Here is an interesting paper in the same field as that of Eeva Jonsson above: Merkel, S., Hauptmann, A., Hilberg, V. and Lehmann, R., 2015 Isotopic analysis of silver from Hedeby and some nearby hoards In Viking Worlds. Things, spaces and movement, edited by M.H. Eriksen, U. Pedersen, B. Rundberget, I. Axelsen and H. Berg, pp. 193-210. Oxbow, Oxford. While the Jonsson study concentrated on silver content standard, this one looks at the "elemental signature" of the metal used, finding a surprising absence of silver coming from the British isles in Viking coins. This would change the nature of Viking plundering, to put it crudely, from robbery to feed the folks back home to violent taxation.
Peter
Silver played an important role both as a material of status and as a medium for exchange in the Viking Age. Hedeby was at the frontier between the monetized kingdoms of the West and the hacksilver/bullion economy of Scandinavia and the Baltic. Fueled by the influx of newly mined and recycled silver from the Middle East, Central Asia, and Europe, mints were irregularly maintained at Hedeby and across Denmark in the 9th–11th centuries. A diachronic study was undertaken to examine the flow of silver as a raw material at Hedeby from the 10th–11th centuries with the use of elemental and lead isotope analysis. Sampling of coins was done by Laser Ablation Inductively Coupled Plasma Mass Spectrometry, allowing for precise and accurate analyses with limited damage to the objects. The minting campaigns at Hedeby provide an excellent chronologic mirror to the changing sources of silver.