The Arkansas Stone is famous the world over for its unique capacity to impart an extremely fine finish to a cutting edge. No other oilstone can approach the sharpening characteristics of this beautiful creation of nature. Arkansas Stone is geologically classified as a Novaculite. Novaculites are very hard, fine-grained siliceous rock, probably of sedimentary origin. They are nearly pure Silica and can be many times harder than marble.
The harder formations of Arkansas stone range from black to pure white through whites containing various shades of yellow, red and gray. True Hard Arkansas is glass like and translucent in appearance. This stone will produce a mirror finish on cutting edges. Soft Arkansas stone is opaque and milky white in color and can contain shades of yellow, red and gray. Its structure is more open and will develop a honed cutting edge. Still softer, Washita Arkansas stone is a good deal coarser than Soft Arkansas. Also opaque, it has an attractive grainy mixture or white, red and gray colors. It produces a good sharp edge rather than a fine finish. Arkansas Sharpening Stones will not cut as rapidly or aggressively as man-made stones or diamond sharpening devices. For well maintained cutlery and knives this is an advantage. You get a superior cutting edge with minimum wear on your cutlery.
The only known Novaculite deposits suitable for sharpening stones are in the Ouachita Mountains, not far from Hot Springs, Arkansas. Novaculite deposits are located by prospectors who search for leads in outcroppings on the side walls of cliffs and mountains. A lead may run in any direction: horizontally, obliquely or vertically. In following it, there is no way to foretell what quantity or quality of rock will be encountered. When a vein is struck, which is apparently suitable, it is generally a solid mass of extremely hard and brittle rock with no natural lines of cleavage. Quarrying involves blasting with black powder. Because of its brittle nature, light charges must be used. Quarried stone is cut with diamond saws and shaped into many forms using hand and mechanical production procedures.