Terraria Tremor Wikia

Sea Fragments have a small chance to drop from all underwater mobs (Blue Jellyfishes have a slightly higher chance to drop them).Sometimes they drop up to 2 from a single mob.

They are used in these recipes:

Blue Sakura (Magic Weapon) (15 Wood,5 Sea Fragments)

Crab Staff (Summon Weapon) (16 Corals,5 Sea Fragments,2 Seashells,8 Wood)

Cyclone (Magic Weapon) (1 Ancient Technology,30 Nebula Fragments,25 Sea Fragments)

Earthquake (Magic Weapon) (Spell Tome,25 Mud Blocks,14 Earth Fragments,10 Sea Fragments)

Key of Ocean (1 Golden Key,12 Sea Fragments)

Murasamu (Melee Weapon) (Muramasa,16 Sea Fragments)

Ocean Bate (Ranged Weapon) (25 Sea Fragments,20 Corals,8 Shark Fins,25 Concentrated Ether)

Piranha Staff (Magic Weapon) (Goldfish Staff,10 Sea Fragments,8 Gold/Platinum Bars,6 Rubies)

Rain Staff (12 Wood,9 Rain Clouds,10 Sea Fragments)

Sorcerer Focus (Mage Ability Boosting Accessory) (Sorcerer Spark,1 Sea Fragment,16 Sapphires)

Storm Jelly (Storm Jellyfish summoner) (25 Gel,12 Sea Fragments,15 Glowsticks,3 Seashells)

True Terra Blade (Melee Weapon) (Terra Blade,25 Nightmare Bars,30 Sea,Earth,Fire and Air Fragments)

Water Dead Shot (Ranged Weapon) (8 Sea Fragments,10 Sapphires,6 Gold/Platinum Bars)