An intermediate period between the Neolithic and the Bronze Ages, characterized by the use of copper tools. According to the principles of the Three Age System, it should strictly mean the period when copper was the main material for man's basic tools and weapons. It is difficult to apply in this sense as copper at its first appearance was very scarce, and experimentation with alloying seems to have begun early on. The alternative names of Chalcolithic and Eneolithic imply the joint use of copper and stone. In many sequences, notably in Europe and Asia, there is a period between the Neolithic and Bronze Age, separated from each by breaks in the cultural development, within which copper was coming into use and Copper Age is the best term to use. In Asia, the age saw the origins of civilization, and in Europe the great folk movements of the beaker and corded ware cultures, and perhaps the introduction of the Indo-European languages. The period lasted for almost 1000 years in southeast Europe, from 3500 BC.