Archaeological Finds of Jet from Norway Signs of Continuous Contact Westwards in the Viking and Medieval Periods?
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Archaeological Finds of Jet from Norway Signs of continuous contact westwards in the Viking and Medieval Periods? lleid (;josteinltesi The point of departure for this article is the find of half of a fingerring of jet from the archaeological excavations at VesleHjerkinn, Dovre, Oppland. The site is inter preted as a mountain lodge at the main trail over the mountains between eastern Norway and Nidaros (Weber 1986, Weber forthcoming). The site contains several buildings dated to the period 1Oth to the 13th century. The jet ring was found in a waste mound close to one of the buildings. Its closest parallels are found among the jet jewellery of supposed British origin from Norwegian Viking Age finds (Shetelig 1946). Gaming pieces and beads of jet from excavations of medieval towns, and beads from stave church sites show that the use of jet extended well into the Middle Ages. It is not clear whether these later findsindicate continuous contact westwards with the same supposed origins of jet as in the Viking Age, or if they originate fromother areas. The jet ring fromVesle Hjerkinn is relatively narrow (ea 4 ), has a round-oval mm cross-section and an outer/inner diameter of 2.4 /1.6 cm (Fig. 1). Its slightly worn surface appears shiny under magnification, although it is far fromhighly polished. Fig. 1. Finger ring ofjet from Vesle Hjerkinn (C. 37230/98). Photo: Ellen Holte, Kulturhistorisk museum, Universityof Oslo. Collegium Medievale 2005 Archaeological Findsof jet from Norway 87 Jet and similar raw materials Much of the literature on jet has a starting point in Pliny the Elder's (23/24-79) account inNatura/is Historia, Book 36, where jet was named aftera river, a region or a city in Lycia (in present day Turkey) called Gagas. German Gagat, French jais and Englishjet have the same origin. It is doubtful whether it is really jet, and not asphalt Pliny described from Lycia. Both materials were known as gagates lapis in Latin, but asphalt, not jet is known today from these regions (Allason Jones 1996: 5). Jet is a type of brown coal formed from fossilised wood from a tree similar to the present-day Araucaria that grew during the Jurassic period approximately 180 million years ago. When the trees died, some fell into wetlands, or into rivers that eventually carriedthem to the sea. Plankton and other sediments impregnated the wood and contributed to the chemical change of wood to jet. Analyses of the oil content have shown that so-called hard jet was formed in salt water, while softjet originated in fresh water. Both have the same hardness (3-4 on the Mob's scale), but hard jet is more solid and resistant while soft jet is more brittle and cracks more easily when being worked upon or when exposed to heat. Jet, like amber, is lightweight and develops a static charge when rubbed. When it is broken, jet delaminates into shell- or snail-shaped flakes and the wood's fine annual rings can sometimes be seen with the naked eye. Jet has an intense, black colour, and worked surfaces can be polished to a mirror-like finish (Muller 1998, with further references). Other jet-like materials such as cannel coal and shale have oftenbeen regarded as equivalent to jet in the past. According to Dr. J. M. Jones of the Fossil Fuels Institute of the University of Newcastle who has analysed Roman jet objects in Britain, «Jet as a term means different things to different people, but to a geolo gist the term is applied only to a form of vitrinite generally derived from logs of wood washed into the sea, where the airless sediment of the sea floor was rich in the remains of planktonic material» which impregnated the wood (Jones 1996: 54). «Cannel coal is formed fromplant debris accumulating as a sediment on the a lake in the coal-forming swamp» while «Shale is a common sediment bottom of 1, which consists almost wholly of clay minerals» (Jones 1996: 54). According to J. M. Jones ( 1996: 54), one method of determining the quality of jet, which also may aid in determining its provenance, is to measure its reflectance. Jet may be James Graham-Campbell equates «lignite» with «cannel coal» (1980: 66). 1 Collegium Medievale 2005 88 Heid Gjostein Resi viewed as a material made up of two parts, a wood-like vitrinite and a pitch-like substance. One may assume that jet with a relatively high vitrinite content will not attain as high a polish as jet containing more pitch-like material. Jones' research shows that Yorkshire jet has lower reflectancethan jet fromSpanish sources. The Spanish province of Galicia and Yorkshire are the relevant sources of jet examined by Jones, and may also prove to be the most likely sources for the Nordic finds from the Viking and Medieval Periods. The German archaeological literature mentions lignite and sapropelite as similar materials used for jewellery, in addition to jet (Rochna 1961 : 333-335; 1963: 186-187). Cannel coal corresponds to the so-called truesapropelite (Rochna 1961 : 334). It is claimed that it is relatively easy to distinguish jet, lignite and sapropelite (Rochna 1963: 186-1 87). Early use of jet and similar materials Jet and similar lightweight, black-brown materials were used as raw material for jewellery and figurines in parts of Europe from the late Palaeolithic (Klug Treppe 1996: 31 3). In England the use of jet increased during the Bronze Age, exemplified in the form of beaded necklaces and V-perforated buttons. From the I st century BC, traces of turning are registered on jet arm rings from this area. However, the use of jet became especially popular in Roman England during the 3'd and 4th centuries, reflected in the beads, brooches, pendants, arm and finger rings that have been found. Production continued on a smaller scale during the Ang1o-Saxon and Viking Ages. In the Medieval Period jet was worked around Whitby, Yorkshire, and shale was worked on the Isle of Purbeck, Dorset. During this time, both in England and in the jet-rich regions of Galicia in Spain, produc tion focused mainly on crucifixes,rosary beads and figurines(A llason-Jones 1996, with furtherreferences). Sources of jet of varying quality are known throughout the world. In Europe, sources have been located in England, Germany, France, Spain, Portugal, Turkey and Russia. In Norway there are also unexploited sources of jet on And0ya and in Beitstadfjorden, Tr0ndelag2• British sources of jet are largely confined to the Yorkshire coast. Areas around Whitby in Yorkshire are thought to be important early sources of jet production, through its availability on the shore and perhaps Personal communication, Richard Binns, Trondheim. 2 Collegium Medievale 2005 ArchaeologicalFinds of jet from Norwa y 89 00� LONG� 2 A. M8UOGROWSDAl {B.M71c) �Ynt® �-\}@ 5 OUiSTAD.1I<l<lA1.A>«< (IU116� 9 •• 0-0 Fig. 2. Beads (1-11), rings (12-15) andfigurines (16-18) ofjetfromNorwegian VikingAge graves (Finds list 1). Collegium Medievale 2005 90 Heid Gjcstein Resi 1 S0NDRE FELT, OSLO (G 15734) EIDSKOG CHURCH, HEDMARK (C 31902 2 v ,w) Gl.JI ' 3 AI. STAVE CHURCH, BUSKERUD (C 30955 a-c) . G. - o· ·I • 4 - ;'{/( � 0 1 NORE STAVE CHURCH, BUSKERUD HOVED0YA MONASTERY, OSLO (C 32376 (C 15340 IV) b) q Ci-�' - 6 MO CHURCH RUIN, OPPLAND VIKE CHURCH, BUSKERUD Scm (C 36454/40) (C.33227 B) Fig. 3. Beads of jet from the Medieval Period. Cityfinds (1). church finds (2-7) (Finds list 2). Collegium Medievale 2005 ArchaeologicalFinds of jet from Norway 91 also by mining. The Kimmeridge Clay formation, extending fromDorset to Tees side, was an important source for shale (Jones 1996). Jet of exceptional quality from Galicia and other nearby areas in Northwest Spain was also used during the Medieval Period. German researchers look to SchwiibischAlb as the likely source for theHallstatt period's Central European jet products (Rochna 1962: 69-70, Ab b. 5). Jet was worked at in SchwiibischGmiind in the 15th century. In the same region large deposits of lignite are also found. On the other hand, sapropelite, represented in the large findfrom Manching, originates from Schlan and the Plzen basin in the North of the Bohemian region, Czech Republic (Rochna 1961), based on results from analytical investigations. Norwegian jet finds from the Viking and Medieval Periods A small but significant number of objects of jet or jet-like material are found in Norwegian Viking Age graves. Only a few grave finds have been made since H. Shetelig's important article (1946) (see Finds List 1). Most of the objects originate fromwomen's graves(9 women's graves, I man's grave) fromthe gm century (a total of 14 graves), more seldom from the tom century (4 graves). The finds are mostly relatively large beads (Fig. 2.1-12), a few rings of different sizes (Fig. 2.13-15) and animal figurines(Fig. 2.16-18). With two exceptions (B.9471 from Longva, an animal figure and one bead, and Ts.9669 from Sund, one bead and one ring) only one jet object was found in each grave. This may imply that jet objects were highly valuable but when it comes to the beads perhaps a fine selection of beads of different forms and materials was in tune with contemporary fashion. H. Shetelig stressed that the spread of Norwegian jet finds closely corresponds with the distribution of so-called Irish metalwork, centred in western Norway, especially Rogaland, but also further northalong the coast (Shetelig 1946, fig . 7). Shetelig suggested that this may be connected with the cultural impulses gained by Viking raids westwards.