Crimstone Wall

Crimstone Walls are naturally-occurring background walls found in the Crimson chasms. They can be destroyed with the Hammer, but can not be picked up as item.

Crimstone Walls cannot be crafted by the player, but they can be converted from Stone Walls by using Red Solution sprayed with the Clentaminator. As the Clentaminator affects a rather large area, creating areas of localized Crimstone Walls without converting blocks and other wall parts may be difficult.

Trivia
While it is named Crimstone Wall, it resembles Crimtane Ore.