Ilon Gábor szerk.: Pápai Múzeumi Értesítő 6. (Pápa, 1996)

Bronzkor a Nyugat-Dunántúlon - P. I. Maclaen - J. G. Mcdonell: New archaeo metrical investigations of the bronzes in the Carpathian Basin. Újabb természettudományos adatok a Kárpát-medencei bronzok összetételéről

The above represent some of the current views regarding antimony bronze alloys. The following deals with results from the most recent set of analyses conducted on the samples described previously. Results and Interpretation From the sixty samples taken from chemical and metallographic analysis, 25% (15) of these were found to contain high antimony contents (i.e. >1% Sb). Metallographic study of the high antimony artefacts revealed that they were all in the „as-cast" condition with no evidence of subsequent working. Typlogically, these artefacts were restricted to ingots and edged weapon groups (spearheads, swordblades, axes, arrowheads) in the latter group one may normally expect to see some degree of subsequent working on the edges. Of particular analytical interest, EDAX analyses of a sample taken from a large spearhead piece from Velem St. Vid (See Figure 1.) revealed a composition of 82.2% Cu, 5.7% Sb, 2.6% Sn 7.5% Pb, 1.4% Ni, 0.2% Fe - essentially a leaded antimony bronze; and from Romand a „black" ingot containing 69.3 Cu, 23% Sb, 5% As, 2% Pb, 0.6% Ag and traces of sulphur. The black/purple coloration may be from the presence of silver chlorides/sulphides at the surface. To our knowledge this is the first identified high Sb/As piece from this site. From other analyses conducted on antimony bronzes from the Carpathian Basin (Helm 1900, Dr. László Költő pers. comm. and forthcoming 1996) it is known that such alloys are not so typologically restricted as may seem from the above case. High antimony contents have also been found in decorative items such as pendants and fibulae. Our current results find that elevated levels of antimony are found in predominantly unfinished / broken objects. However the findings may be simply a function of sample size. The microstructurcs of these alloys can be complex due to their often polymetallic nature and even in regard to the ternary Cu-Sb-Sn system there has been little systematic investigation in the regions and under the conditions of concern (the high copper comer in an „as-cast" i.e. rapidly cooled state). No constitution diagram exists for As-Cu-Sb alloys. The intermctallic phases tend to be extremely brittle as one would expect and a better chat acteristaion of these structures is one of the aims of this study. In consideration of the previously proposed reasons for tiie presence of antimony bronze alloys: antimony would have a useful hardening effect for objects such as edged weaponry however all samples examined come from broken or seemingly unfinished objects (e.g. casting lines still present) so the success of such an approach has still to be determined. From the analyses it is clear that antimony is not substituting for tin as a result of the tatter's lack of availability. Seventy five percent (75%) of all samples analysed contained quantities of tin, 85% of the samples from Velem St. Vid contained tin as the primary alloying clement so this possibility may be discounted. In regard to the aspects of colour and ritual/status (not necessarily mutually exclusive), the results are not yet conclusive and arc still viable avenues of research for the bronzes of the Carpathian Basin. Further investigation into the typological / contextual occurrence of these alloys is needed. Conclusion Research continues in this important yet little studied area of archaeometallurgy. Future aims of this work include the further definition of the microstructural characteristics of antimony bronzes for reference purposes; an expansion in the sample population to better delineate the extent of the alloys in the Carpathian Basin and to further investigate and substantiate the possible functions of such material as already outlined. It is hoped that the ongoing study of this material will help raise awareness of the existence and importance of these alloys among the wider archaeological community. Acknowledgements Thanks are due to the many people and institutions whose help, advice and hospitality have made this research possible, including Dr. K. T. Biró, Dr. I. Gcdai, Dr. T. Kovács, Dr. T. Kemenczei, Dr.