Tag Archives: Sweden

Conference Proceedings: Gemstones in the first Millennium

Researchers from different fields like archaeology, history, philology and natural sciences present their studies on ancient gemstones. Using precious minerals as an example, trade flows and craftsmanship, but also utilisation and perception are discussed in a cross-cultural and diachronic approach. The present volume aims at three main questions concerning gemstones in archaeological and historical contexts: »Mines and Trade«, »Gemstone Working« as well as »The Value and the Symbolic Meaning(s) of Gemstones«.

 

This volume contains the proceedings of the conference »Gemstones in the first Millennium AD« held in autumn 2015 in Mainz, Germany, within the scope of the BMBF-funded project »Weltweites Zellwerk – International Framework«.

You can preview the table of content and a preface here.

Manufacturing and uses of backing foils – some technical experiments

Hello, I am Christiane Stempel, goldsmith, conservator and responsible for the technological examination of Early Medieval garnet objects that have been brought to the Römisch-Germanisches Zentralmuseum in Mainz for scientific analyses within the project “Weltweites Zellwerk”.

During my work, I made some observations that raised questions regarding the manufacturing and the use of the patterned foils behind the garnets.

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Fig. 1: Schematic figure of an Early Medieval garnet cloisonné (photo: RGZM/Ober)

Transparent stones were often underlaid with gold foils to reflect the light through the stone. This is particularly important when the stone is backed up with cement. In the Early Medieval period textured backing foils were used on a large scale. The three-dimensional pattern increased the reflective effect. I examined a great number of objects from different find-spots in Sweden, Anglo-Saxon England and the Rhineland and I found all the varieties of pattern commonly known from the literature such as standard waffle, boxed waffle (Varying in the number of enclosed squares [9 to 25]), ring-and-dot, lozenge, boxed lozenge and rectangle (stack bond). They only differ in fineness (number of lines/mm), depth of texture and contour sharpness.

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Fig. 2 a-f: Foil pattern (RGZM/Stempel)

 

Unfortunately, the project nears its end and I would like to use the remaining time to carry out some technical experiments:

Producing the pattern

There are indications (see figures 3-7) that at least a number of foils weren’t manufactured with dies. It looks as if lines were traced immediately on to the foils to form the grid pattern.

Fig. 3: Buckle, Ailenberg, Württembergisches Landesmuseum Stuttgart A.V. III333 (photo: RGZM/Stempel)
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Fig. 4: Disc brooch, Junkersdorf, Römisch-Germanisches Museum Köln 51,539 (photo: RGZM/Stempel)
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Fig. 5: Disc brooch, Monsheim, Römisch-Germanisches Zentralmuseum Mainz O.15370 (photo: RGZM/Stempel)
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Fig. 6: Disc brooch, Iversheim, LVR Landesmuseum Bonn 1960.667 (photo: RGZM/Stempel)
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Fig. 7: Disc brooch, St.Severin, Römisch-Germanisches Museum Köln 50.286 (photo: RGZM/Stempel)

N. D. Meeks and R. Holmes described in their article “The Sutton Hoo Garnet Jewellery” an experiment with a scriber that they used to draw the lines directly onto the foils. But in their opinion, the result was not satisfying. (N. D. Meeks/R. Holmes, The Sutton Hoo garnet jewellery: an examination of some gold backing foils and a study of their possible manufacturing techniques. Anglo-Saxon Studies in Archaeology and History 4, 1985, 143-157.) I would like to pick up the idea again, but instead of a scriber I will do the work with a profiled hand-operated tool, comparable to a creaser. It is used until today in bookmaking and leather processing to imprint decorative lines onto a leather surface. In contrast to a pointed scriber the elongated working face of a creaser can be of any cross-section.

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Fig. 8: Creaser (photo: RGZM/Steidl)

 

The theory that has to be verified in practice is as follows:  The grid pattern can be formed with a sliding forward motion of the tool, running it along a ruler with moderate pressure to form parallel lines, then rotating the workpiece by 90 degrees and repeating the action. For my experiments, I will use a small creaser-like tool that I have made by removing the cut of a square rifle file. As foil materials, I will use tin foil (0.03 mm) as well as sterling silver foils of different thicknesses (0,025 mm to 0,04 mm).

Using foil for stone securing

Not a small number of foils seem to have a further purpose: In many cases, the foils are trapped between the stone edges and the surrounding metal of the setting. Is it possible to hold a stone in place with the foil?

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Fig. 9: Disc brooch, Hürth-Kalscheuren, LVR Landesmuseum Bonn XV (photo: RGZM/Stempel)

If times permits, I would like to produce a foil in the way outlined above using a fire-gilded silver foil. In the next few weeks, I will report about my experiments and I am curious about the results and your comments.

 

Featured image: Buckle, Endre socken, Statens Historiska Museet Stockholm 484:12, detail: garnet cloisonné with foils behind the garnets. (photo: RGZM/Stempel)

An early medieval garnet workshop in Gamla Uppsala, Sweden

Lecture held by John Ljungkvist, Uppsala

 

The project “Gamla Uppsala – the emergence of a mythical centre”, has since 2009 conducted systematic studies in Gamla Uppsala to increase the knowledge of the long term structural history of the site. In the period c. 550-700, the place is transforming remarkably into a monumental site. This transformation of an already densely settled site involves the famous mounds, houses on artificial plateaus and recently discovered post row monuments. Three areas were in 2011 investigated in the centre of the Early Medieval manor area. Beyond a major reinterpretations of the great 7th c. hall/-sal, the excavation also contributed in shedding new light on settlement continuity, crafts, large scale household economy and regulations of the site between c. 400-1600 AD. Of particular interest for this presentation is the Northern Plateau, placed in a 90 degree angle in relation the great hall. This partially artificial plateau, house, in between earlier and later phases, two 6th c., two large burnt down houses from the 7th to 8th c. The older building, of which only small remains have been examined, proved to be a multi-functional crafts building where the garnet production is the most prominent activity. The building most likely houses tens of thousands of garnet fragments from the jewellery production, which makes it the so far largest production site found so far in Scandinavia.

 

Lecture held during the conference “Gemstones in the first Millennium AD. Mines, Trade, Workshops and Symbolism.” October 21st, 2015 at the Roemisch-Germanisches Zentralmuseum, Mainz (Germany).

Further reading on the web:

Blog by John Ljungkvist

Garnet jewellery in early medieval sweden (presentation)

Resources according to the archaeological research at Gamla Uppsala in Swedish:

Homepage

Arkeologerna blog posts

Societas Archaeologica Upsaliensis

Upplandsmuseet Uppsala

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