Coins have been in use as a form of money for over 2000 years. They were probably the first form of money. Coins are still used for smaller amounts of money, though paper money and non cash forms of money are used for larger payments. Coin collecting is a popular hobby. Some people specialize in collecting the coins of one country. Others collect world coins, coins from anywhere in the world.
Are there true world coins, coins that can be used as cash anywhere in the world? The standard practice is for coins to be issued in a specific currency, such as euros or US dollars. A euro coin would be usable in any country where euros are usable. This would not include all countries, so it would not be accurate to describe euro coins as world coins. The same would be true of US dollar coins.
Some currencies are not limited to the countries where they are official currency. Many stores in the eurozone will accept British pounds, for example. A world coin would have to be usable in any country in the world. The United States dollar is probably the most widely accepted currency, but even it can’t be used everywhere.
Bullion coins are a bit hard to classify. They are usually legal currency with face values, but they are typically made of precious metal with much more value than the face value. Consider the $10 American Gold Eagle coin. It has a face value of $10, but its gold content is valued at $325 (today, 7/9/2010, probably different soon).
What would happen if you tried to pay for a cup of coffee with a $5 American Gold Eagle in the United States? This would not be a very smart move. If the counter person accepted the coin as $5, you would be losing much of the value of the coin. You could almost certainly get a lot more value by selling it as gold.
Suppose you try the same thing in a Japanese grocery that does not take American currency. They could either refuse the payment or treat the coin like gold. I’m guessing that most would probably refuse it, and with those who did, you might have to haggle about the value of the gold. One of the benefits of standard currency is that it reduces the necessity for this kind of haggling. Anyway, it would be hard to consider this coin to be a world coin.
Will we ever find the true world coin that is easily used throughout the world? The real question is will we ever have a worldwide currency. If so, then world coins will surely follow.