Few systems of currency in the world are more unique and intriguing than the rai stone circles used on the tiny western Micronesian island of Yap. Carved from slabs of limestone, the donut stone circles measure up to 4 meters (12 feet) in diameter, although they come in sizes ranging from an Oreo to a cartwheel, or a van.
The stones are not actually forged on the island of Yap, where there are no metals or such stones, but come from the distant island of Anagumang, some 640 kilometers (~400 miles) away. According to one version of the origin story, the currency emerged when a band of explorers from Yap traveled to Anagumang over 500 years ago. Amazed by the wealth of limestone on the island, the people from Yap were permitted to mine and carve the limestone in exchange for goods and services to the people of Anagumang. The carved rocks were then sailed back against the ocean to Yap, which is no small feat considering some weigh more than an elephant.
This strenuous process of obtaining the rai stones enriched them with a sense of value. Like a giant coin, the rai stones are exchanged as a symbol of value during culturally important ceremonies, such as marriage, inheritance, settlement of a conflict, or a political dealing. The rai stones are still used for ceremonial exchanges today, although cash is generally used in the day-to-day life of the island.
However, given the rai stones' size and weight, they are not carried in a wallet and will typically remain immobile outside of significant spaces, like outside public buildings or communal paths. The knowledge of who owns what is recorded in a public oral tradition, with transfers of the stones being carried out in a public ceremony for all to see.
In 2019, archaeologists and economists from the University of Oregon studied this money system and argued that it bears some striking similarities to cryptocurrencies like Bitcoin.
Bitcoin is a decentralized digital currency that doesn’t require a central authority, like a bank, to process transactions. To keep track of transactions, the exchanges are encoded into a public transaction ledger, known as the blockchain, which is a bit like a shared spreadsheet that’s constantly being updated. Transactions are verified collectively by everyone within the system and all transaction histories are available for everyone to see. Since shared knowledge and communal faith in the currency is at the heart of rai stone, this team of researchers argued it’s distinctively similar to the oh-so 21st-century concept of cryptocurrency.
“As with the rai stones, information about bitcoins’ value and ownership is managed collectively; it’s a distributed financial system as opposed to the more familiar, centralized systems involving third-party financial institutions,” Stephen McKeon, an associate professor in the Department of Finance at the University of Oregon, who worked on the project, said in a statement.
“History often repeats itself, and this is a case in point. It's reasonable to infer that the Yapese model was the impetus for a digital means of doing something very similar,” added Scott Fitzpatrick, an archaeologist who led to study. “Either that, or it’s a case of cultural convergent evolution, where two temporally and geographically distinct cultures develop a remarkably similar system, which would still be pretty intriguing.”
Fundamentally, the rai stones highlight just how wispy and abstruse the idea of currency really is. Currency can be defined as anything that’s used as a medium of exchange for goods and services. In the 21st century, nations use fiat currency that has no intrinsic value — you can't eat or wear a banknote — and it’s not tied to the price of any precious commodity, like gold. It’s only valuable because it’s backed by a government and we’ve all agreed it represents value. In reality, it's all just abstract.
Just like a giant stone in the Micronesian jungle, a pack of cigarettes between cellmates, or a bag of ancient beads, our currency only has value because we've all agreed it has.