Silver and the Silver Economy y b e at Hedeby d e H t a y m o n o c E r e Stephen William Merkel v l i S e h t d n a r e v l i S BEIHEFT 33 BEIHEFT 33 9 783867 570176 1. Chapter about the origin and use of silver from the archaeometry Viking Age. In order to investigate these themes, inter- of silver artifacts, crucibles, and production debris? What disciplinary methods are needed that integrate the fields Raw Materials, Innovation, Technology of Ancient Cultures can elemental compositions and lead isotope ratios re- of archaeology, history, numismatics, and the natural RITaK 2 veal about the state of silver mining, commerce, and sciences through archaeometry. The five themes are as technological development in the early medieval period? follows: This thesis is an attempt to apply modern analytical tech- niques to explore these basic questions. 1. Silver Recycling in the Viking Age The use of archaeometry to better understand the The Vikings obtained foreign silver to be recycled trade and production of silver in the early medieval pe- and refashioned into new objects such as the Hedeby riod greatly expanded in the 1960s and the present study coins, ingots, and jewelry. Silver was certainly recycled is a continuation upon this tradition; however, the current at Hedeby and elsewhere in the Viking world, but the study departs from this tradition by the state-of-the-art question is how this was carried out. Was it refined and methods of analysis. Through a combination of tech- cleansed of its impurities? This theme is meant to explore niques, and chiefly through laser ablation mass spec- the recycling, refining, and testing / assaying technolo- trometry, new information is made available that has gies used by the Vikings to develop an understanding never before been obtained from Viking silver. Recent of metallurgical knowledge and the economic role and developments in laser ablation techniques and mass consciousness of silver purity. spectrometry allowing for the precise and accurate de- termination of elemental and lead isotope compositions 2. Silver of the Islamic World show great promise for the study of archaeological silver The Vikings had access to the silver of the Islamic and have the potential to answer questions concerning world; however, there is little clarity concerning the state the provenance and technological aspects of metal pro- of mining in the Islamic world during the Viking Age. The duction and use. goal of this theme is to explore the historical, archaeo- In spite of these ground-breaking improvements, logical, and archaeometric evidence and chronological the interpretation of elemental and lead isotope compo- development of silver mining in regions under control of sitions of the silver of this period is no simple task. There the Islamic dynasties and to characterize the composi- are precedents for the methods and interpretation of the tion of silver used with the analysis of dirhams and pro- archaeometric analysis of silver; however, the present duction debris from production sites in the Arabian Pen- study requires an approach specifically adapted to the insula and Central Asia. material and cultural context. Any interpretation must be grounded in a fundamental knowledge of metallurgical 3. Early Medieval Silver Mining and Silver Coin Com- and geochemical processes and must take into consid- position eration the body of archaeological, historical, and nu- The aim of this theme is to contrast evidence for mismatic research about trade and metal production in mining obtained through historical and archaeological the early medieval period. Only within this context can records with the evidence obtained by elemental and the archaeometric analysis of Viking silver be applied lead isotope analysis of silver coins. This comparison with any hope of success in providing information about can help to support arguments for or against mining in the past. various regions in the early medieval world. The ele- The coin finds and silver objects from Hedeby form mental and lead isotope analysis of silver can provide the core material for this study, and the primary research indirect evidence for the existence of mines that are goals are to characterize and interpret the changes to presently unknown. Due to compositional dissimilarities, the silver stock in southern Scandinavia during the 10th silver can be divided into types that, in all probability, and 11th centuries. Coins are arguably the most infor- do not stem from the same origin, and vice versa. The mative inorganic object type found in the Viking period. archaeology and historical accounts of mining regions Their inscriptions and stylistic details make it possible from the early medieval period can not be deemed as to determine their origin to an extraordinary degree and sufficient in representing the actual state of mining to date their production in some cases to the year. For during this period because neither record is complete. these reasons coins form a central focus. Although the Although all traces of mining may now be destroyed, primary goal of this study is to understand the compo- arguments of early medieval silver production can be sition of the silver stock used for the Hedeby / Danish built using a combination of factors such as silver com- coins, this cannot be understood without understanding position, existence of suitable ore deposits, evidence the metallurgical processes used during the early medi- for earlier or later mining, prolific minting near a depos- eval period nor the potential origins of the silver. There- it, etc. Though firm evidence is rare in such cases, the fore, several themes must be explored simultaneously evidence should be considered because it may be the to build an interpretational framework for the understand- only still existent. Long standing issues like the begin- ing of silver compositions. The research questions have ning of large-scale silver mining in the Harz Mountains been divided into five themes, each exploring diverse and the possible production of silver in Anglo-Saxon but interrelated aspects of the study of silver during the England will be explored. 16 1. Chapter Introduction to Silver and the Silver Economy of Hedeby Silver and the Vikings contention and discrepancy. Following lieber (1981, 12), the looting and pillaging of monasteries and towns is The silver hoards of the Viking Age attest to the well-known through the annals of history and the sagas, importance of silver in the society of early medieval and to this day the Viking Age is cognitively associated Scandinavia. The theme of silver in the Viking Age is with violence, brutality, and tumult; the economic matters the focus of numerous scholarly books and articles, and of the time such as peaceful trade, acquisition of re- yet it has never lost an air of mystery nor the ability to sources, and production are rarely mentioned in the texts captivate. This is because the silver of the Vikings pro- of the period. The role of commerce and production in vides a seemingly boundless source of information about the Viking Age is an area where the archaeological re- the economic and cultural development of Viking Scan- cord provides the greatest evidence (see saWyer 1990). dinavia, which was inseparably connected to the devel- The methods of archaeology form a basis for the explo- opments of a large expanse of the world (see ration of such mundane ‘everyday’ matters through the Graham-Campbell/Williams 2007; Graham-Campbell et physical remains of material culture left behind. Just as al. 2011; skre 2008). Silver acquired a special signifi- archaeology offers alternative frames of reference from cance in Scandinavia over the course of the Viking Age the historical and literary sources in understanding the not only as a material of prestige but as a medium of past, the field of archaeometry, which is the interdisci- exchange. It is relatively scarce in the 9th century in plinary study of archaeological remains with methods Scandinavia, but evidence for its use grows exponen- borrowed from chemistry, material science, and geology, tially in the 10th century (saWyer 1990, 285-286). It is provides further perspectives and can be used to dis- commonly accepted that the majority of this silver was cover aspects of the past that cannot be found in any brought to Scandinavia by long-distance trade (lieber other way. 1981); why so much silver ended up in Scandinavia and where it came from are not new questions, but are still current topics actively discussed in academic circles. Archaeological Questions and The exchange network that connected Scandinavia Approach to lands both near and far was complex and dynamic. The finding of Islamic silver dirhams in Scandinavia clear- A number of silver objects have been discovered ly demonstrates this point. From these dirhams scholars at Hedeby, a trading center of extraordinary importance of Viking history have known for over 150 years that for the Danes and the Viking world at large. Remains of during the Viking Age trade routes crossed the Caucasus the recycling of precious metals have been found in and the steppes of Central Asia linking Russia and the addition to numerous silver coins and fragments. There Baltic to the Islamic world (loWiCk 1976, 24). The trans- is an academic consensus that a mint was located at portation of silver over such expanses in the Viking Age Hedeby and that it operated intermittently from the 9th seems to be counterintuitive; epitomized by spufford to the 11th century (malmer 2002; WieChmann 2007). As (1988, 68), where he states, “... the dirhams survive as there are no silver mines in the area of Hedeby, the a witness to this strange long-distance trade.” For those coins produced at Hedeby must have been made of familiar with the historical accounts of Viking raids on recycled silver imported via the long-distance trade western Europe it seems more sensible to assume that routes, trade routes that stretched from Samarqand in the silver used and hoarded by the Vikings was stolen, the east to the North Atlantic in the west. The relative extorted, or plundered from the Christian West. chronology of the Hedeby / Danish coinage of the 9th to Ideas of the role of the Vikings in the growth of 11th centuries has been established, and this chronolo- maritime commerce are in continual movement and are gy spans a period where the archaeological and numis- constantly being reinterpreted as new evidence comes matic evidence indicate several shifts in the trade routes to light. Gradually our understanding of the Viking peri- of silver. Several tantalizing questions can be asked: is od from the written sources is becoming merged with it possible to determine where the silver used to make the archaeological record, a merger that is not without these Danish coins came from? What can be learned 15 Silver and the Silver Economy at Hedeby Stephen William Merkel Raw Materials, Innovation, Technology of Ancient Cultures RITaK 2 VML Verlag Marie Leidorf Bochum 2016 Acknowledgements Montanhistorische Zeitschrift Der ANSCHNITT. Beiheft 33 = Veröffentlichungen aus dem Deutschen Bergbau-MuseumBochum, Nr. 216 There are many individuals to thank who contribut- isotope analysis and her effort is recognized. The staff Cover image ed to the development of this thesis. Firstly, I would like at the material science laboratory of the Deutsches Berg- Reconstruction of a dock into the Hedeby harbor. The wooden to thank Andreas Hauptmann. As my primary supervisor, bau-Museum must also be recognized for their work. platforms were not only used to dock boats, but probably the he provided me with ample opportunities to learn and Michael Bode has helped greatly in many ways, and I area functioned as the market place. (Photo S. Merkel). always encouraged me to broaden my perspective in would like to thank him for his hard work. I would also the fields of archaeometallurgy and archaeometry. I am like to thank Andreas Ludwig, Sandra Morszeck, Regina Frontispiece greatly in his debt for the countless lessons that have Samme, Dirk Kirchner, Marion Jung, and Michael Prange This is a photo of the Steinfeld hoard consisting of coins helped me to grow as a researcher. Secondly, I would for help and advice. probably minted at Hedeby (10th century AD). Image courtesy of Archäologisches Landesmuseum in der Stiftung Schleswig- like to recognize the diligent support of Volker Hilberg. As a member of the graduate school ‘Raw Materi- Holsteinische Landesmuseen Schloss Gottorf. As an advisor he has provided me with much insight als, Innovation and Technology of Ancient Cultures’ I into the workings of the early medieval world and has gratefully acknowledge the Leibniz-Gemeinschaft for Dissertation of the Fakultät für Geschichtswissenschaft at the helped to guide me through a number of mazes: medi- providing the financial support, Thomas Stöllner as Ruhr-University Bochum in 2015. This work represents the state of research in 2014 at the time of submission. eval numismatics, the research history of Hedeby, the speaker of the graduate school, and Petra Eisenach as magazines of Schloss Gottorf, just to name a few. Third- coordinator. My fellow PhD students are a source of ly, I would like to thank Christoph Bartels. Through our comradery and inspiration, and I would like to specifi- numerous conversations he has challenged me to think cally name Patrick Könemann, Arne Windler, Hande outside the box and has increased my understanding of Özyarkent, Michael Klaunzer, Lena Asrih, and Moritz medieval mining and metal production exponentially. Jansen. Externally, I would like to recognize Claus von The analytical data produced in this study could not Carnap-Bornheim and Ralf Bleile from Schloss Gottorf Funded by have been obtained without the help of several individ- for their support. Additionally, I would like give thanks to uals. I would like to acknowledge the work of Robert Leonid Sverchkov and Nick Boroffka for their help in Lehmann and Daniel Fellenger from the Leibniz Univer- acquiring samples of ore and slag from Uzbekistan. I sität Hannover. The expertise of Robert in the use of gladly thank Jenny Garner and Anton Gontscharov for laser ablation was invaluable and the data produced help with understanding Russian texts. forms the foundation of the present thesis. From the Last, and most of all, I would like to thank my wife, Goethe-Universität Frankfurt-am-Main, Sabine Klein has Ellen. My wife and my new family in Germany have been In Kommission bei also made a valuable contribution by performing lead exceptional and have provided me with constant support. VML Verlag Marie Leidorf GmbH, Rahden/Westf. Geschäftsführer: Dr. Bert Wiegel Stellerloh 65 · D-32369 Rahden/Westf. Tel: +49/(0)5771/ 9510-74 Fax: +49/(0)5771/ 9510-75 eMail: [email protected] Homepage: www.vml.de Abstract Bibliografische Informationen der Deutschen Bibliothek Die Deutsche Bibliothek verzeichnet diese Publikation in der Deutschen Nationalbibliografie; detaillierte bibliografische Daten sind im Internet über http/dnd.ddb.de abrufbar. In the 10th century there is an archaeologically de- evidence for the processing and purification of silver tectable transition in the origins of silver in the Baltic uncovered at Hedeby will be investigated to possibly Begutachtet durch region from an eastward focus on Russia and Central gain information on the value of silver and the importance Prof. Dr. Andreas Hauptmann, Dr. Volker Hilberg, Prof. Dr. Claus Asia to a westward focus on Anglo-Saxon England and of silver purity in the early medieval economy. The use v. Carnap-Bornheim the Ottonian Empire. Since Hedeby was an important of multi-collector laser ablation inductively coupled plas- Redaktion gateway of the eastern trade and the western European ma mass spectrometry (MC-LA-ICP-MS) has not previ- Stephen William Merkel, Bochum trade at this time, it is an ideal place to study this tran- ously be utilized to characterize lead isotope signatures Satz sition. The aim of this project is to study silver, primari- of Viking-age silver objects from northern Europe and Petra Eisenach, Bochum ly in the form of coins from Central Asia and western/ Central Asia. It is a promising technology that allows for Central Europe to compare them to the locally minted the microscopic sampling of objects to obtain the isotope Titelgestaltung coins from Hedeby to learn more about the potential information needed to reliably source silver and lead. Hans-Jörg Lauffer, Bochum und Petra Eisenach, Bochum sources of silver and to better understand the movement This study will explore the application of this technique Druck of silver in the 10th-11th centuries. Lead isotope data and in the analysis of silver objects of the Viking Age, and druckhaus köthen GmbH & Co. KG, Köthen elemental compositions will be used to look closely at its usefulness in the study of the medieval trade of silver ISBN 978-3-86757-017-6 the transfer of metals during this time period. In addition, will be critically evaluated. 13 Preface In 2011 the Senate of the Leibniz Association grant- sued their goals with passion and energy. The success ed funding for a three and a half year Graduate School of the Graduate School was also a result of the friendly with the title “Raw Materials, Innovation and Technology and supportive atmosphere that the DBM and RUB re- of Ancient Cultures” (RITaK). The RITaK School was and search teams could provide for “our” PhD students. I is organized in collaboration between the Deutsches gratefully acknowledge our Advisory Board, particularly Bergbau-Museum Bochum (DBM) and the Ruhr-Univer- Professor Dr Barbara Ottaway (Exeter) and Dr Beatrice sity Bochum (RUB). It provided a number of doctorate Cauuet (Toulouse), who always encouraged our stu- students an ideal research environment but also stimu- dents to persevere in following their pathways. As coor- lated and strengthened the institutional collaboration dinator, Dr Petra Eisenach was vital to the School and between the DBM and RUB. helped us to avoid the many pitfalls and to overcome all Through this initiative, it became possible to explore sorts of difficulties. She also undertook the layout of this archaeological questions within a broader multidisci- second volume of the RITaK publication series. plinary approach: Eleven doctorate candidates worked One of the first to conclude his studies was Stephen side by side with their supervisors and other associated William Merkel. Stephen attended the program from the researchers to study the access to, use and significance beginning. He arrived a few weeks late and was really of raw materials for early societies in all their complex- exhausted by traveling from the USA, but he managed ity. Empirical research and theory were used to search to be the first to lay his excellent thesis on our table. for the role of technical knowledge and the meaning of Stephen worked constantly and with passion on the sil- innovation in early societies. Going beyond the econom- ver from Hedeby, always supported by our DBM labo- ic worth of things, material and objects became trans- ratory team, but also by the Hedeby research team in mitters of ideas as they became “charged” with cultural Schleswig where he profited much from close collabo- meaning and importance. The social side of material ration with Dr Volker Hilberg. His interests quickly ex- culture helped raw materials and technologies to be ac- panded far beyond Central and North Europe to the cepted and incorporated into the social practices of com- Islamic East in Central Asia and the Middle East. The munities, thus stimulating the transformation of culture fruits of his work are now in front of our eyes. I am sure and the economy. that the study will become a seminal work for under- The Graduate School lasted officially until the end standing Viking silver and the far-reaching exchange of 2014 with the conclusion of nearly all of the PhD networks that were connected with it. research projects that started at the beginning. It is a fantastic achievement for the doctoral students who pur- Thomas Stöllner vi Contents Preface                                                       vi Acknowledgements                                               13 Abstract                                                      13 1 Chapter Introduction to Silver and the Silver Economy of Hedeby                          15 Silver and the Vikings                                            15 Archaeological Questions and Approach                                   15 Structure of the Thesis                                            17 2 Chapter Archaeometallurgy of Silver An Overview of the Early Medieval Period                  19 21 Introduction                                                19 22 Silver Ore                                                 19 221 Silver and Lead-Based Ore: Cerussite and Galena                      20 222 Fahlore as Silver Ore                                      20 223 Jarosite as Silver Ore                                      21 224 Sphalerite as Silver Ore                                     21 225 Comparison of Ore Quality: Texts versus Archaeology                     21 23 Principles of Smelting Lead and Silver                                  22 231 Lead and Lead-Silver Production                                22 232 Complex Smelting: Jarosites and Polymetallic Ore                       23 24 Cupellation                                                24 241 Cupellation and the Refining of Impure Silver                         24 242 Cupellation of High Grade Ore and Mercury Amalgamation                  25 243 Cupellation: Trace Element Fractionation                            25 Lead                                                    25 Bismuth                                                  25 Copper                                                   25 Gold and other Noble Metals                                       25 Antimony and Tin                                             26 Zinc                                                    26 Mercury                                                  26 244 Cupellation Summary                                      26 25 Alloying, Recycling, and Metalworking                                  26 251 Alloys, Impurities, and Working Properties                           26 252 Testing of Purity                                         28 Pecking, Bending, and Nicking                                      28 Touchstones                                                28 Specific Gravity                                              29 Fire Testing and Assaying                                         29 Summary and Conclusion                                         30 253 Adjusting Silver Purity and Recycling Practices                        31 Minting and Cupellation                                          31 Minting Recycled Silver without Refining                                  32 Implications of Recycling Technology in Archaeometallurgy                        33 254 Surface Treatments – Intentional and Unintentional Implications               33 26 Closing                                                  34 3 Chapter Hedeby and the Silver Economy of the Viking Age                               35 31 Introduction                                                35 32 Hedeby                                                  35 33 Money, Exchange, and the Role of Silver in the Viking Age                       37 331 Why Silver?                                           38 332 The Development of an Exchange Medium                          38 34 Coins, Rings, Ingots, and Hack silver                                  39 341 The Development of Coinage in Southern Scandinavia                    39 3411 Frisians and Sceattes                                       42 3412 The Beginning of Scandinavian Minting                              42 3413 The 10th Century: Carolus / Dorestad and Cross Coinage                    42 3414 Hedeby and Danish Minting in the 11th Century                         43 3415 Conclusion                                             43 342 The Aurar System, Hacksilver, and the Bullion Economy                   43 3421 Ring Money and Ingots                                      43 3422 Hacksilver                                             45 3423 The Relationship of the Methods of Payment                           46 35 Closing                                                  47 4 Chapter Silver Mining and the Trade of Silver in the Early Medieval Period                     49 41 Introduction                                                49 42 Survey of Mining Regions                                        49 421 Mining in the Islamic West, in Eastern Europe and in Western Asia              50 4211 Lead and Silver Mining in Morocco and Spain                          50 4212 Silver Mining in the Balkans                                    51 4213 Lead and Silver Mining in Anatolia and Greece                          51 4214 Lead, Silver, and Gold Mining in the Arabian Peninsula                     52 422 Silver Mines of Iran, Afghanistan, and Central Asia                      52 4221 Lead and Silver Mining in Iran                                  52 4222 Mining in Afghanistan: Panjhīr and Farinjal.                            53 4223 Silver Mines of Transoxania                                    53 4224 The Pamir and Talas Regions                                   54 423 Silver and Lead Mining in Christian Western Europe                      54 4231 Melle and the Cevennes                                     54 4232 Silver Mining in England and Ireland                               55 424 Silver and Lead Mining in Central Europe                           56 4241 Silver Mining in the Rhenish Massif                                56 4242 Silver Mining in the Harz                                     58 4243 The Upper Rhine Valley and Neighboring Regions                        58 4244 Eastern Central Europe                                      59 425 Closing                                             59 43 Coins, Trade Routes, and Chronology                                  60 431 Medieval Silver Circulation prior to the 10th Century                      61 4311 Circulation of Silver in the 9th Century: The Carolingians                     61 4312 Circulation of Silver in the 9th Century: The Eastern Route                    62 432 Circulation of Silver Coinage in the 10th and 11th Centuries                  63 4321 Changes to the Eastern Trade Route                               64 4322 Silver of the West: The Harz and Beyond                            64 44 Closing                                                  66