"In the fourteenth century, cowrie shells were introduced from the eastern coast as local currency, but gold and salt remained the principal mediums of long-distance trade."

"Archaeologists discovered a 2,500-year-old mural at the ancient Maya site of Calakmul located in the Yucatan Peninsula in Mexico that depicted the earliest record of an exchange of salt as a form of Maya currency between a buyer and a seller. "

Bonus clown-world content: https://www.goldback.com where they're trying to make gold into paper money! ¯_(ツ)_/¯