The discovery of copper isn't attributed to a single person; rather, it was a gradual process of discovery and utilization by various ancient cultures.
The earliest evidence of copper use dates back to around 9000 BC in the Middle East, where copper tools and decorative items have been found. Specifically, the early Mesopotamians are credited with harnessing the full potential of copper metal. They developed techniques for smelting and working with copper, leading to its widespread use. Therefore, it's more accurate to say that multiple ancient civilizations independently discovered and developed copper metallurgy.
In summary, the "discovery" of copper was a long process, and it's impossible to pinpoint a single individual or group. Early civilizations, particularly in Mesopotamia, played a crucial role in understanding and utilizing this metal.