Pearlstone Block

Pearlstone is a white colored Ebonstone analog from The Hallow. Placing 200 of these blocks causes the regular ground to transform into The Hallow or Underground Hallow biome, which will spread and attract their 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.