1Faculty of Chemistry, University of Sofia, Bulgaria
2Institute of Archaeology and Museum, Sofia, Bulgaria
3Faculty of History, University of Sofia, Bulgaria
Using EDXRF the content of gold, silver and copper in 7 gold-pectorals dated to Vth - IVth century BC was determined. The concentration of gold is between 67,4 and 92,2 %. The analytical results show that the investigated archaeological finds of gold are produced using gold without intentional adding of copper because the concentration of copper is at the level of natural concentrations - in 2 samples copper concentration is below 0,001 % and in other 5 - between 0,35 and 1,15 %.
For 5 of the investigated finds the concentration of silver is between 20,1 and 32,3 %, which could be accepted as electrum. For other 2 finds the concentration of silver was 15 % and 6 %.
The chemical composition of the investigated gold-finds from ancient Thracia was compared with the known analytical data of different archaeological finds dated to other periods of Bulgaria and Europe as well as with known gold sources from Balkan region.