Stone Money Bank

There's a tiny island called Yap out in the Pacific Ocean. Economists love it because it helps answer this basic question: What is money?

There's no gold or silver on Yap. But hundreds of years ago, explorers from Yap found limestone deposits on an island hundreds of miles away. And they carved this limestone into huge stone discs, which they brought back across the sea on their small bamboo boats.

It's unclear if these stones started as money. But at some point, the people on Yap realized what most societies realize. They needed something that everyone agrees you can use to pay for stuff.

And like many societies, the people of Yap took the thing they had that was pretty — their version of gold — and decided that was money.

A piece of stone money was valuable; you wouldn't use it for some everyday purchase. You'd use it for something big — a daughter's dowry, say.

"If somebody was in real dire straits, and something happened to their crop of food or they were running low on provisions and they had some stone money, they might trade," says  an anthropologist at North Carolina State University who is an expert on Yap.

One key thing about this money: It was really heavy. A big piece could weigh more than a car.

As a result, this very concrete form of money quickly made the jump to being something very abstract.

"They often talk about the stones themselves not changing hands at all," Fitzpatrick says. "In fact, most of the time they wouldn't."

So, imagine there's this great big stone disc sitting in a village. One person gives it to another person. But the stone doesn't move. It's just that everybody in the village knows the stone now has a new owner.

In fact, the stone doesn't even need to be on the island to count as money.

They would use this money to make purchases but they didn't move the money.

There is money on both sides of this street and it is called the Stone Money Bank.

The Brimhall's are senior missionaries on Yap.

We are standing next to the largest stone money.