From Guild Wars 2 Wiki
Jewel Shards are bundles which drop from King Toad after striking his amulet. They are used to make him vulnerable to attacks if thrown into his mouth.
|1||Throw||1||Throw your jewel shard at your foe.|
- Make sure to target Kong Toad's head before throwing.
- These can also be used on the toads sitting on the walls of the area. They affect an area and cause 25 damage.