The indigenous people on Yap Island in the Pacific Ocean used money called rai stones.
太平洋雅浦岛上的土著人用的货币叫做雅浦岛石币。
PBS趣味科普
Anyway, seriously, count your gold or your silver, or your Benjamins, or maybe even your rai stones if we have any fans from the Pacific island of Yap.
Rai, or stone money (Yapese:raay), are large, circular stone disks carved out of limestone formed from aragonite and calcite crystals. Rai stones were quarried on several of the Micronesian islands, mainly Palau, but briefly on Guam as well, and transported for use as money to the island of Yap. They have been used in trade by the Yapese as a form of currency.