If you sit down for any length of time and think about it, money is weird. It doesn't take much deviation from the norm to really drive that fact home. Here are some unusual currencies, from bartered necessities to regional quirks.
10. Rai Stone
On the island of Yap in Micronesia, these enormous limestone discs are held dear. Limestone is not native to Yap - it had to be carried over from the neighboring island of Palau. At 12 feet in diameter and weighing as much as 8 tons, the price of carrying the stones to Yap was often paid in blood. Rai stones were therefore very valuable and used as ceremonial currency for enormous events such as weddings. The stones stay in place - ownership is transferred in an enormous public ceremony.