Short answers, pulled from the story.
The word Chalcolithic combines two Greek roots: khalkos for copper and lithos for stone. This term emerged around 1900 to replace earlier labels like Eneolithic which confused scholars who thought it meant outside the Neolithic period.
A copper axe found at Prokuplje, Serbia contains the oldest securely dated evidence of copper-making from 7500 years ago. This discovery extends the known record of copper smelting by about 800 years compared to previous findings.
Mehrgarh inhabitants fashioned tools using local copper ore between 7000 and 3300 BC while four farming communities flourished in India including Ahar or Banas Kayatha Malwa and Jorwe. Copper bangles and arrowheads were found at Bhirrana the earliest Indus civilization site.
Andean civilizations appear to have independently invented copper smelting thousands of years before European contact with artifacts from Michigan and Wisconsin dating between 6500 and 1000 BC making them some of the oldest Chalcolithic sites globally.
Russia lacks a well-defined Copper Age between its Stone and Bronze Ages according to archaeological records because a five-period system conventionally used in American archaeology does not include distinct metal ages despite prior technology development.