The currency of the Crescent Islands are eos, a pun on the initials for Extraordinaires. The citizens may trade and barter goods, but a majority of the population use eos to purchase products.

Eos are typically a mock golden color, shaped like a diamond. There is a gem on one side and a raised number representing the eo value on the other. The new version of eos, released shortly after the arrival of Brooke, are diamond-shaped and gold. A hole is in the middle so merchants can hold several on a string, and the gem is diamond-shaped and take up the whole side. The reverse side currently holds various carvings.

There are four types of eos:

Green - Represents one or five eos. It has a green gem on one side and I (One) or V (Five) on the other.

Yellow - Represents ten or twenty eos. It has a pale yellow gem on one side and X (Ten) or XX (Twenty) on the other.

Purple - Represents fifty or one hundred eos. It has a deep purple gem on one side and L (Fifty) or C (One hundred) on the other.

Red - Represents one thousand eos. Not very common. It has a brilliant red gem on one side and M (One thousand) on the other.

Lost Eos

Two eos have been created in the past, claiming to be worth plenty when they were not legitimate. Several merchants and workers have been cheated with the lost eos, now scattered around the islands in unknown areas after the announcement confirming they were fakes.

Blue - Represents five thousand eos. It has a blue gem on one side.

Orange - Represents one million eos. It has an orange gem on one side.