If tetartemorion sounds like a mouthful – it was. Fifth-century BC Athenians found most silver coins so minute and easy to lose they resorted to carrying them in their mouths. They were eventually replaced 200 years later by copper coins, which made low-value transactions easy to handle. And they were stamped with designs that became an early form of mass communication. More than 500 of those copper coins have gone on display this week at the private Benaki Museum in central Athens. The two-month exhibition is aimed at highlighting the allure of the humble monetary form from ancient Greek cities – the first to use copper coinage – and medieval Byzantium. «Large quantities of copper coins turn up during archaeological excavations,» said exhibition curator Vassiliki Penna. «They don’t shine, they are not golden, and time corrodes them. But they carry a patina of charm – the charm of everyday life.» Because of their wide distribution through ancient and medieval social classes, Penna said, low-denomination copper coins were used by rulers as means of religious or political propaganda, and served as «a kind of news medium.» Rulers produced coins decorated with their faces, while cities used them to back up historic or mythological pretensions; Smyrna – modern Izmir in Turkey – which claimed to be Homer’s birthplace, issued coins picturing the writer of «The Iliad» and «The Odyssey.» «Copper coins were very useful for spreading messages, symbolism or political theories,» said Penna, a historian and numismatologist at the University of the Peloponnese. «In ancient times, while the representations on gold and silver coins did not change frequently, rulers struck a lot of different copper coins, renewing the iconography, to convey messages to the masses.» And silvers could be so small: Tetartemorion was the lowest denomination and weighed just 0.16 grams (0.01 ounce). Aristophanes made fun of their inconvenience in his comedies, and Plato, another contemporary, had long urged Athens to replace its unwieldy silver currency. While the first coinage in history – made of electrum, an alloy of gold and silver – was struck just before 600 BC by Lydian and Greek rulers in what is now Turkey, copper coins took nearly another century to catch on. The first examples were produced by ancient Greek trading colonies in the Black Sea, such as Olbia and Istria, and looked nothing like other ancient – or modern – coins. They were shaped like dolphins, lance heads or leaves. The new currency soon caught on in the Greek colonies of southern Italy, became conventionally rounded and eventually reached the mainland.