Brilliant alchemist's amulet fragments were an uncommon reward from Treasure Hunter during the January 2015 Alchemist's Amulet promotion. They later returned on 11 December 2015 for one day during the Christmas Advent Calendar promotion and one fragment was gifted to players. During June 2016, they returned permanently as a rare reward. Also making another one day comeback on 24 August 2017 as a reward from the Summer Beach Party's treasure map event. You were able to collect two on this day from the map. Also possible to collect later on from the map by paying a bond which unlocks all the rewards of the map.
Combining 10 brilliant alchemist's amulet fragments will create a Brilliant alchemist's amulet (charged) and provide an amount of coins depending on the player's total level. Combining less than 10 fragments will create an uncharged brilliant alchemist's amulet and fewer coins.