It's interesting to see other types of money, and this one in particular is very similar to Bitcoin in the sense that there is a fixed supply of them (no more are created or imported into the island), and it is legal tender in the island.
Because these stones can be extremely difficult to move, they usually don't move them and instead they simply keep a ledger of who owns what, similar to how Bitcoin works.
Although the ownership of a particular stone might change, the stone itself is rarely moved due to its weight and risk of damage. Thus the physical location of a stone was often not significant: ownership was established by shared agreement and could be transferred even without physical access to the stone. Each large stone had an oral history that included the names of previous owners. 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 any other stone.