Chemical composition analyses of new raw copper hoards from South Bohemia A contribution to the metallurgy of the Early Bronze Age

This work has studied elemental composition of raw copper contained in recently excavated hoards from Early Bronze Age in Southern Bohemia. The analyses were applied to hoards from Pridoli, Purkarec, Chvalsiny, Kladne-Zhorkov and two finds from Nova Ves near Kremze. In addition, also an older hoard found at Nove Vrato (in 1964) was analyzed. The hoards contained ingot torques, ribs and formless fragments of plane-convex ingots of raw copper. Together with torques from Nova Ves two spiral armrings were found; with pigs of Kladne an axe fragment and dagger blade; with fragments from Nova Ves an axe of Krtenov type. Based on statistical evaluation of composition of ingot torques analyzed here and completed by approximately further 2700 analyses from Central Europe a hypothesis is presented that material of ingot torques could be prepared by smelting pure chalcopyrite ore. The high arsenic, antimony and silver contents were a result of intentional alloying of pure copper with tetrahedrite minerals. A quite atypical material is represented by ribs from Purkarec containing an alloy of copper with very high contents of lead.