1. Rai Stones - In Yap, Micronesia, massive limestone discs up to 12 feet in diameter were used as currency, despite being immovable and difficult to transport.
3. Cowrie Shells - Once widely used in Africa, Asia, and the Indian Ocean region, these small, shiny shells were valued for their beauty and rarity.
2. Wampum - Native American tribes used beads made from clamshells as a form of currency and for ceremonial purposes, representing wealth and power.
4. Katanga Cross - In the Katanga region of Congo, these large copper crosses were used as a form of currency due to their intricate designs and craftsmanship.
5. Spade Guineas - In the 18th century, the British used playing cards with a spade symbol stamped on them as emergency currency during a shortage of coins.
6. Porcelain Coins - In China during the Ming and Qing dynasties, small circular porcelain pieces with square holes in the center were used as money.