Ancient Coins

• Slaves hammered the earliest coins from electrum, a gold and silver alloy. Greeks distributed these coins, which usually displayed images of their gods. Each city had its own patron deity. The coins minted in that city reflected such patronage. For example, Athens minted coins with images of owls, the goddess Athena's symbol. Coins from the city of Knidos depicted lions for Apollo.
  
  Roman coinage was first minted in bronze. Silver coins, called "denarius," were later added. These bore the images of Roman generals and emperors, such as Julius Caesar.
  
  

The Euro

• Conversion to the euro, Europe's international currency, marked the most sweeping money changeover in history. It replaced several well-known currencies, including the German mark, the French franc and the Italian lira.
  
  The euro comes in both paper and coin currency. Every euro coin bears the familiar "€" on the front, but each country creates their own design for the reverse side.
  
  

Unique Coins

• Canada unveiled a coin in 2007 with a face value of $1 million. It is the size of a jumbo pizza and weighs 100 kilograms (220.4 lbs.), and has a maple leaf on one side and an image of Queen Elizabeth II on the other.
  
  Somalia is known for issuing unusual coins. Their mintage includes money in the shape of cars, guitars, wildlife and 3-D geometric designs. Other unusual coinage includes a "television" coin from the Cook Islands, with a moving television image embedded into the coin.
  
  

Animal Motifs

• Animals are the most common motifs on world coins. A few that have graced coins within the past several decades are the antelope (Central African States); bear (Finland); camel (Sudan); cow (Italy) and crocodile (Jamaica). Ireland and Canada display deer on their recent coins and both Chinese and Icelandic coins depict dragons. More animal portrayals include a snake (Mexico); tiger (Singapore); owl (Greece); and dog (Ireland).
  
  

Commemorative World Coins

• Commemorative coins are issued by nearly every country and honor a specific event or person. Noted examples for 2009 include one from the United States and two from Australia.
  
  The Louis Braille bicentennial dollar honors the 200th anniversary of Louis Braille's birth. The coin bears raised Braille lettering and honors the man who created the Braille language for the blind.
  
  The "Polar Series" of coins, from the Royal Australian Mint, promotes awareness of global warming and the effect that the shrinking polar ice cap incurs on the rest of the world.
  
  Galileo's construction of a telescope is honored in coin form from Perth, Australia. It celebrates the "International Year of Astronomy" and marks the 400th anniversary of Galileo's telescope.