8^th millennium BC

first use of native copper, evidence from Anatolia

5000 BC

evidence for working and casting gold from Bulgaria

4^th millennium BC

evidence for smelting in the Middle East (Jordan)

3^rd millennium BC

evidence for use of native copper around the Great Lakes

tin smelting in Anatolia

earliest evidence for iron smelting in Anatolia (sword)

late 2^nd millennium BC

deliberate steel production and heat treatment in the Middle East

iron smelting appears in northwest India

9^th century BC

iron smelting appears in China

8^th century BC

iron smelting firmly established in the Middle East and the Eastern Mediterranean, the technology spreads to Europe

5^th century BC

iron in regular use throughout Europe

iron smelting in East and West Africa

late 1^st millennium BC

brass use in the Hellenistic world, India, and beyond

metallic zinc produced in India

metallic mercury produced in India and China