coin
Coinage is a currency form, which is one of the common forms of coinage in today's world. Craftsmen are often prepared in advance according to the design style, using metal, smelting, casting, molding, handmade, mold making, batch turning, casting, grinding, etc .; using a variety of metal raw materials, mainly gold, silver, Lead, tin, nickel, aluminum, zinc and so on. Different kinds of metal raw materials smelting methods, made of gold coins, silver coins, coins, lead coins, aluminum coins, nickel coins several categories. These categories can be based on different appearance, sub-dozens of categories. Coin shape has perforated plate currency, ingot currency, solid plate currency. There are written records since thousands of years ago, the day of coins generated, at the same time with the corresponding era. From the coin can be more long-term preservation of the times of information, which also produced a variety of commemorative coins; before the emergence of paper money, coinage is the main form of money. Precious metals such as gold and silver casting coin called gold or silver coins, you can directly into the field of financial exchange, to achieve currency exchange. ...