[B._Beckhoff,_et_al.]_Handbook_of_Practical_X-Ray_(b-ok.org).pdf

Au ores can be identified by the fingerprint of the

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Au ores can be identified by the fingerprint of the platinum elements, which Constantinescu et al. [666] showed on the gold coins from the Dacian, using PIXE and EDXRF. For copper ores, Bowman et al. [667] could iden- tify different types with the assumption that the traces can be found in the artefacts too. Identification of Mints The identification of a new unknown type of coin and relating it to a mint is a task of the numismatists. In the ancient and Middle Ages often the coin had no inscription. Here, the determination of the production technique in combination with the composition of the coin is helpful in solving the problem. A total analysis is necessary including the bulk and surface investigations. Most ores had to be refined and alloyed before they could be used as coin blanks. Both are time consuming processes and need high technical standards. A sign of a bad mint master is the appearance of elements as the residues of ores in the coins. The determination of Br in silver tetradrachme is a typical example (using PIXE, EDXRF and PAA [666, 668]) and could be attributed to a Barbarian workshop. 7.8.8 Conclusion The investigation of coins are often performed using XRF methods due to the demand for a nondestructive method. But the information about the metal content is reduced to the near surface layers, which can differ from the bulk material. Here, the results of XRF investigation are critical with respect to determining the excavation history and production technique of the coins. It is helpful to evaluate the XRF results with other methods such as the NAA, PAA or WCA. The determination of the specific gravity is a frequently used method [669] for the main elements Au and Ag in gold coins, which can be easily added to the determination by XRF.
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712 J. Zi¸eba-Palus If precaution is taken during the preparation in consideration, the XRF is a favourable method to analyse coins. The near surface nature of EDXRF in- vestigations is excellent for the detection of blanching and plating techniques. 7.8.9 Recommended Reading Most literature deals with the numismatic interpretation of the analysis re- sults. Very helpful journals are “Archaeometry” and “The American Journal of Numismatics”. In addition, the publications of the Royal Numismatic So- ciety are of interest because four special publications have the titles: “Metal- lurgy in Numismatics”. A French series of monographs is the Cahiers Ernest- Babelon, which are sister-publications to Metallurgy in Numismatics. 7.9 Analysis for Forensic Investigations J. Zi¸ eba-Palus 7.9.1 The Specificity of Forensic Research One can mention a number of characteristic features of forensic chemical analysis – strictly related to its forensic aspect – which differentiate it from other kinds of analyses. The aim of forensic chemical investigations is, above all, the identification of various materials, constituting evidence in court cases.
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  • Spring '14
  • MichaelDudley

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