Lignite

From DwarfFortressWiki

Lignite

* * * * * * * ● = = = * * * ● ● = = = * * ● ● ● ● = = * ● ● ● ● ● ● =
Uses
Create 2 coke at smelter Masonry Stone crafting Construction
Location
Sedimentary layers Found as veins
Properties
Can ignite Economic stone Material value 1
Wikipedia article

One of the two mineral sources of fuel. Produces 2 coke for each unit of coal processed at the smelter. However, this processing consumes a unit of fuel. This leaves a net gain of 1 fuel. If lignite is processed at a magma smelter, it produces 2 fuel.