TECHNICAL STUDY OF A CEREMONIAL SICAN TUMI FIGURINE

Examination of a Sican ceremonial tumi, dated to the Middle Sican, c. AD 850–1050, showed that it was made in a silver-copper alloy of approximate composition 93% silver, 6% copper. Many separate pieces are used in the construction, joined together by both mechanical methods and by solder. The principal figure has been made from 18 separate silver sheets, with 169 separate parts identified in the head-dress, totalling 187 design elements. Metallographic examination of a fragment of repoussé decorated sheet from the figure surmounting the tumi surprisingly showed that the silver-copper alloy has a cast morphology; this demonstrates that Sican metalsmiths were pre-casting silver-copper sheet into the dimensions required for making the tumi, rather than carrying out the expected process of making the idol from hammered silver-copper sheet, shaped by extensive cycles of working and annealing, thus contradicting the usual assumptions about the manufacture of sheet-metalwork made in such cases.     

The Material Characterization of a Santamarian Ceremonial Axe

The characterization of a ceremonial bronze axe is described. The axe is assigned to the Santamarian culture of north‐west Argentina, c. 1000–1470 ad, and was selected to increase presently limited knowledge of prehistoric metallurgy in the Andean region of Argentina. The characterization methods used were electron probe microanalysis, gamma radiography, X‐ray diffraction, optical metallography and microhardness testing. The axe was well cast in a bivalve mould, with the only defects in the area of an ancient fracture. The analysis showed that it is made from a tin bronze with a, probably, accidental addition of lead. Arsenic was found as a surface contamination, probably deriving from arsenic in the water of the stream in which the axe was found. The axe shows that Santamarian craftsmen had the skill to decorate the axe in an artistic style with a strong local accent while providing a functional, annealed and cold‐worked cutting edge.     

COPPER AND BRONZE DURING THE ENEOLITHIC AND EARLY BRONZE AGE: A METALLOGRAPHIC EXAMINATION OF AXES FROM THE NORTHALPINE REGION*

This paper presents the results of a metallographic examination of Eneolithic and Early Bronze Age axes from the Northalpine region of central Europe. During this period, different types of copper were in use: arsenical copper, Fahlerz copper and tin bronze. We examine if and to what extent the different properties of the metals used were known to prehistoric metalworkers and actively manipulated in the production of the axes. The development of methods of casting and smithing is discussed. Both aspects contribute to our understanding of the nature of prehistoric technological change. During the Early Bronze Age of the Northalpine region, different traditions of early metallurgy can be identified, which differ in their use of Fahlerz copper, their attitude towards tin alloying and the use made of tin bronze in the production of the axes. These traditions can only be adequately described by reference to both composition—that is, access to different types of copper as well as tin—and knowledge of the production techniques provided by metallographic data.     

ARCHAEOMETALLURGICAL CHARACTERIZATION OF HELLENISTIC METAL OBJECTS: THE CONTRIBUTION OF THE BRONZE OBJECTS FROM RISHON LE‐ZION (ISRAEL)*

An archaeometallurgical analysis is presented of 14 bronze artefacts retrieved from an Early Hellenistic–period farmstead in controlled archaeological excavations at Rishon Le‐Zion, Israel, and dated to the first quarter of the third century bce according to coins and pottery vessels. The bronze assemblage includes a needle, pins, spatulas and fibulas. The aims of the research are to determine the composition, microstructure and manufacturing process of these artefacts, and to discover their place of production. This will provide a better understanding of Hellenistic technological abilities and material culture. The examination included optical microscopy, microhardness, SEM including EDS, and XRD. The results show that the collection consists of Cu–Sn binary alloys, with evidence for a controlled alloying process and the absence of recycling. Furthermore, the microstructure of the objects indicates that all artefacts were produced by a cold‐working process. Moreover, the manufacturing process of the rectangular cross‐section fibulas included sophisticated joining techniques of copper and iron.     

MICROANALYTICAL METAL TECHNOLOGY STUDY OF ANCIENT NEAR EASTERN BRONZES FROM TELL BEYDAR*

Forty‐six bronze objects have been investigated to assess their composition and microstructure, using SEM–EDX and optical microscopy. The bronzes originate from Tell Beydar, a site in the northeastern part of Syria that was mainly occupied during the third millennium bc . The compositional results of the metals show a clear chronological sequence in the use of the alloying elements arsenic and tin. In addition, the microstructure indicates advancement in the metalworking techniques that were used.     

THE METALLURGY OF THE NAHAL MISHMAR HOARD RECONSIDERED

The Nahal Mishmar hoard, found in a cave in the Judean Desert in 1961, is a key find for the study of Chalcolithic metallurgy in Israel and the Levant. Recent analyses of Chalcolithic metalwork from sites such as Shiqmim in Israel raised doubts about the validity of published analyses from the hoard. Accordingly a programme of re-analysis was established using atomic absorption spectrometry and electron probe microanalysis. The new analyses confirmed the doubts and showed that the metallurgy of Nahal Mishmar was the same as that at the other sites. The alloys used for the cast products in the hoard were generally ternary arsenic-antimony copper alloys with up to 20% alloy content; less common were compositions with arsenic and nickel. The unusual metallography of these alloys is described. Some suggestions are offered as to the mode of manufacture of the alloys.