Gold has been known since prehistoric times and was one of the first metals to be worked, mainly because it was to be found as nuggets or as particles in the beds of streams. Such was the demand that by 2000 BC the Egyptians began mining gold. The death mask of Tutankhamen, who died in 1323 BC, contained 100 kg of the metal. The royal graves of ancient Ur (modern Iraq), which flourished from 3800 to 2000 BC, also contained gold objects.
The minting of gold coins began around 640 BC in the Kingdom of Lydia (situated in what is now modern Turkey) using electrum, a native alloy of gold and silver. The first pure gold coins were minted in the reign of King Croesus, who ruled from 561–547 BC.