The crystal chime is an item obtained during The Path of Glouphrie quest, where it is made from a crystal chime seed at a singing bowl. A crystal chime must be in a player's inventory when attacking warped terrorbirds or warped tortoises, otherwise they will be immune to all attacks.
In the original RuneScape 3 version, the crystal chime originally had to be used on the warped creatures to begin fighting them, rather than just attacking them with the item present in the inventory.
In RuneScape 3, the crystal chime was originally made from the crystal saw seed. In Old School RuneScape, the chime is made from a separate item.
Partial completion of The Eyes of Glouphrie
Singing bowl