Purple goblin mail is made by using purple dye on goblin mail. Like all goblin mail, it is too small for players to normally wear as armour.
However, during the Land of the Goblins quest, the player can turn into a goblin using a transmogrification potion to access the tribal areas of the Goblin Cave. While wearing purple goblin mail, the player can enter the Horogothgar goblin tribe's area and pickpocket the Horogothgar priest to obtain the Horogothgar key , which is required to continue the quest.
Purple goblin mail cannot be traded, and therefore has no value. It can only occupy space in the inventory or bank. However, the dye and the goblin mail are tradeable.