Forgotten Realms, Forgotten Alloys: Exotic Metallurgy in Bronze Age Europe
The study focuses on a previously little studied area of archaeometallurgy, that of antimony bronze: copper - antimony alloys usually containing between 2 - 12 wt.% Sb. These alloys were first discovered in the archaeological record during the mid 1890's, primarily from Late Bronze Age / Early Iron Age Hungarian contexts (Urnfield period). Initial identification by (wet) chemical analysis, identified the presence of high antimony, copper alloys, most notably at the site of Velem St. Vid in western Hungary. Prior to this, antimony had only been discovered in the archaeological record as an unalloyed element used for small decorative items such as buttons and beads mostly found during excavations conducted in the Caucasus (e.g. Koban).
One hundred years after its identification, the current work has endeavoured to provide a detailed re-examination on the question of antimony bronze. The project considers known manufacturing centres, distribution, physical metallurgy and postulated reasons for the existence of these now extant alloys.
Based on examination of artefacts from both 19th century and modern excavations, in conjunction with a series of laboratory produced alloys, a suite of techniques have been used to illicit information on this select group; these include optical metallography, Scanning Electron Microscopy, X-Ray Diffraction, X-Ray Fluorescence, Neutron Activation Analysis and mechanical testing.
For the first time in a century, modern chemical analysis confirms the existence of antimony bronze in the European archaeological record. Results show that antimony is often not the only element present, the alloys can also include tin, lead and arsenic in appreciable quantities (percentage levels). Lower levels of silver, nickel and iron may also occur. The complex elemental nature of these alloys may reflect the originating copper source which is often alluded to as the `Fahl' (pale) ores i.e. tennantite - tetrahedrite mineral series (ideal formulae: (Cu,Fe)12As4S13 - Cu12Sb4S13). Tin would have been added separately or been included through recycling of non Sb-bronze.
Typologically this material shows a select distribution, appearing in ingots and decorative items (e.g. pins, buttons) but not in tools (chisels, sickles, knives) where the latter may be expected to come under stress during their working lives. Tests conducted on laboratory manufactured pieces show these alloys to have poor mechanical qualities (highly brittle) whether cold or hot-worked / annealed. Optical metallography of archaeological specimens confirms their lack of subsequent working after manufacture.
Of further interest are the existence of some weaponry such as spearheads, axes and swords which are also manufactured from these alloys, and which again, metallographically, do not show evidence of significant working. In consideration of the alloy compositions, properties and selective usage, it is argued that antimony bronze was used a material to produce bright, tarnish resistant / silvery coloured items for display / status purposes. The typological selectivity with which it occurs argues that properties of this special bronze were known, understood and deliberately chosen for during the Late Bronze Age of Central Europe.