Beacons were artifacts that could be used to create a dimensional rift to teleport the user to their sister Gate; regardless of where the user was in the world.
The Beacons were made out of the Gate itself, so they were a limited and expensive method of transportation. Periodically, the Association of Magic would scrape some dust from the Gate and use it to create small Beacons in a form of a white or transparent glass-like crystal which would melt and crumble after a single use.
Unlike a regular Beacon, an Eternal Beacon could be used an unlimited number of times. It is a hexagonal purple crystal the size of a baton stick. It is so rare and expensive that there were less than a thousand of them in existence.