Blocks

The environments of Terraria are mostly made up of blocks such as dirt and stone. Most blocks can be collected with a pickaxe. Different blocks may require a higher grade pickaxe to mine. The only blocks that can't be mined with a pickaxe are wood, which requires an axe, as well as Spikes and glass, which require a hammer. Note that glass will shatter when hit, and can't be recollected once placed.

* Tool: The lowest tier of a tool capable for mining that type of block.

** Explosive: The weakest type of explosive capable for mining that type of block. This excludes the grenade, since it doesn't cause any damage to blocks.

*** Demonite Ore can be mined with any type of pickaxe when found above ground level. Below ground level it must be mined with a Gold Pickaxe or better.

Bricks
Bricks are a sub-type of placeable blocks that can be used to build a house or to craft background walls. Pink, blue and green bricks cannot be crafted and are mined from the Dungeon instead. Bricks can be recovered with a pickaxe once placed.

Walls
Walls form the backgrounds of buildings. All walls except for natural dirt walls, mud walls, and Dungeon walls prevent enemies from spawning. A room filled with walls of any type is necessary in order to attract NPCs or to use a bed to set the spawn point. Walls can be knocked down with a hammer.