Geocoin

A geocoin is a metal or wooden coin minted in similar fashion to a medallion, token coin, military challenge coin or wooden nickel, for use in geocaching. The first geocoins were developed by Jon Stanley (aka moun10bike) as a signature item to be placed in caches.

Many of them are made to be trackable on various websites to be able to show the movement around the world and visitors to be able to leave comments when they find the coin.

A geocoin typically has a diameter of 1.5 inches (38 mm) to 2 inches (51 mm) and a thickness between 0.098 inches (2.5 mm) and 0.16 inches (4 mm). Coins with the size of 1 inch (25 mm) are called microcoins, because they fit into microcaches (e.g. film canister). The smallest geocoins with a diameter of 0.5 inches (13 mm) are called nanocoins, and have been sold since 2009. If the diameter is larger than 3 inches (76 mm) the geocoin is called macrocoin. It has the famous saying of "thats not a coin its an anchor".