Rai Stones are large, circular stone disks used as a form of currency on the island of Yap in the Federated States of Micronesia. These stones can weigh several tons and are made from limestone, which is often quarried from nearby islands. Their value is determined by size, craftsmanship, and history, with larger stones being more valuable. The unique aspect of Rai Stones is that ownership is often transferred without moving the stones. Instead, transactions are recorded verbally within the community, making the stones a symbol of wealth and social status rather than a practical medium of exchange.