A Rune of Teleportation is a player made tool that creates a portal to an active Teleport Stone. It is made with 2 Sigma Fragments, and requires a Workbench.
When the player uses a Rune of Teleportation, a portal is created where the player stands. The other portal will appear above an active Teleport Stone. Only one stone can be active at a time. The portal will stay open for 5 minutes, and can be made anywhere aside from NPC built structures, like the Settlement. The portal can be used by standing near it and pressing the action key.
Active Teleport Stone and Portal.