A pattern coin is a coin which has not been approved for release, produced for the purpose of evaluating a proposed coin design. They are often off-metal strike, to proof standard or piedforts. They are collected or studied by many coin collectors because of their sometimes highly elaborate designs.
The first English coin that can be identified with certainty is a groat, originally worth fourpence. This piece, an example of which was illustrated and sold in the Dodsley Cuff sale of the mid-19th century, had crowns in place of the usual three pellets in each quarter of the reverse.
Patterns are particularly identifiable and exist in larger numbers from the reign of Elizabeth I onwards. The experimental base metal issues of all coinage prior to the mid-18th century have been well preserved.
Boulton's mint in Soho produced prodigious quantities of patterns, which were supplemented by Taylor some fifty or so years later from the same dies.
After the Declaration of Independence was signed on July 4, 1776, discussion arose over what sort of currency should be adopted in the United States. During the next 16 years, a variety of different coin designs from over the world were common. In this period, a relatively large amount of different pattern coins were created, proposed for use in the newly found states. However, none of these designs were used by the general public.
In 1792 the United States Mint opened in Philadelphia. In that year several more patterns were created, including the half dime, then known as a "half disme". It is believed that ca. 1,500 pieces were struck as patterns, and that these patterns themselves entered circulation during the next decade.
Over the next 40 years, more patterns were created but there is little information currently known about these pieces. Technically, these coins were not patterns but rather off-metal strikes, with the coins struck in a different metal than those destined for general use in circulation. An example is an 1807 Half Eagle, or five dollar gold piece struck in copper.