Coin currency is a type of money used in many countries. It is typically made of metal, and often features a portrait or national emblem on one side. The other side may bear the date of minting, or other types of information. In modern times, many coins have a face value greater than the material value; this is known as debasement. The practice is most common with paper money, but also occurs in some gold bullion coins and cryptocurrencies.
Historically, the value of a coin was determined by its intrinsic metal content and history. As a result, a rare or historic coin could be worth significantly more than its face value. This gave rise to the concept of rarity and beauty, as well as the practice of collecting and investing in rare or historic coins.
However, most coins today are not worth their face value. This is because the market exchange value of most coins is determined by government fiat, rather than by their valuable material or historical significance. This makes them more like tokens than true currencies (see History of money).
Most major economies that use coinage have several tiers of value, with gold coins being the most valuable and used for large purchases or state activities. Silver coins were used for midsized transactions, while copper and bronze coins were the smallest denominations. The face values of these different tiers are usually defined by the amount of precious metal in each.
In the past, coins were sometimes made of multiple precious metals, to provide a variety of trade and circulation options. For example, a coin might contain gold and silver, or two different metals such as copper and nickel. Coins of this type were sometimes called bimetallic coins. Coins of this kind are still in some circulation, including the Euro1, the British PS1 and UK 20p, and the American quarter and Canadian $2 coins.
Coins may also have a space on their surface below the main design, called the exergue. The space is often used for a date, but can be left blank or contain a privy mark, mint mark, or other decorative feature. In the past, some coins also had a milled edge, a symbol of quality and originality that was intended to prevent “shaving,” in which unscrupulous persons would shave a small amount of metal from the edges of circulating coins.
Some people enjoy searching through rolls of old coins to find ones that are worth more than their face value. This hobby is called coin roll hunting and has thousands of adherents. It can be a fun way to spend time, but it is important to remember that the odds of finding a valuable coin in any given roll are very low. For this reason, it is best to ask your bank before you start sorting and rolling your coins. Each bank has its own policies regarding coinage. For example, some banks only accept rolled or unrolled coins, or only certain coinages of higher value.