Glarial's pebble is an item used in the Waterfall Quest and Roving Elves. It is given to the player by Golrie as a reward for freeing him from the dungeon under the Tree Gnome Village. If you lose this pebble you can go back to Golrie to obtain another. A key is required to enter his room. He will take the key if you have it, but he will give you the pebble even if you drop the key.
It can also be re-obtained at May's Quest Caravan after putting 150 quest points into the Hub Track.
The pebble is used to gain access to the Glarial's Tomb dungeon near the Baxtorian Falls. Before being allowed to enter the dungeon, the player must bank all weapons, armour and runes.