Dynamite

Dynamite is the strongest of all thrown explosives. When thrown, it explodes after five seconds, destroying a great area. Dynamite can destroy almost any block, exceptions being Dungeon Bricks, Cobalt, Mythril, Adamantite, Hellstone (before defeating Wall of Flesh), Demon Altars, and any type of Chest (including Barrels and Trash Cans). At point blank range, dynamite causes a total of 250 damage to mobs and 500 to the player. The reason for this is that dynamite is thrown by the player, so it follows the PvP rule of player attacks doing double damage to other players.

Dynamite may be found in chests or bought from the Demolitionist.

Mining meteorites
Dynamite works exceptionally well for mining meteorites. 1-3 dynamite strategically placed will mine 80-90%, if not all, of the meteorite. This will instantly stop more Meteor heads from spawning and allow you to safely mine the remaining ore with your pickaxe.

Blast mechanics
Dynamite has a blast radius of 14 ft (7 blocks).

Blast power is not affected by intervening material, it will destroy every block and wall it can destroy within a 14 ft radius.

For instance, if lit dynamite is surrounded by Dungeon Bricks (which cannot be destroyed), it will still destroy other destructable blocks outside of the Dungeon bricks but inside the blast radius.