left|thumb|A corroded copper ingot from Zakros, Crete, shaped in the form of an animal skin (oxhide) typical in that era thumb|upright|Many tools during the Chalcolithic Era included copper, such as the blade of this replica of Ötzi's axe. left|thumb|Copper ore (chrysocolla) in Cambrian sandstone from Chalcolithic mines in the Timna Valley, southern Israel Copper occurs naturally as native metallic copper and was known to some of the oldest civilizations on record. The history of copper use dates to 9000 BC in the Middle East; a copper pendant was found in northern Iraq that dates to 8700 BC.No primary source is given in that book. Evidence suggests that gold and meteoric iron (but not smelted iron) were the only metals used by humans before copper. The history of copper metallurgy is thought to follow this sequence: first, cold working of native copper, then annealing, smelting, and, finally, lost-wax casting. In southeastern Anatolia, all four of these techniques appear more or less simultaneously at the beginning of the Neolithic .
left|thumb|A corroded copper ingot from Zakros, Crete, shaped in the form of an animal skin (oxhide) typical in that era thumb|upright|Many tools during the Chalcolithic Era included copper, such as the blade of this replica of Ötzi's axe. left|thumb|Copper ore (chrysocolla) in Cambrian sandstone from Chalcolithic mines in the Timna Valley, southern Israel Copper occurs naturally as native metallic copper and was known to some of the oldest civilizations on record. The history of copper use dates to 9000 BC in the Middle East; a c.opper pendant was found in northern Iraq that dates to 8700 BC.No primary source is given in that book. Evidence suggests that gold and meteoric iron (but not smelted iron) were the only metals used by humans before copper. The history of copper metallurgy is thought to follow this sequence: first, cold working of native copper, then annealing, smelting, and, finally, lost-wax casting In southeastern Anatolia, all four of these techniques appear more or less simultaneously at the beginning of the Neolithic .