Beyond the Great Wall: Gold of the Silk Roads and the First Empire of the Steppes

Abstract

Fingerprinting ancient gold work requires the use of nondestructive techniques with high spatial resolution (down to 25 μm) and good detection limits (micrograms per gram level). In this work experimental setups and protocols for synchrotron radiation induced X-ray fluorescence (SRXRF) at the BAMline of the Berlin electron storage ring company for synchrotron radiation (BESSY) in Berlin for the measurement of characteristic trace elements of gold are compared considering the difficulties, shown in previous works, connected to the quantification of Pt. The best experimental conditions and calculation methods were achieved by using an excitation energy of 11.58 keV, a silicon drift chamber detector (SDD) detector, and pure element reference standards. A detection limit of 3 μg/g has been reached. This newly developed method was successfully applied to provenancing the Xiongnu gold from the Gol Mod necropolis, excavated under the aegis of the United Nations Educational, Scientific and Cultural Organization (UNESCO). The composition of the base alloys and the presence of Pt and Sn showed that, contrary to what is expected, the gold foils from the first powerful empire of the steppes along the Great Wall were produced with alluvial gold from local placer deposits located in Zaamar, Boroo, and in the Selenga River.

A multi-analytical approach to gold in Ancient Egypt: Studies on provenance and corrosion

“…For this reason, the identification of PGEs in a gold alloy is usually identified by determining the trace elements of the gold alloys (for example [18][19][20][21]). Elemental analysis of the more soluble PGEs in gold alloys is difficult to carry out because of their atomic number, as Pt and Pd are very close to the major elements of the gold alloys, respectively Au and Ag.…”

“…Elemental analysis of the more soluble PGEs in gold alloys is difficult to carry out because of their atomic number, as Pt and Pd are very close to the major elements of the gold alloys, respectively Au and Ag. Attempts were made to solve this problem for X-ray Fluorescence (XRF) by various approaches, using different excitation energies and data processing strategies [18,19,21].…”

Fast mapping of gold jewellery from ancient Egypt with PIXE: Searching for hard-solders and PGE inclusions

“…In the case of other civilisations, the presence of Pt in gold [18][19][20][21] and the presence and composition of PGE inclusions [22] has been used with success for gold provenancing. However, the PGE mineralogy of Egypt is not very well known, in spite of the identification of Os-rich and Os-Ir alloy minerals in the Eastern Desert [23].…”

“…The PGE compositions published by Meeks and Tite [15], Troalen et al [4], and Miniaci et al [8] show that Pt is barely observed which could indicate either a lack of sensitivity of the analytical technique or, which might be our case, the use of gold from different sources. We must remark the difficulties connected to the measurement of Pt in an alloy containing high concentrations of Au [21,10] …”

Studies on ancient silver metallurgy using SR XRF and micro-PIXE

“…The Synchrotron Radiation X-Ray Fluorescence (SR XRF) investigation was performed at the BAM-line at the Helmholtz Centre Berlin for Materials and Energy HZB -BESSY II synchrotron facility (Radtke et al 2013, Reiche et al 2006. The excitation-energy of 20 keV and a beam size of 100x100µm 2 were used.…”