DETECTION OF NEAR-SURFACE SILVER ENRICHMENT ON ROMAN IMPERIAL SILVER COINS BY X-RAY SPECTRAL ANALYSIS

Autor: H. Bubert, R. Klockenkämper, K. Hasler
Rok vydání: 1999
Předmět:
Zdroj: Archaeometry. 41:311-320
ISSN: 1475-4754
0003-813X
DOI: 10.1111/j.1475-4754.1999.tb00985.x
Popis: A collection of 218 Roman imperial silver coins, covering three centuries, was analysed non-destructively by two variants of X-ray spectral analysis. Electron beam excitation and energy-dispersive spectrometry was used for the analysis of the uppermost thin layer (3 μm) of each coin, while X-ray tube excitation and wavelength-dispersive spectrometry was applied for the analysis of thicker layers (30 μm), Ag and Cu as major constituents and 18 minor elements were determined quantitatively. Comparing the silver content of the obverse and the reverse of a coin, inhomogeneities could be identified. By comparison of the silver content of the upper thin and the thick surface layers, near-surface silver enrichment could be detected. Inhomogeneities and enrichments increase in the second and more so in the third century. A large scatter of the silver content and silver enrichment for coins of the same emperor was attributed to varying abrasion of Ag-enriched layers of the individual coins during decades of circulation.
Databáze: OpenAIRE
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