Making money is never easy but on the South Pacific island of Yap it used to be very dangerous, difficult work!

Although the Yapese people usually spend U.S. dollars, their traditional money, the Rai, is actually made of stone. Measuring up to 3.6 metres in diameter, and weighing up to 4 tonnes, this disk-shaped "stone money" is still used for weddings and the sale of land.

The special crystalline stone used for the rai cannot be found on Yap itself. The Yapese instead travelled 480 kilometers to another Pacific Island, Palau. There they used simple tools to hack (cut) the stone and load it onto their canoes for the long trip back. How much is one rai worth? The bigger the coin, the greater its value, but the shape, quality and texture of the stone also affect its value. Most important, though, is the effort in getting it. The journey to and from Palau could involve storms, shipwrecks, shark attacks, and men often lost their lives in bringing the stone home. All of these increase the value of the coin.

In the 19th century, an Irish-American captain named David O'Keefe went into business with the Yapese people. He used his ship to carry the special stone from Palau to Yap and traded it for copra and sea cucumber. Although people liked the safety and convenience, the "O'Keefe money" was not as valuable as the rai brought by canoe.

"Banks" are found in villages all over Yap, but people rarely take money out of them. When a giant coin is spent, the news spreads, and soon everyone knows that the money has a new owner. Although stone money is very hard to get, it has one big advantage: it is impossible to steal or lose!