|Pottery found at Ramakkalmedu
The finding of copper beads, used for ornament, in Megalithic burials of Ramakkalmedu (Kerala) reinforces the idea of India also having a Chalcolithic period, intermediate between Neolithic and Iron Age. Until recently however the paradigm was one of Neolithic being directly followed by Iron Age.
Anyhow, in Europe often the notion of Chalcolithic, rather than just usage of copper and other soft metals (gold, silver), implies more the growth of social complexity and the first stages of civilization (much like Neolithic doesn't anymore mean the use of polished stones but farming instead).
Whatever the criteria used (not all authors agree), the beads excavated in Kerala are fine quality jewelry, and seem to imply a gradual advance of the Chalcolithic from the Deccan Plateau and ultimately from the Harappan civilization of the Northwest.
Source: The Hindu.