Underground Hallow

The Underground Hallow is a Hardmode Biome, being one of the biomes that spawns when the Wall of Flesh is defeated. It is the underground version of the surface-level Hallow, and appears at and below the cavern layer. It operates similarly to surface Hallow, being comprised of Pearlstone and Pearlsand; though it spawns different enemies, along with Crystal Shards, a common Hardmode crafting material. Underground Hallow spreads just like surface Hallow, and similarly can not spread to Corruption (nor to Underground Corruption).

Underground Hallow does not suppress the spawn of other underground and cavern enemies.

All enemies killed in the Underground Hallow have a chance to drop a Soul of Light.

''Note: Most characteristics of surface Hallow apply to the Underground Hallow, with the exception of the enemies that spawn. See The Hallow for more extensive information.''

Note: We're not sure iff this is limited to the Underground Hallow, but since the 1.3 update, enemies have a small chance of spawning a golden circle that drops around 9 to 11 gold.