Wooden artefacts from the Oseberg collection contain various metal compounds arising from factors such as alum-treatment, the use of metal joiners and storage in metal tanks. Such compounds can significantly influence the condition of the wood, and therefore inorganic characterisation is important to include in studies of the wood. Using XRD, FTIR spectroscopy and SEM-EDS, we have been able to characterise metal compounds in several alum-treated wood fragments, including alum decomposition products, iron and zinc corrosion products and combinations thereof.