The Brooch is an item that is obtained during The Lost Tribequest. Players can find it at the first fork of the Lumbridge Castle cellar caves, heading towards the Dorgeshuun Mines. It does not have a respawn time—it immediately appears on the ground right after one is taken.
Having obtained the brooch, players must bring it to Duke Horacio. After looking through the Goblin book, the player realises the brooch belongs to the Dorgeshuun goblin tribe, as it bears the symbol of the lost tribe.
After quest completion, the brooch can be given to Mistag in exchange for a mining helmet. Exchanging this brooch for a mining helmet is a requirement to obtain the master quest cape.