The story of the world’s first coins, seemingly introduced in the mid-seventh century B.C. were made of electrum is well known. This alloy of gold and silver earned its name from its pale yellow color, which resembled amber, called “electron” in Greek. We know it today as Electrum. 
The most important issuer of electrum coins in the Greek world was Cyzicus, a wealthy port on the southern shore of the Bosporus, the strait that links the Black Sea with the Aegean. Its ideal location allowed the city’s merchants to grow wealthy from their near-monopoly on trade between Greece and the distant shores of the Black Sea.
The mint of Cyzicus coined electrum far later than other mints; they maintained the early incuse punches on the reverse, and the obverse was an outlet for artistic creativity. Themes included plant and animal life, and gods and heroes, always with a tuna. The symbol of the mint or the civic badge of the city.