Coins in Movies: "The Luck of the Irish" (1948) with Tyrone Power.
I watched the film "The Luck of the Irish" on television several times when I was a kid, sometimes with my father who was into Irish-related films.
The film is on DVD now and I watched it recently, and found that there was a coin involved in the story.
While visiting Ireland, American newspaper reporter Tyrone Power meets a Leprechaun who gives him a gold coin as a "lucky coin".

Later local girl Anne Baxter identifies the coin as a Spanish Doubloon, sixteenth century, from the (1588) Armada wreckage.
The coin is shown, it is, of course, an imitation prop coin.

The coin is apparently based on an old Spanish coin of King Ferdinand.
The legend reads "NAVARRE" and "FERNANDVS".
After Tyrone returns to New York, he makes a couple of bad decisions, and the coin turns into a pebble.
There is more on my website under "Coins in Movies".
