Content area
Full Text
Abstract:
The problem of counterfeit coins exists in many countries. Until 1995, coins from Israel were a single color and were easily duplicated. In 1995, the Bank of Israel issued a new Israel shekel 10 coin that was intended to reduce the likelihood of counterfeiting. After the initial distribution of the new coins, counterfeits soon appeared. This report describes the various processes used to produce counterfeit coins.
Introduction
Coins are metallic and, most often, round. Usually, coins also contain an imprint with the country's name, the coin's value, and an illustration.
In ancient times, ingot metals (e.g., gold, silver, and copper) were used in coins. This was the case with Greek coins used as early as the 7th century B.C.E. (Before the Common Era) [1]. Later, the Greeks started using low-value bronze coins as early as the 5th century B.C.E. Athens struck silver coins from at least the 5th century B.C.E. It is also known that the Jewish temple taxes were paid in shekels struck by the Phoenicians' city of Tyre. The common method of counterfeiting gold and silver coins was to shave the edge of the coin. Coins with grooved edges were then introduced to prevent this type of counterfeiting. Until 1914, casting was the most common process used to produce coins. It was a time-consuming process and unique to each coin. Most of the coins were made using gold and silver [2, 3, 4]. The relatively high value of these coins made them impractical in the market place, and they never really replaced the barter system. In 1914, governments began to mint low-value bronze coins produced by a cold or hot nonelastic (plastic) process [5]. The minting is done with high pressure for a short time, with no need for a finishing process.
Minted Coins: Practical Aspects
In coins that have been produced since 1914, one of two pressing processes is used in minting:
(1) A moving die is pressed against a blank on a static die. This process is used to mint coins with a one-component material. Die configuration is in a "pestle and mortar" shape. One die has the mold of the "value" of the coin and the other die has the "subject" mold of the coin. After the...