5 Markkaa 1946 struck on 1928-40 Copper-Nickel Markka Planchet

A rare error. The last production year of the copper-nickel markka was 1940, but somehow this 1946 5 Markkaa was minted on the copper-nickel planchet. It is common for this 5 Markkaa to be struck in iron by mistake, but not in a copper-nickel alloy.

Metal analysis shows 23% nickel and 76% copper. Weight 3.83g. Same as the 1928-40 copper-nickel markka.