Coinage shapes
Coins by shape
Although the vast majority of coins are circular due to their origin as flattened pieces of metal forged between tongs, coins are made in a variety of other shapes, including squares, diamonds, hexagons, heptagons, octagons, decagons, and dodecagons. They have also been struck with scalloped (wavy) edges, and with holes in the middle. Coins in the shape of polygons often have rounded edges or are Reuleaux polygons.
This article focuses mainly on circulating coins; a number of non-circulating commemorative coins have been made in special shapes, including guitars, pyramids, and maps. There is a list with more unusual shapes of non-circulating commemorative coins at the end of this page that all have been issued officially by various countries.
Triangular
The Cook Islands have a circulating 2 dollar triangular coin with rounded corners.
A triangular coin with a face value of £5 was commissioned by the Isle of Man to commemorate the 2007–2008 Tutankhamun exhibition at The O2 Arena in London. It became legal tender on 6 December 2007, but it was rarely used because each coin cost £15 to purchase from the Isle of Man Post Office.
Other triangular coins issued earlier include: Cabinda coin, Bermuda coin, Uganda Millennium Coin and Polish Sterling-Silver 10-Zloty Coin.
Squares and diamonds
Indo-Greek coins were often square.
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This entry incorporates text from “Coinage shapes” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.