The key role of zinc,tin and lead in copper-base objects from medieval Talgar in Kazakhstan

Metallurgical examination of brass and bronze objects from the medieval (AD 9th–13th century) site at Talgar in Kazakhstan shows that they were mostly cast from the quaternary copper–zinc–tin–lead system with some exceptions that were forged from binary copper–zinc alloys. Evidence is found that brass was produced in the cementation process and that the addition of tin and lead to the parent brass was considered beneficial in casting but was strictly avoided in forging. The mutual effect of zinc, tin and lead for better casting and the advantages of the binary copper–zinc alloys in forging seem to have been the major factors driving the establishment of this unique brass tradition in a society with probably limited access to tin.