Pearlstone Block

Pearlstone is a white colored Ebonstone analog from The Hallow, only appearing after defeating the Wall Of Flesh. Placing 100 of these blocks causes the normal ground to transform into The Hallow or Underground Hallow biome, which will spread and attract their specific mobs, such as Pixies, Unicorns, and Gastropods.

At hardmode any hallowed block will turn regular stone blocks that are up to three squares away into Pearlstone.

Used in
Wraiths cannot pass these bricks therefore making pearlstone useful for defending agenst them (tested on Xbox360