Produce the keenest edges on laboratory blades, surgical instruments, engravers and die makers tools, and pocket knives with the Norton Hard Arkansas Stone Precision Benchstone. These Hard Arkansas stones are made of novaculite and are very dense fine grained natural stones, ideal for creating the sharpest, most razor-like edges and precise, polished finishes. Use these stones with oil to increase the sharpening action and minimize the clogging of the stones' surface.