Kissi pennies were an iron currency produced by the Kissi people of Sierra Leone, and widely circulated in Sierre Leone, Liberia, and Guinea (but as a result of trading, they saw wide circulation in West and Central Africa). These Kissi pennies vary in length (from 15-40 centimetres), and becaused of their low value, they were often gathered into bundles, with a group of twenty being typical. The exact date starting date of production is uncertain, although there is no reason to believe they were made before the 1880s. As Europe colonized Africa and began introducing colonial coins, these Kissi pennies were phased out, although they continued to circulate until the 1940s in Sierra Leone (and even as late as the 1980s in Liberia). Even after being discontinued as currencies, these Kissi pennies had been made a symbol of the region, serving as tokens in various rituals (including spiritual ones). These pennies are said to channel the souls of the dead, and as such, are placed on tombs and graves. It was thought that, if one broke, it went without value until a Zoe repaired it in a special ceremony. See also: https://en.wikipedia.org/wiki/Kissi_penny