show up in all sorts and sizes. This variety is much more comparable to the beads I recently examined from Lousgård, a wealthy cemetery on Bornholm. So while the people living at Uppåkra and Sorte Muld may have had few direct interactions with the town sites of the new Viking Age economy, they nevertheless seem to have maintained their wealth and prestige.


A final note of thanks is due to the museum staff, researchers, and scholars who shared their time and resources with me in both Lund and Rønne. Their generous support has helped turn the objects of the past into valuable treasures for me, and I hope for others as well. Mange tak! Tack så mycket!

The Craftsman’s Purse

It was in the early 800s, and vikings raiders were sweeping across Northern Europe as western kingdoms collapsed into civil war. But by the shores of southern Sweden near the mouth of the Helge Å, one family prospered. Their home was simple—a shallow pit measuring 3×3 meters (10×10 feet) with a house pitched over it like a tent. A loom stood in one corner and a hearth in another. They feasted on fish, made pots for their leftovers, spun wool, wove cloth, carved amber, casted bronze, and traded for beads of glass.

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This small house in early Åhus measured 3.4 m (11 ft) by 2.8 m (9 ft). The two circles along the bottom left corner represent postholes from an earlier structure demolished before construction. The darker circles stand where the posts went to support the roof. The two dashed circles on the inside of the bottom right likely supported a standing loom. And the cluster of smaller circles at the top right stands for the jumble of rocks and pottery that remained from the family hearth. With an entire family confined to such a tiny space, it’s amazing that anything could fall to the ground unnoticed. (Tyra Ericson-Borggren, Report on Archaeological Excavations at Åhus, 1989-91.)

Admittedly, their lives haven’t attracted much attention. They left more trash than some of their neighbors, but less than others—if that’s any measure of wealth or importance. But when I saw the beads they let fall to their floor, I was stunned. For here amid the humble dwellings of Åhus, a handful of drawn and segmented glass beads had been abandoned among a family’s fishbones and broken pots.

These beads are admittedly small, but they could be precious. No one in Northern Europe could make such things, although some were beginning to try. A few families of glassworkers, it seems, shuttled back and forth between this small community of Åhus and a similar settlement on Denmark’s North Sea coast. They had little to work with, perhaps just a handful of glass pieces pilfered from old Roman mosaics, but they were learning to melt these bits of glass, wrap them around iron mandrils, and work them into beads both simple and advanced.

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This bead was likely made by one of the glassworkers who trafficked between Ribe and Åhus in the early 700s. Before making the bead, the glassworker prepared one twisted rod of red, white, and blue, and one rod of white and red. He or she then wound a plain blue glass bead around a metal mandril, wrapping the twisted cane of red-white-blue around its center and then tracing wave patterns with the red and white rod on either end. Altogether, this is an impressive work of craftsmanship, and it ended up being buried with an elite woman on Bornholm, where it was found earlier this year. (Bornholms Museum, Rønne, Denmark.)

The beads from this house at Åhus were made differently. If glass can be wound at a temperature of about 700° C (1300° F), the glass for these beads must have been heated to somewhere around 1000° C (1800° F). A small air bubble was blown into this liquified glass, which was then stretched into a long hollow tube. For the green bead in the back (now turned white from reactions with the soil), this was the final step. Once it had cooled, the tube was cut into small cylinders like the one we see here. The blue beads went one step further. They were rolled on a surface with regular ridges, giving the beads the appearance that they were made in several segments, as if they were several small beads stuck together. The narrow waists were convenient breaking points, and similar beads typically show up with anywhere between one and five segments. Sometimes these fractures got messy, like the blue double bead on the back left.

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Beads abandoned in the dirt by a family living in Åhus, Sweden, ca. 800. (Lund University Historical Museum, Lund, Sweden.)

The other beads, though much deteriorated, show evidence of yet another step. At some point in the production process, a fine metallic dust was added to make them shine like silver or gold. Over the long term, this has caused weaknesses in the glass, and many of these silver- or gold-foiled beads have started to peel like onions. The gold bead on the bottom left has lost some of its surface glass, and just above it is a piece of surface glass that came from a silver-foil bead, although the core of the bead itself is missing.

But here’s a close up of two beads that staggered me. The two-segment bead in the middle is what right looks like. The beads on either side, however, are missing their holes. There’s no way to string these beads into a necklace, or even to use them as beads. The closest furnaces capable of making these these beads were in the glass workshops of Syria and Iran. These beads then went through Constantinople and up the Danube to get to the Baltic. Or they went the longer way round via Marseilles, up the Rhône, and down the Rhine, before hitting the North Sea and rounding the tip of Jutland. Either journey is impressive, but I’m more impressed that nowhere along the way did anyone stop to check their cargo and discard these beads as worthless.

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Three segmented beads found in a house at Åhus, Sweden. They were all made in one of the major glass centers of the Near East sometime around the year 800. The beads on the right and left are missing their perforations, meaning that they had no functional use as beads. (Lund University Historical Museum, Lund, Sweden.)

There’s many possible explanations for this. For now I’ll withhold my conjectures. But whether early medieval merchants never paused to take stock of their wares, or whether they didn’t see these hole-less beads as worthless, either case provides much food for thought about how medieval people moved and valued their goods. And this simple family from Åhus, whose stories have been compressed into a mere 9.5 m2 (100 ft2), somehow had not only the economic reach to participate in exchange networks stretching all the way to the Mediterranean and the Middle East. They also shared in an interregional set of economic values that made beads like these worth collecting—in such great numbers that some even fell unheeded to the floor and were ground underfoot.

Colors of the Viking Age

We have little evidence for the colors of the Viking Age. Most people would have lived in a world of colors that drew on and deviated from the natural world—split wood, smelted metal, smoked meat, dyed wool. Few of these things preserve their colors through long years in the archaeological record. Wood decays to dirt, metal corrodes to rust, meats reduce to bone, and what wool survives has often changed into the reddish hues of the earth where it was buried. Only glass beads retain their colors and are in fact protected by the dirt which shelters them from the sun.

But bead researchers have often neglected to appreciate just how precious the colors of their artifacts truly are. Most researchers seem to have been daunted by the beads’ varieties as well as by the difficulties of describing colors which are, after all, a very subjective thing. Each person understands and describes colors differently, filtered through eyeballs that are as unique as an individual’s DNA, and conceived of in a language unique to each person’s experience of the world.

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Viking Age Scandinavians had more colors than your average crayon box. But while glass preserves these colors remarkably well, the ways in which we perceive and understand color have changed. How would a viking sort these beads? Which beads belong together? (Bornholms Museum, Rønne, Denmark.)

Nevertheless, I’ve been using the Munsell Color System to help me describe the colors that I see. Basically, this means referencing a book full of color chips representing the array of colors that most people can see and differentiate. Munsell in collaboration with the Society of Bead Researchers has helpfully published a slim volume of the 176 colors most commonly found in premodern glass. It’s kind of like selecting a paint chip at the hardware store. And although a color chip might not exactly match the object I’m looking at, and although it might be affected by the light of the sun or the warmth of a light bulb, these chips can still serve as a useful reference point that most people will recognize and agree upon.

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The Munsell Color System, with hues wrapped around the equator, black on the bottom, white on the top, and moving from gray at the center toward purer colors on the surface. (Image courtesy of Munsell Color. Used with permission.)

Perhaps most importantly, by using the Munsell system to describe colors rather than resorting to vague and overlapping terms like blue, teal, and turquoise, I can quantify what I see. Munsell colors indicate not only hue (think: red, green, blue) but also value (light or dark) and chroma (pure and bright versus dun and gray). These three values can be plotted onto a 3D map, which lets me look at how the colors of the Viking Age cluster into groups. Right now, I’m using a model which places gray at the center and radiates into purer colors at the surface, with richer colors fading to black in the south and brighter colors shading to white in the north. This is the basic Munsell model that’s been used and tested by thousands of researchers for well over a hundred years.

So while observers today might be tempted to describe the colors of the Viking Age in terms of red-green-blue (a color model meant to stimulate the yellow-green-violet receptors in the human eye) or cyan-magenta-yellow (absorbent colors that can mask unwanted wavelengths from background whites in our computer screens and on printer paper), people in the Viking Age seem to have sorted their colors differently. Here’s a quick map of all the colors that commonly appear in premodern glass. If a dot appears darker, it’s because it actually represents a range of values (shades of light and dark) which are nevertheless the same hue and intensity. For example, tomato red and brick red lie on top of each other, because both can be made from the same base color with the addition of either white or black. The dark dot at the center actually represents both white and black, but without any additional color shading added.

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The chart on the right shows how the Munsell system organizes all the hues of the rainbow. The dots on the left indicate all the hues likely to appear in premodern glass. Darker dots mean that these hues occur in varying brightnesses. (Munsell Hues image courtesy of Munsell Color. Used with permission.)

And here’s the colors of 1,429 beads that I’ve looked at. This represents only a subset of my data, selected from beads that were most likely made locally in Scandinavia. The glass itself would have been made and mixed in the Middle East—Egypt, Syria, and Iran were the early medieval centers for glass production—but the colors here represent the bits of glass selected by traders who traveled routes north between about 700 and 900 AD. The beads plotted here thus represent color choices made by several generations of people living between the Near East and Northern Europe.

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The chart on the left shows the colors observed for 1,429 Viking Age glass beads. Note how this represents only a small selection of the possibilities for premodern glass shown in the chart above. There are very few reds or yellows, few pure greens, and almost no purples or oranges. But dark dots show the popularity of colors near the center spanning from yellow to blue, with an especially wide variety of blue colors.

I think this chart is interesting in itself, since it shows some of the selections being made by glass makers, traders, and consumers during the Viking Age. This is important because pretty much anyone who could get glass did, and they showed it off to those who couldn’t both in their daily dress and in their public ceremonies. Glass was among the most modest and most valued of goods, and in many of the graves for individuals who merited few gifts, a glass bead or two is all that survives. But where this data gets really exciting is when we start grouping the colors. This is a pretty straightforward statistical analysis that looks for concentrations of data points and then tries to draw lines around the looser sets of data that surround them. Here’s what the color chart looks like when I broke it into five clusters.

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This is one of several cluster analyses I ran on my dataset of ancient glass beads. Although the results varied and my methods need to be refined, this particular clustering shows just how different Viking Age perceptions of color might have been from our own.

I must preface my comments by saying that I’m still learning how to choose and run statistical analyses, so my conclusions are by no means final. But what we can see here is really exciting. The blue dots represent the smallest variety of colors but the largest group of beads. These are dark blues that range from a purplish navy blue to a deep aqua green. But the red dots represent a broader range of colors that are blues pure and bright. The green dots represent lighter blues, overlapping with greenish colors like teal and turquoise and shading into even more yellowish colors like mustard and olive.

At the other end of the spectrum, the black dots represent a range of deep reds, browns, and oranges. I’m personally impressed by how closely these colors cluster around the colors of natural amber—there were lots of amber beads in my study but I excluded them from this analysis of purely glass beads. The light blue dots, however, represent a really loose cluster of bright reds and yellows. These were rarer colors during the Viking Age, so neither of them showed up in enough of a concentration to be modeled as a group of its own.

All this suggests that the Norse traders who plied Russian rivers might have perceived both dandelion yellow and fire engine red similarly as bright variants of a more fundamental amber hue. The vikings raiders who traversed the North Sea might meanwhile have seen more difference in light and dark shades of blue than in diverging hues of yellow, green, and purple. The Scandinavians who made, traded, or wore these beads all seem to have been people preoccupied with the intensity and depth of colors, rather than on our more recent interests of shade and hue.

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This necklace has fewer beads of dark blue than I’ve found in most necklaces I’ve looked at, but it captures better than most the rainbow of colors evident in the larger data set, with few reds and yellows but a greater sensitivity towards blues and blue-greens. From a burial on Bornholm ca. 775. (National Museum of Denmark, Copenhagen, Denmark.)

To offer credit where credit is due, Munsell Color has taken an interest in my research and even helped me access some of the materials that make it possible. They’ve recently published a brief article I wrote about classifying ancient colored glass. Plotting Munsell Colors is, however, a remarkably new method of analysis. I’m especially indebted to foregoing research by Roy G. D’Andrade and A. Kimball Romney on the relationship between Munsell Colors and human color perception, and by Lana Ruck and Clifford T. Brown on the application of Munsell Color mapping to archaeological contexts.

 

Counting Beads from Viking Age Bornholm

It can be bewilderingly difficult to describe a simple thing. At least, that’s my experience now that I’m back in Copenhagen examining Viking Age beads. At present, I’m studying beads from an important cemetery at Bækkegård on the Danish island of Bornholm. A government administrator by the name of Emil Vedel excavated most of the cemetery in 1876, blitzing through 156 graves in a mere 13 days. This means that records are minimal and the handling of some artifacts was haphazard.

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Beads attributed to Burial 66 at the Bækkegård cemetery on Bornholm. Other items in the grave allow us to date the burial to 750-775, or right at the cusp of the Viking Age. But to the original excavators, all the beads looked much the same and got mixed together by color. So although we know that Burial 66 received 20 blue beads in her grave, we can’t be sure that these are the same ones. (National Museum of Denmark, Copenhagen, Denmark.)

Beads in particular suffered from Vedel’s treatment. He recorded colors and numbers for each grave but then threw all the beads that he thought were worth keeping into containers for shipment to the National Museum of Denmark. The curators in Copenhagen resorted the monochrome beads into strings for each grave—although it’s unlikely that many of these beads actually came from the graves that they’re now associated with—and then they strung all the mixed polychrome and mosaic beads onto strings of their own.

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Vedel’s catalog of beads at Bækkegård from his invaluable Nyere undersøgelser angaaende Jernalderen paa Bornholm (1878). His categories of beads include mosaic, painted, varied, blue glass, green glass, other glass, yellow clay, and red clay. It’s not certain what Vedel thought the difference was between “painted” and “varied” glass, nor what exactly belonged to his “other” category. His “clay” beads are now known to be opacified glass. (Emil Vedel, Nyere undersøgelser angaaende Jernalderen paa Bornholm, 1878.)

Nevertheless, Vedel’s initial 156 graves plus an additional 12 that were found and excavated thereafter make Bækkegård the site of nearly half of all Iron and Viking Age graves found on Bornholm. And although other large cemeteries have been found in southern Scandinavia, including the massive grave field at Lindholm Høje on the Danish mainland, Bækkegård remains a site of great interest. The people who buried there preferred inhumation to cremation burial, which means that the artifacts these people were buried with remained largely intact, whereas those in a cremation cemetery like Lindholm Høje have mostly been burnt or broken beyond recognition. So while Bækkegård’s beads might not be attributable to any particular graves, they remain valuable as the one of the largest groups of necklace beads that can be attributed to a single site in Viking Age Scandinavia.

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Beads attributed to Burial 103 at the Bækkegård cemetery on Bornholm. Vedel recorded that yellow “clay” (actually glass) was the predominant material used for this burial’s necklace beads. Although these might not be the exact same beads that Vedel actually excavated, we know from the larger picture of cemeteries on Bornholm that yellow beads went out of style around 600, so I can safely exclude this necklace from my study while minimizing the number of Viking Age beads that I potentially miss. (National Museum of Denmark, Copenhagen, Denmark.)

And so, whereas earlier studies of Bækkegård and Bornholm have relied on Vedel’s simple listing of colors to deduce how necklace styles changed over time, I am one of the first researchers to examine the individual beads. They seem to be strung still on the original threads used back in the 1870s, and each bears a tiny tag with the catalog number written in a black ink that faded long ago.

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Beads attributed to Burial 109 at the Bækkegård cemetery on Bornholm. This mix of colors is appropriate for the period around 630-650, but some of the beads mixed into this reconstruction almost certainly date to the Viking Age. Although the blue beads from Bækkegård appear in many diverse styles, the light that shines through them usually appears in one of only three shades. With further research, I may be able to associate these colors with particular glass production centers in the Eastern Mediterranean, whereas the diverse styles might be attributed to more local bead makers working within Scandinavia itself. The red bead at the right doesn’t have bubbles like the blue beads next to it, revealing that this is a bead was made of amber rather than glass. (National Museum of Denmark, Copenhagen, Denmark.)

At this point, I don’t know what’s important, so I’m trying to take as many discrete measurements as possible for future analysis. I’ve got a data set of 261 monochrome beads thus far, representing styles that were used between 600 and 900 AD. For each bead, I currently have 44 columns of data. Most of this is as simple as I can make it, including date and time of analysis, museum and catalog number, provenance location, material, method of production, notes on condition or damage, shape (profile and cross-section), basic dimensions of the bead and its perforation, and the colors reflected and transmitted by the glass (i.e. sitting on a white surface versus having light shine through it). I also have a few columns where I can write notes about observations that my current data scheme doesn’t quite capture, such as irregularities in condition, shape, or color. All told, it takes me about 2-3 minutes to catalog each bead, plus time for photos.

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Mosaic and polychrome beads from the Iron Age and Viking Age cemetery at Bækkegård on Bornholm. The beads from Bækkegård comprise a beautiful but dizzying array of styles and techniques—the hard part for a researcher is figuring out how to record all these details. What details are important? And how do I record them discretely so that they can be correlated across a large data set taken from beads across Scandinavia? (National Museum of Denmark, Copenhagen, Denmark.)

Next week, I start tackling the polychrome and mosaic beads. To be honest, I’m daunted by the prospect. There’s so much variety and innovation during the Viking Age that I’m not quite sure how to capture it all in a meaningful way. I’ve consulted as many catalogues for other bead classification systems as I can find, and they’re all broadly divergent. This has been inspirational, since it allows me to pick the best pieces from each one. But it’s also discouraging, since it’s a clear reminder that even basic data collection is never unbiased, and the choices that I make about data collection now will determine the quality of my dataset for future analysis and interpretation.

 

Using X-rays to Study Early American Glass

It’s been a busy week since my last post about Queen Fredegund. I’ve had an opportunity to shift gears and start studying the nitty-gritty of glass composition. With the permission of the Boston City Archaeologist, I borrowed 60 beads from the City Archaeology Lab. Thirty of these were discovered in the 1980s during excavations for a water line near the Charlestown Navy Yard. These beads were tossed into an abandoned cellar around 1650, as Boston’s earliest buildings were being replaced during period of rapid development. They were some of the first glass beads to arrive in North America outside of the Spanish colonies. The other thirty beads came from the Industrial School for Girls in Dorchester on Boston’s south side. They were dropped into an outhouse sometime between 1860 to 1875, and they were excavated just last year as the site was being prepared for renovations.

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Beads selected from the Industrial School for Girls in Dorchester, MA, for this study. These thirty-three beads represent a small fraction of the beads dropped into an outhouse at a girls’ school between 1860 and 1875. Perhaps they they were the prized possessions of one of the girls being rehabilitated at this occupational school, or perhaps they are the survivals of one of the girl’s work projects. (City Archaeology Laboratory, Boston, MA.)

Although both sites fall well outside my main focus of study, this was an excellent opportunity to develop analytic techniques close to home. I took the beads to the Massachusetts Institute of Technology (MIT) Center for Materials Science and Engineering, which houses a state-of-the-art X-ray Diffraction Shared Experimental Facility. This facility is supported by the MRSEC Program of the National Science Foundation under award number DMR – 1419807, and my time there was generously supported by a grant for the public humanities being executed by Robin Fleming of Boston College. Over the course of a few days at the MIT CMSE, I used a Bruker Tracer-III with a rhodium X- ray source and a silicon-based detector to detect which elements were in the glass of each bead.

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My workstation at the Massachusetts Institute of Technology. The Bruker-III XRF Tracer is on the right, and the red light at its base shows that it’s on. A bead is under the black cap, which protects me from radiation when the device is running. The ziplock bag at the bottom center tells me I took this photo while scanning bead M.0199—a turquoise bead from the mid-1600s. The graph on the screen is a live reading of the results, and the high peak on the left means that Silicon atoms are sending X-rays back. This confirms that the bead is in fact made of glass, which has a Silicon base (SiO2). The other elements represent the particular recipe used to make this bead’s batch of glass, which has the potential to reveal when and where it was made. (Massachusetts Institute of Technology, Cambridge, MA.)

Despite the fancy engineering behind these elemental tracers, the basic science is quite simple. The Bruker tracer sends an electrical current through a Rhodium filament, just like a standard light bulb sends an electrical current through a Tungsten filament. In a regular lightbulb, the current causes electrons to get excited and jump around—a current is, after all, an imbalanced concentration of electrons that causes other electrons to jump from one atom to the next in the hopes of balancing things out. Each jump results in a release of energy that we see appear as tiny photons of light. But when an electrical current causes Rhodium electrons to jump, they produce photons at a different energy level which is invisible to the naked eye, or X-rays.

The tracer directs these photons into a stream at the given object, which in my case consisted of historic beads. The photons share their excitement with the atoms in these beads, causing the electrons to jump. When the electrons in a bead settle back down, they release energy photons of their own. The energy released by each photon depends upon how far the electron needs to jump, or just how big its atom is. Bigger atoms are heavier elements, and smaller atoms are lighter ones. The Bruker tracer measures the energy levels of the photons that come back, and so by registering just how much energy each photon has, we can tell which elements produced them. This method of analysis is known as X-ray Florescence (XRF).

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A sample reading from the Industrial School black beads. Most scans resulted in a peak of readings at the left at Silicon (Si), an indicator of glass, as well as on the right at Manganese (Mn) and Iron (Fe), two elements used to create black glass. The green line is strangely flat at these energy levels but instead peaks at Sulfur (S) and Titanium (Ti). What is this black bead, if it’s not made of glass or colored like glass? (Artax Screen Shot, Bruker Elemental Analysis.)

For now, I’ve been looking at qualitative data. For example, the chart above shows the readings from seven black beads excavated at the Industrial School for Girls. Six of them have the same peaks and valleys, but the green line has a different quality. It’s surprising that the green line is flat at the energy levels characteristic for Silicon (Si), a base element for glass, and Manganese (Mn), an element often used to blacken glass. The green line, however, shows unexpected peaks at Sulfur (S) and Titanium (Ti). So even without knowing the exact proportions of the elements that may have produced these peaks and valleys, we can tell that the green line represents a bead that isn’t glass.

In fact, the green line belongs to a bead probably made of vulcanized rubber, which was still a relatively recent invention when this bead fell into a privy in the 1860s. In 1844, Charles Goodyear had secured the patent, claiming: “My principal improvement consists in the combining of sulphur and white lead with the india-rubber.” India rubber referred to tree rubbers that were then being cultivated in both Asia and South America, and factories were soon using Sulfur to vulcanize this rubber in both Europe and North America. The Sulfur peak indicates that the key hardening agent is present in this sample, although a conspicuous lack of lead shows that recipes had already changed.

A bead like this one adapted the hard and dark qualities of this new rubber recipe to imitate the more costly jet, which was a mineral popularly used for jewelry in the 1800s. We know that Whitby in England was then the major center for Victorian jet production, whereas glass came predominantly from Bohemia (in the modern Czech Republic) or Venice, Italy. With all these places in mind, this graph helps us see how during the 1800s even the poorest Americans—girls who had been sent away to a school for wayward youth during those inward-looking decades of the Civil War and Reconstruction—had material contacts with a very international consumer culture. Is globalization that new after all?

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The bead in question. During the 1800s, glass beads were being made in Bohemia and Venice, but chemical analysis reveals that this bead spacer is actually a type of rubber hardened by adding Sulfur. The natural rubbers were likely a distant import, although the bead may have been made more locally to imitate expensive jewelry imported from England, and it was ultimately deposited with glass beads that likely came from Bohemia or Venice. Together, these artifacts help us understand how even the poorest Americans were being integrated into an international consumer culture even though our history books more often focus on the political events of the Civil War and Reconstruction. (Ebonite Bead from the Industrial School for Girls, Dorchester, MA.)

My next step is quantification, that is, taking these energy readings and deducing the likely glass recipes that would have produced them. I’m much indebted to Lee Drake for introducing me to this possibility. This type of analysis has the potential to be especially important for the early beads from Charlestown. All my Charlestown beads are turquoise, but the recipes for turquoise beads changed during the colonial period. These changes are already an active area of study for scholars like Ron Hancock and Elliot Blair. Quantifying my data will help me compare it to their earlier studies. These comparisons might help us more precisely date exactly when these beads were buried.

Remarkably, although the original excavators thought this filled-in cellar was “one of the earliest and best preserved colonial domestic artifact assemblages discovered archaeologically in New England,” we don’t actually know when these artifacts were buried. Our best guess is 1640–1660, based on the styles of a handful of smoking pipes found in the mixed assemblages. The ceramics (pottery) found in the cellar artifacts could date from this period, but ceramics had long lifespans and don’t actually help us narrow down a precise date. Beads, in contrast, had very short shelf-lives, so they might very well be our best opportunity for better understanding when exactly this assemblage of the neighbors’ trash was thrown together into an empty Charlestown cellar. This, in fact, is not so different from the short life-spans of popularity enjoyed by early medieval beads. Perhaps these sites aren’t so different from my own after all.

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A bead from early America, buried in a Boston cellar sometime around 1650. This cellar was close to the docks and therefore near the waterline. Although this helped preserve some artifacts (such as animal bones from dinner leftovers), it’s left the glass much corroded. This corrosion prevents basic observations, such as accurate recordings of color, size, shape, and weight. Fortunately, X-rays can let us see things naked to the human eye, helping us understand how this corroded bead fits in with other turquoise trade beads of the colonial period. (Turquoise Bead from the 17th-century Garrett Site, Charlestown, MA.)