An Assessment of Osmium Isotope Ratios as a New Tool to Determine the Provenance of Gold with Platinum‐Group Metal Inclusions

Bibliographic Data

ID8352691
AuthorsS A Junk (Jungheinrich (Germany), corresponding author), Ernst Pernicka (0000-0003-4746-9239, TU Bergakademie Freiberg)
Year2003
Volume45
Issue2
Pages313-331
Publication date2003-05-01
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueArchaeometry (JOURNAL)
Journal identifiersISSN: 0003-813X • E-ISSN: 1475-4754
PublisherWiley (PUBLISHER • GB)
DOI10.1111/1475-4754.00110
OpenAlexW2105322238
LanguageEN
Citations received10
References cited21

The sudden increase in the amount of Celtic gold coins circulating in central Europe during the second century bc coincides with the appearance of platinum‐group mineral (PGM) inclusions in the Celtic gold. It has been proposed that large amounts of gold were introduced from the eastern Mediterranean by mercenaries following the conquest by Alexander the Great, but another hypothesis might be the discovery of entirely new gold sources in central Europe during this time. The presence of PGM inclusions in gold objects is usually taken as an indication for an origin from placer deposits ( Hartmann 1970 ; Park 1986 ). Initially, it was hoped that those inclusions could be characteristic for a certain deposit, but Meeks and Tite (1980 ) have shown that the compositional variation within a single gold object can be as large as the total variation observed in all investigated gold artefacts. Therefore, the elemental composition of the PGMs in gold artefacts does not provide any reliable information on the provenance of the gold. An alternative to chemical analysis of the inclusions is the determination of their osmium isotope ratios. Similarly to lead, osmium exhibits a variable isotopic composition due to the radioactive decay of 187 Re and 190 Pt. In order to investigate the potential of this new geochemical tool to determine the provenance of ancient gold, a quasi‐non‐destructive method for the determination of Os isotope ratios with LA–MC–ICP–MS has been developed. The results show that different types of deposits can be distinguished by Os isotope patterns and their distributions when applying a simple descriptive statistical method. In contrast to lead isotope ratios, the variations of Os isotope abundances are rather large in many ore deposits. But, also contrary to lead, the heterogeneity of the Os isotope ratios of the deposits is preserved in the artefacts, because the analysed PGMs are not dissolved during melting of the gold. Therefore, it is feasible to distinguish between different types of gold sources and to define specific deposits provided that the artefact contains several PGMs. The application of this new technique to Celtic gold coins from southern Germany and coins from western Anatolia has been demonstrated in this study

Geochemistry · Isotope · Mineral · Mineralogy · Osmium · Placer deposit · Placer mining · Platinum · Platinum group · Provenance · Ruthenium · Archaeology and ancient environmental studies · Chemistry · Cultural Heritage Materials Analysis · Geological and Geochemical Analysis · Geology

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