Pulverizer (Thermal Expansion 5) - Official Feed The Beast ...
Stone can be ground into Cobblestone, Cobblestone into Gravel, and Gravel into Sand. Sandstone can also be processed into Sand. Processing Gravel has a 15% chance to yield Flint as a secondary product, and processing Sandstone has a 40% chance to produce Niter. Netherrack is ground into Gravel, but is a good way to obtain Sulfur at a 15% chance.