The Micronesian island of Yap is known for its stone money, known as Rai, or Fei: large doughnut-shaped, carved disks of calcite, up to 4 m in diameter. The smallest can be as little as in diameter. There are around 6,000 of the 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 to Yap for use as money. They have been used in trade by the Yapese as a form of currency. The monetary system of Yap relies on an oral history of ownership. In the case of stones that are too large to move, buying an item with one simply involves agreeing that the ownership has changed. As long as the transaction is recorded in the oral history, it will now be owned by the person to whom it is passed and no physical movement of the stone is required.
Form and value
Rai stones are circular disks with a hole in the middle. The stones vary widely in size. The largest are in diameter and thick and weigh. The largest rai stone is located on Rumung island, near Riy village. Smaller rai stones might have a diameter of from. The extrinsic value of a specific stone is based on not only its size and craftsmanship, but also its history. If many people—or no one at all—died when the specific stone was transported, or a famous sailor brought it in, the value of the rai stone increases by reason of its anecdotal heft. Rai stones were, and still are, used in rare important social transactions, such as marriage, inheritance, political deals, sign of an alliance, ransom of the battle dead, or, rarely, in exchange for food. Many of them are placed in front of meetinghouses or along pathways. The physical location of the stone is often not significant. Although the ownership of a particular stone might change, the stone itself is rarely moved due to its weight and risk of damage. The names of previous owners are passed down to the new one. In one instance, a large rai being transported by canoe and outrigger was accidentally dropped and sank to the sea floor. Although it was never seen again, everyone agreed that the rai must still be there, so it continued to be transacted as genuine currency. What is important is that ownership of the rai is clear to everyone, not that the rai is physically transferred or even physically accessible to either party in the transfer. In this, the rai stone monetary system can be thought as an early example of a distributed ledger, similar to those used in modern days blockchain technology.
History
Yapese quarried the limestone rocks from the islands of Palau and took them to Yap with canoes and rafts. There is evidence that some limestone has been mined in Palau by Yapese as early as 500 AD, but more widespread mining started in the time period of 1000–1400 AD. Local legend holds that the Yapese discovered the rock of Palau about 500–600 years ago when an expedition led by a man called Anagumang landed on Palau. Limestone was nonexistent in Yap and therefore very valuable to the Yapese. First Anagumang ordered his men to cut stone into the shape of fish but eventually a circular shape was chosen, probably because it was easier to transport. A pole was put through the hole in the center of the stone so that laborers could carry the stone. The largest of the disks probably needed hundreds of men to transport. Residents of Palau in turn required Yapese to pay in beads, coconut meat and copra or in the form of services for the privilege of quarrying. It is unknown how long money stones have been used in Yap. Flat rocks have been found there that are up to 2000 years old, but the oldest do not resemble today's rai stones, and it is not known if they were used as money. It is nevertheless clear that the size of the stones grew sharply after European techniques and traders came to Yap. The stones may have evolved from smaller carved beads. In 1871, the Irish-American David Dean O'Keefe was shipwrecked near Yap and was helped by the natives. Later, he assisted the Yapese in acquiring rai and in return received copra and trepang, which were valuable exports in the Far East. O'Keefe provided the Yapese with iron tools. As a result, a form of inflation set in and rai stones acquired with his help were less valuable than more ancient ones. The book His Majesty O'Keefe is the story of his life on Yap. A film of the same name starring Burt Lancaster was made in 1954. The trade for rai stones eventually stopped at the beginning of the 20th century due to trade disputes between Spanish and German interests in the area. Quarries were abandoned. When Imperial Japanese forces took over Yap during World War II, they used some of the stones for construction or as anchors. Economist Milton Friedman has compared the monetary role of the stone money to the reserves of gold held in Fort Knox for foreign governments. Although modern currency has replaced the stones as everyday currency, the rai stones are still exchanged in traditional ways between the Yapese. They are a national symbol and are depicted on local license plates.
