Provenance, authentication and residue analysis of some Māori taonga using portable X-ray fluorescence

Tuhinga 30: 256-268

ABSTRACT: A box of unaccessioned New Zealand Māori bone and pounamu (greenstone) taonga (treasures) from the Museum of New Zealand Te Papa Tongarewa was investigated using portable X-ray fluorescence (pXRF) to establish the environmental origins (provenance) of its contents in a non-destructive way through trace element analysis. Eighteen unidentified bone taonga underwent pXRF analysis using 37 trace elements, and were classified into marine and terrestrial origins based on strontium concentration. Three taonga that appeared to be pounamu were also compared elementally with genuine pounamu taonga held in the museum to establish their authenticity. Heavy metal residue treatments were found on the surface of all the bone objects analysed, with one item registering levels of arsenic up to 326 ppm and of lead up to 2054 ppm. This highlights the need for routine surface analysis of museum heritage objects and careful handling protocols, not only for object care but also for curatorial health and safety.

KEYWORDS: trace elements, taonga, portable X-ray fluorescence, heavy metal, bone, New Zealand, strontium, marine, terrestrial, pounamu, heritage, indigenous, authenticity, provenance, Museum of New Zealand Te Papa Tongarewa.