technique of minting coins arrived in mainland Greece around 550 BC, beginning with coastal trading cities like Aegina and Athens. Their use spread and the city-states quickly secured a monopoly on their creation. The very first coins were made from electrum (an alloy of gold and silver), followed by pure silver, the most commonly found valuable metal in the region. The mines of the Pangaeon hills allowed the cities of Thrace and Macedon to mint a large number of coins. Laurium's silver mines provided the raw materials for the "Athenian owls", the most famous coins of the ancient Greek world. Less-valuable bronze coins appeared at the end of the 5th century. Coins played several roles in the Greek world. They provided a medium of exchange, mostly used by city-states to hire mercenaries and compensate citizens. They were also a source of revenue as foreigners had to change their money into the local currency at an exchange rate favourable to the State. They served as a mobile form of metal resources, which explains discoveries of Athenian coins with high levels of silver at great distances from their home city. Finally, the minting of coins lent an air of undeniable prestige to any Greek city or city-state. Shopping The shopping centres in Ancient Greece were called agoras. The literal meaning of the word is "gathering place" or "assembly". The agora was the centre of the athletic, artistic, spiritual and political life of the city. The Ancient Agora of Athens was the best-known example. Early in Greek history (18th century–8th century BC), free-born citizens would gather in the agora for military duty or to hear statements of the ruling king or council. Every city had its agora where merchants could sell their products. There was linen from Egypt, Ivory from Africa, Spices from Syria, and more. Prices were rarely fixed, so bargaining was a common practice. See also Slavery in Ancient Greece Roman economy Economy of Greece Notes Sources Bresson, Alain. The Making of the Ancient Greek Economy: Institutions, Markets, and Growth In the City-States. Expanded and updated English edition. Translated by Steven Rendall. Princeton: Princeton University Press, 2015. Donlan, Walter. "The Homeric economy." In A new companion to Homer, edited by Ian Morris and Barry B. Powell, 649-67. New York: E.J. Brill, 1997. Finley, Moses I. The ancient economy. 2d ed. Sather Classical Lectures 48. Berkeley: Univ. of California Press, 1985. Foraboschi,