
On the observe of the coin are depicted the heads of a lion and a bull facing each other.
Precious metals were exchanged by weight from the earliest times but only became "money" when the seal of a recognized authority was impressed on a few small ingots of agreed weight and alloy, making it possible to exchange them by number rather than by weight and rendering the use of scales unnecessary.
Herodotus attributed this development to the Lydians, who minted coins in gold and silver. Croesus, the last king of Lydia, is credited with the creation of a bi-metallic monetary system based on gold and silver coins (Croeseids) linked by fixed value ratios.
When the sacred area dedicated to Artemis was being excavated at Ephesus several small disc-shaped lumps in electrum, buried at the time of Croesus, were found (completely unmarked metal lumps, discs with striations or punch marks, discs with figures and inscriptions). They are of immense historical interest as they document the very beginnings of the circulation of coinage in Asia Minor.