Vannoccio Biringuccio's Soldo

Origin
Vannoccio Biringuccio was an Italian metallurgist who published a manual on metalworking, De la pyrotechnic. It details many portions of the foundry and mining trade at the time, including mineral identification, smelting, forming alloys, casting, refining ores and even alchemy. Biringuccio used these coins to pay his workers in the late 15th century to motivate them into furthering his mining operations. They found little silver, but the large amounts of copper and iron made him ever richer.

Effects
A series of silver coins that, when given to a person, makes them intent on digging for silver. Any other metals they encounter will turn into some unusable alloy or become melted beyond usefulness.