The item is always usuable by the house owner, as well as others if permissions are set appropriately.
Double clicking the crystal portal will pop open a book which provides instructions on how to use it, provided the player's account is at least 12 months old. Strangely, anyone can use the portal regardless of account age.
For traveling to the Trammel, Malas, Tokuno or Ter Mur ruleset you simply say "dungeon" followed by the name of the Dungeon you want to go to. (eg. dungeon covetous)
For traveling to the Felucca ruleset you have to say Fel before the "dungeon" and the name of the Dungeon you want to go to.(eg. fel dungeon covetous)
