GeoArch offers a service in the analysis and interpretation of archaeometallurgical residues. The materials investigated are wide ranging, but the core expertise is in metallurgical slags, with an emphasis on those from iron-making and -working. Recent commercial projects have included iron-making slags of the earliest pre-Roman Iron Age or latest Bronze Age from the Thames Valley, iron-making slags from the Iron Age of Ireland, Roman and Saxon smithing slags from the Cotswolds, Iron Age and Norse slags from the Hebrides, Medieval iron-making slags from South Wales and Iron Age and Early Medieval slags from Ireland.

Assemblages are normally investigated in two stages:

• An evaluation involves examination of the materials visually and under a low-powered stereo microscope. Normally the evaluation includes production of a brief catalogue of the material, an overview of the identification and interpretation of the material and an evaluation of its potential, with a recommendation for any further second-stage investigations.
• The second-stage investigation may involve, for instance, application of optical- or electron-microscopy, chemical analysis (analysis by X-ray fluorescence, XRF, or induction coupled plasma optical emission spectrometry, ICP-OES, for whole sample major elements; induction coupled plasma mass spectometry, ICP-MS, for trace elements) or crystallographic analysis (by X-ray diffraction, XRD).

Locations of archaeometallurgical residues and iron ores studied in recent projects

The analytical service makes use of the excellent analytical and imaging facilities of Cardiff University's Schools of History and Archaeology and Earth Ocean and Planetary Science.

A method statement for customers for clients in Ireland requesting licences to export and to alter is available here here.