Metallurgy during the Copper Age in Europe

The Copper Age, also called the Eneolithic or the Chalcolithic Age, has been traditionally understood as a transitional period between the Neolithic and the Bronze Age, in which a gradual introduction of the metal (native copper) took place, while stone was still the main resource utilized. Recent archaeology has found that the metal was not introduced so gradually and that this entailed significant social changes, such as developments in the type of habitation (larger villages, launching of fortifications), long-distance trade, and copper metallurgy.

Source: Wikipedia — Metallurgy during the Copper Age in Europe (CC BY-SA 4.0)