The Hard Arkansas stone is made of a stone called novaculite. This stone, quarried in the Ouachita Mountains of Arkansas and Oklahoma, is almost pure silica which makes a great surface for sharpening knives and tools. The Hard Arkansas stone is finer than the Soft Arkansas stone so it leaves a finer edge. Because this is a natural stone, the color of the stone varies, but it is usually white. The handsome wooden box keeps the stone safe when not in use. The Hard Arkansas stone is available in 3 sizes to fit your needs. The 4" x 2" x 1" is a small economical stone that is best used only on smaller knives and tools. The 6" x 2" x 1" is a medium sized stone that is popular due to the good size and value. If you do a lot of sharpening, you’ll appreciate the large 8" x 2" x 1" stone; its generous size allows for longer strokes to speed up the sharpening process.