Blight Rot is the corrupted stone that makes up Blight areas. It is a sturdy building material that can be crafted into Blight Rot Slabs and Blight Rot Stairs, or combined with Aervines to make Grassy Blight Rot. It must be mined with a pickaxe to drop itself.
Blight Rot generates naturally throughout Blight areas. It must be mined with a pickaxe to drop itself; breaking it by hand or with the wrong tool yields nothing.