Which island in the Pacific uses doughnut shaped coins made of stone?

Yap or Wa′ab traditionally refers to an island located in the Caroline Islands of the western Pacific Ocean, a part of the Federated States of Micronesia. The name "Yap" in recent years has come to also refer to the state within the Federated States of Micronesia, inclusive of the Yap Main Islands and its various outer islands.

Yap is known for its stone money, known as Rai, or Fei,: large doughnut-shaped, carved disks of (usually) calcite, up to 4 m (12 ft) in diameter (most are much smaller). The smallest can be as little as 3.5 centimetres (1.4 in) in diameter. Many of them were brought from other islands, as far as New Guinea, but most came in ancient times from Palau. Their value is based on both the stone's size and its history. Historically the Yapese valued the disks because the material looks like quartz, and these were the shiniest objects available. Eventually the stones became legal tender and were even mandatory in some payments.