Stonedust? Decomposed Granite?
In Massachusetts, the material called "stone dust" is effectively the remains of granite pieces after they go through the crusher to be made into crushed stone for highway base. As such, stonedust includes a relatively high percentage of silt sized material, about 1/3 sand sized material, and the remainder is typically small gravel size. It works well for path material, it hardens when it gets wet, however it is relatively impervious, so do not use it if you need good drainage. It is also prone to frost heave, which is not a problem if you use two inches on top of gravel, but would definitely be a problem if you used it as pavement base.