Precious metals and coinage

The earliest known coins were made in Lydia, a kingdom in present-day Turkey with its capital at Sardis, in the second half of the 7th century BC, in electrum — a natural alloy of gold and silver [8]. British Museum excavations at the Temple of Artemis in Ephesus found 93 of these coins deposited as offerings at the end of that century [8]. The neighboring Greek cities adopted the novelty soon afterward. A piece whose weight and purity were guaranteed by an authority solved part of the problems of transport and division.

The Romans popularized the silver denarius, which gave rise to the word "dinheiro" in Portuguese [6].

Coins reflect the mindset of a people and their era. Political, economic, technological and cultural aspects can be seen in them.

Rulers' faces on coins also became a propaganda tool. One of the best-known examples is the portrait of Alexander the Great, minted after his death (323 BC) by Lysimachus, one of his generals and successors, between about 305 and 281 BC, to present himself as the legitimate heir [9]. Since then, kings, emperors and presidents have used coins as a statement of power.