Previous studies on Roman folles have evidenced strong variations in Ag content in coins of different period of coinage. Also, evidence of a thin silver enriched patina has been found. However no systematic investigation has been carried out on the patina characterisation. In the present work we propose a method based on the use of a PIXE portable system in order to evaluate the patina composition and, in combination with a portable XRF technique, to estimate its thickness. Both portable systems were realised at the INFN/LNS Catania laboratory. The method was tested by using "dummy" samples consisting of a silver enriched thin-surface layer of different thickness deposited on an Ag-Cu substratum. The method has been applied to two Roman folles. In the near future it will be used in a systematic study of the known "Misurata Treasure" (Libya).
Non destructive investigation of the Ag distribution in the late roman folles from about 300 to 333 AD
S Garraffo;A Nicolosi;L Pappalardo;FP Romano
2008
Abstract
Previous studies on Roman folles have evidenced strong variations in Ag content in coins of different period of coinage. Also, evidence of a thin silver enriched patina has been found. However no systematic investigation has been carried out on the patina characterisation. In the present work we propose a method based on the use of a PIXE portable system in order to evaluate the patina composition and, in combination with a portable XRF technique, to estimate its thickness. Both portable systems were realised at the INFN/LNS Catania laboratory. The method was tested by using "dummy" samples consisting of a silver enriched thin-surface layer of different thickness deposited on an Ag-Cu substratum. The method has been applied to two Roman folles. In the near future it will be used in a systematic study of the known "Misurata Treasure" (Libya).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
