Niter is a critical component in the creation of Cryotheum Dust and Aerotheum Dust, and their corresponding fluids. The material can also be used together with Sulfur to create Gunpowder. Lastly, it can be used to craft Phyto-Gro for use in Phytogenic Insolators from Thermal Expansion.
Since Niter is essentially saltpeter, it may feel more logical to call the material 'Saltpeter Dust'. The reason behind the name 'Niter' is that it is actually a more accurate term for this material; 'Niter' is defined as the mineral form of saltpeter.