Soul Soil

Soul soil is a block naturally found only in the soul sand valley.

Natural generation
Soul soil generates naturally in the soul sand valley biome.

Obtaining
Soul soil drops as an item when broken with any tool or by hand, but a shovel is the fastest way to break it.

Usage
Can be used as a method of long distance travel with the Soul Speed enchantment

Fire
Fire lit on soul soil becomes soul fire.

Withers
4 blocks of soul soil (or soul sand) are used in the construction of a wither.

Trivia

 * Unlike soul sand, soul soil does not slow mobs down.