Coal is a material added by vanilla Minecraft. Thermal Foundation adds a single item made of this material: Pulverized Coal.
Coal is most commonly used as a basic solid fuel. The material can also be processed in a Pulverizer to produce Pulverized Coal and possibly Sulfur. Pulverized Coal can be used as an ingredient to craft Gunpowder or Pyrotheum Dust. It can also be molten down in a Magma Crucible to produce Liquifacted Coal.