On the Yap Islands of Micronesia, wealth once took the form of limestone disks with a hole in the center, some as small as a saucer and one 12 feet across and roughly 8,800 pounds. This episode explains how rai stones worked as money without ever needing to move. Ownership lived in a shared oral ledger: when a stone changed hands for a marriage, an inheritance, or a political alliance, the community simply updated its memory. One stone that sank in the Pacific during transport kept its full value because everyone agreed it was still there.

The stones were valuable because they were so hard to get. Yap has no calcite, so expeditions of young men sailed about 400 kilometers to Palau, bargained with local chiefs for quarry rights, carved the rock with clam shell tools, and towed it home on bamboo rafts. Many died along the way, and each stone’s worth reflected the hardship in its history. The episode traces what happened when an outsider with iron tools and sailing ships removed that hardship.

• Rai stones were reserved for major transactions such as sealing marriages, securing treaties between villages, and paying ransom for the return of the dead after a battle.
• Legend says early carvers tried shapes like fish, lizards, and turtles before settling on a full moon with a central hole that let men carry the stone on a log.
• After being shipwrecked near Yap in 1871, David Dean O’Keefe paid for copra and sea cucumbers with stones quarried using iron tools. The Yapese responded by valuing his stones below older ones with harder histories.
• In 1991 Milton Friedman compared the stones to gold in the Federal Reserve vault in New York, where a 1932 transfer to France consisted of relabeling bars that never left the room.
• Japanese forces destroyed many stones during World War II for runway material and boat anchors, yet surviving stones are still exchanged for important cultural events and appear on local license plates.