Ores

Overworld
Kelp Ore: Smelts into kelp

Petrified Wood: Smelts into wood

Experience Ore: Drops experience

Random Ore: Drops a random resource

Potion Ore: Splashes a random potion

Health Ore: Can be used to make Medkits and Golden Medkits

Liquid Ore: Can be used to make armor

Nether
Bone Ore: Drops bones and bonemeal

Fire Ore: Used to make Fire Crystals

Explosive Ore: Explodes when broken and used to make Unstable TNT

End
Hardened End Stone: Drops a random valuable item when broken with a diamond pickaxe

Pearl Fragment: Used to make better ender pearls

Corrupted Ore: Used to make armor and upgrade swords

Other
Ice Ore: Used to make the Ice Helmet and Ice Boots. Found in the Overworld and the End.