Handheld methods in archaeological research on large copper alloy assemblages: HH‐XRF against HH‐LIBS

Abstract

When alloy composition information is sought across a single large artefact assemblage, how well do handheld methods solve the problem of museum environments which restrict the movement of artefacts and destructive sampling, and which have limited in‐house technical resources? The usefulness of relatively low‐cost handheld analytical instruments still needs evaluating in such arenas. The potential advantages which handheld laser‐induced breakdown spectrometry (HH‐LIBS), with its affordability, speed and micro‐destructive corrosion‐penetrating ability, might offer over handheld X‐ray fluorescence (HH‐XRF)/portable X‐ray fluorescence (pXRF) in large intra‐assemblage comparisons of broad copper alloy composition were examined and reported on by the present study (tin and lead being the elements of interest). The context was an archaeological study in a major Greek museum, aimed at exploring the social and economic significance of alloying choice at a single large representative site of the Bronze–Iron transition, c.1200 bc. Archaeological interpretations are presented in another paper, with the alloying patterns/choices identified only being outlined in the present paper. The results of the methods comparison described suggest that HH‐LIBS has potential, but that HH‐XRF, despite its variable limitations in relation to penetrating corrosion (discussed here), is still the most reliable method for work in such circumstances.

Robotic arm material characterisation using LIBS and Raman in a nuclear hot cell decommissioning environment

“…The robotic mounts developed can be adapted for other techniques and probes of similar formats. The mount for HH-LIBS can be adapted to other hand held instruments available that operate in a similar manner, such as, X-ray fluorescence (XRF) [74], hyperspectral imaging (HSI) and Fouriertransform infrared spectroscopy (FTIR).…”

Socioeconomic Crisis and Cultural Innovation: The Lba‐eia East Mediterranean via a Case Study of Lasithi, Crete

“…1938; Wallace 2020d; Wallace 2020e, 83–101; Wallace et al . 2021; Wallace in review) with textile tools. While ‘traditional’ whorls parallel other ordinary/working types of artefact in their distribution, cylindrical whorls and loomweights do not.…”

“…At Karphi, recent analyses on 155 excavated objects show modest targeted use of over‐optimum alloying with tin or tin‐rich bronze metal, also focused on decorative and personal items (Wallace et al . 2021; Wallace in review; Figs. 8–9).…”

Mobility and Metals: Insights on Manufacturing, Consumption, Knowledge and Procurement Networks at the Bronze–iron Transition From the Karphi Assemblage

“…Few other contemporary Aegean settlements sharing these characteristics of size, complexity and single-period occupation have been excavated, producing a lack of comparably informative metals assemblages. This contextual interpretative study considers in-depth knowledge of the archaeology of the site and its landscape alongside the results (published and discussed in Archaeometry in 2021) of surface HH-XRF testing on the whole assemblage. The latter is preserved in similar condition throughout, offering opportunities for broad internal alloy composition profiling by the latter method, as well as limited general compositional comparison with other assemblages from the contemporary Mediterranean.…”

“…Καθώς λίγοι μόνο οικισμοί αυτής της περιόδου με παρόμοια χαρακτηριστικά (μέγεθος, πολυπλοκότητα και κατοίκηση μίας φάσης) έχουν ανασκαφθεί στο Αιγαίο, δεν έχουμε στην διάθεσή μας άλλα τόσο πλήρη συγκρίσιμα σύνολα μετάλλινων αντικειμένων. Η παρούσα ερμηνευτική και συνκειμενική μελέτη των μετάλλινων ευρημάτων τα προσεγγίζει με δύο τρόπους: μέσα από την σε βάθος γνώση της αρχαιολογίας του χώρου και του τοπίου γύρω απ’ αυτόν και αξιοποιώντας τα αποτελέσματα της ανάλυσης επιφανείας HH-XRF όλων των μετάλλινων αντικειμένων (ήδη δημοσιευμένα στο Archaeometry 2021). Ο βαθμός διατήρησης είναι ομοιόμορφος σ’ ολόκληρη την επιφάνεια των αντικειμένων προσφέροντας τη δυνατότητα να επιτευχθεί ένας ευρύς χαρακτηρισμός της σύνθεσης του κράματος στο εσωτερικό τους χρησιμοποιώντας αυτή τη μέθοδο.…”