Soul Sand

Soul sand is a block found primarily in the Nether that slows down entities walking on it unless they are wearing Soul Speed boots. It can also be used to grow Nether wart, create soul fire, and make upward bubble columns.

Soul sand can be mined with any tool or by hand, but shovels are the quickest.

Soul sand generates most abundantly in soul sand valleys, where it and soul soil make up the surface terrain. It is also found below Y=34 in the Nether wastes along the shores of lava seas, generally in four-block-deep layers.