Potin

Potin is a base metal alloy used in coins. It is typically a mixture of copper, tin and lead (in varying proportions) and does not typically contain significant precious metals. Potin is usually used in reference to Celtic coinage.

In Celtic coinage
In 1890, so-called Potin lumps were found, of which the largest weighs 59.2 kg, at the Prehistoric pile dwelling settlement Alpenquai in Zürich (Vicus Turicum) in Switzerland. The pieces consist of a large number of fused Celtic coins, which are mixed with charcoal remnants. Some of the about 18,000 coins originate from the Eastern Gaul, and others are of the Zürich type, that were assigned to the local Helvetii, which date to around 100 BC. The find is so far unique, and the scientific research assumes that the melting down of the lump was not completed, therefore the aim was to form cult offerings. The site of the find was at that time at least 50 m from the lake shore, and probably 1 m to 3 m deep in the water.

Kentish cast bronzes (historically referred to as Thurrock potins) appear to have been the first coins made in Britain dating from the end of the second century BC. They appear to have circulated mainly in Kent and were based on coins issued by Massalia (now Marseille).