Acorns appear on coins as a historical or symbolic designs, such as the British sixpence and three pence coin featuring acorns on an oak design.
The British sixpence and three pence coins from the early 20 century, featuring King George V included designs with an oak theme where the number of oak leaves and acorns signified the coins value.
The Gigliato, a coin from the Kingdom of Naples, also featured acorns in the obverse field as part of the design during the reign of Robert of Anjou from 1309-1343. In recent years the United States Mint has featured oak themed designs, on the American Eagle Platinum Proof Coins with some showing acorns on a branch.
Many companies sell “Mighty Acorn” coins or similar tokens, often made of pewter. They are sold as inspirational or good luck charms.