10 Cents

Marie Byrd Land is an unclaimed territory in West Antarctica — the largest such territory on Earth — and has no permanent population, no government, and no monetary system. Coins issued in its name are privately produced novelty items with no issuing authority behind them. This one is copper plated steel at 12.4 g, a weight that exceeds most legitimate 10-cent pieces by a considerable margin, which tells you something about the priorities of whoever struck it.