In Sardinia, compared to northern Italy, there is a slight delay in the launch of the metallurgical practice, perhaps due to the dominant role played by obsidian (still well evident in the first half of the fourth millennium). Just the moment of maximum diffusion of this material also marks the beginning of metalworking.
At the end of the fourth millennium, perhaps due to the depletion of agricultural land linked to the their intense exploitation, there is a greater control of natural resources and consequent growth of territorial competitiveness; it is in this phase, therefore, that the copper processing will encourage a renewed impetus to the social and “commercial” exchanges of greater complexity.
The knowledge of metal in the Su Coddu / Cannelles site is confirmed by the discovery of small artifacts dated to the ancient Eneolithic (Sub-Ozieri). In particular, these are points andawls (needles) of copper or silver and from a fragment of copper wire. However, it is mainly thanks to the discovery of a clay crucible (terracotta) in the Canelles area, i.e. a container used for metal casting, which attests metallurgical practice.
The discovery of copper and silver smelting slag, some even attributed to Late Neolithic phase of Ozieri (the oldest), would also seem to highlight the practice of fusion metals but since some of them have not been analyzed chemically, doubts remain about their derivation from a metal smelting activity. Other slag (found in the Badas land) were instead analyzed, but the percentage of traces of metals in them would seem too low to think of any fusion activity. In fact, these slags may be the result of other activities, such as ceramic firing process where high melting temperatures are reached (even though for a short period) and therefore sufficient to create such waste residues.