Due to the increasing number of locations and methods of analyses, due to the lack of Reference Materials specially concerning the elemental composition of archaeological copper alloys, due to the non-traceability and non-comparability of the published results, any reliable historical reconstruction on statistical ground is hopeless.
The aim of this project is to make available reliable tools for achaeometers and for researchers in the field of conservation. These tools are:
- Certified Reference Materials for calibration of bulk elemental analysis of ternary and quaternary copper alloys.
- A good analytical-practice guide for the use of EDXRF for the study of the bulk elemental composition of archaeological metallic artefacts.
- A good analytical-practice guide for the study of the surface of artefacts in cases where the investigation should be non-destructive.
- Assessment of the limits of the correlation between outer (corroded layers) and inner (uncorroded layers) composition
- Improvement and optimization of the electrolytical methods available to monitor corrosion behaviour.
Five Certified Reference Materials representing the main families of metals found in Antiquity from the very beginning of metallurgy until the Roman Period, will be fabricated: copper being the base metal: impure copper, arsenical copper, tin-bronze, leaded bronze, and tin. The impurities contained in the ancient metals will be reproduced taking into consideration the problem of homogeneity.
At this stage the IFAO, EDF and SEK have been working on the determination of the first two compositions. IFAO prepared a bibliography including 203 objects and analyzed 200 other objects from Egypt and the Eastern Mediterranean which gave a suggestion for the first composition for a Reference Material: this composition is that of the arsenical copper. EDF and SEK have performed a similar work on objects from Western Europe. This study lead to the choice for the composition of the second Reference Material: this composition is that of leaded bronze. The three other compositions are to be determined soon.
The next stage is the fabrication of these Reference Materials according to the given percentages respecting their homogeneity. This has been the object of some speculations because of the volatility of certain elements and the insolubility of lead in copper.
Funding SchemeCSC - Cost-sharing contracts