COMPOSITIONAL ANALYSIS OF SOME 1st CENTURY B.C. DACIAN GOLD BRACELETS

B. Constantinescu
R. Bugoi
V. Cojocaru
Gh. Niculescu
E. Oberlaender - Tarnoveanu

A couple of years ago, 15 Dacian bracelets were discovered in the ancient Dacian capital (Sarmizegetusa) area, obtained through illegal means. The bracelets were then sold abroad. In early 2007, 5 bracelets returned to Romania and were included in the national treasure, put on display at the National History Museum of Romania. These bracelets look like spirals and are based on the same artistic idea, are centred around the same theme. The number of spiral varies from 6 to 8. When uncoiled, some bracelets measure 2.30 m and others even 2.80 m. 4 of them weigh 1 kg each. The 5th one is lighter, weighing only 760 grams. At each end, the bracelets are decorated with 7 palm-leaf like ornaments. The ornaments are incised and richly decorated, with fir-tree motifs, having in the middle a row of dots. The palm leaf ornament is continued with a rectangular plate, with various motifs, which differ from one bracelet to another. There are no two identical bracelets. The plate is continued with a so-called "protoma", a decorative element which looks like the head of an animal ( a wolf, a snake or a dog). The bracelets also have a combination of geometrical, vegetal and zoomorphic elements, which is also found on similar Dacian silver bracelets.

Several small fragments of natural Carpathian gold - placer and primary - were studied using Synchrotron Radiation X-Ray Fluorescence (SR-XRF) at BESSY synchrotron. The goal of the study was to identify the trace elements, especially Sn, Sb and Te. The measurements were performed in air by using a 34 keV beam to excite the characteristic X-lines in Sn-Sb-Te region. We found Sn to be present in placers from Valea Arieşului and Valea Pianului, Sb in primary gold from Zlatna, Ruda-Brad, Valea Morii, Runculeţ-Straja and Pb in primary gold from Brădisor-Brad, Zlatna, Runculeţ-Straja, Valea Morii, Muşariu-Brad. These results are consistent with the geological data for Brad-Zlatna region. Micro-PIXE is a similar method, but uses protons instead of photons for characteristic X-rays excitation. Two native gold nuggets were analyzed using micro-PIXE technique at the AGLAE accelerator, Louvre Museum, Paris and at the Legnaro AN2000 microbeam facility. Using a 75 microns Cu filter to minimize the Au lines, we found Te and Sb in primary gold from Bărdişor-Brad, Muşariu-Brad (different samples from BESSY analyzed ones). The five Dacian bracelets were measured using XRF technique (Am-241 and Pu-238 sources and a portable Mo X-Ray tube used to control the homogeneity of the alloy for each bracelet). Compositions (Au-Ag-Cu) very similar to Brad region native gold (primary and placers) - but different form bracelet to bracelet - were obtained. Differences in homogeneity - especially Cu content - for each bracelet were observed. Traces of Sn and Sb were also detected. Our conclusion: native gold (mainly alluvial - placers) from Brad region, primitive metallurgy (no refined gold).

The authors are indebted to M. Radtke, E. Pernicka and A. Schmiderer for fruitful discussions and for their help in performing the experiment at BESSY.