The beginning of the period is sometimes called the Chalcolithic (Copper-Stone) Age, referring to the initial use of pure copper (along with its predecessor toolmaking material, stone). Scarce at first, copper was initially used only for small or precious objects. Its use was known in eastern Anatolia by 6500 BCE, and it soon became widespread. By the middle of the 4th millennium, a rapidly developing copper metallurgy, with cast tools and weapons, was a factor leading to urbanization in Mesopotamia. By 3000 the use of copper was well known in the Middle East, had extended westward into the Mediterranean area, and was beginning to infiltrate the Neolithic cultures of Europe.
