One of the more interesting types of coin collection is collecting the Bi Metallic coins. A Bi Metallic coin is one that has more than one alloy or metal. They are normally constructed with an outer ring around a contrasting center metal interior.
Bi Metallic coins have been around for a long time, and the first ones were thought to be made in the 1600’s. The Roman Empire issued medallions for special occasions that had a center of one type of metal with an outer ring of a different metal.
Some people like to collect specialty Bi metallic coins, some modern examples are the one and two pound British Coins, the Canadian $2 coin, and the South African R5 coin. The United States produced a two metal coin as early as 1792 with the silver center penny.
The first bi metallic coin in modern circulation was thought to be the Italian 500 lire coin that was issued in 1982. The nation of Thailand has a 10 baht coin that it issued first in 1988, France has a coin for 10 francs that is made of bi metallic construction.
In some countries bi metallic coins are reserved for high denomination coins, and many countries use bi metallic coins for commemorative or special occasion coins and to help prevent such special coins from being counterfeited.
The process of making or minting Bi metallic coins is similar to regular minting except that it involves using two blanks, the outer and the inner and they are struck often at the same time using a pressure and stamping system that deforms each of them enough to hold them together.
Collecting Bi Metallic coins can be very rewarding, but it is a type of coin collecting that can be expensive, especially for a collection of any size.