This Hard (Fine) Arkansas sharpening stone is 4 inches long by 2 inches wide by 1/2 inch thick Hard Arkansas (Fine) stones are used to establish and maintain a keen edge on a wide range of edge tools Color can range from Grey, White, Black/Grey, Grey/Pink, Black/ White, White or White/ Pink This genuine Arkansas stone is 100% quarried in the Ouachita Mountains of Central Arkansas Come fitted in a wooded box to protect when not in use. This genuine Arkansas Novaculite Hard (Fine) stone is used to establish and maintain the keen edge on cutting tools. Hard stones produce an edge comparable to 800-1000 grit. Color of Hard stones may range from Grey, White, Black/Grey, Grey/Pink, Black/ White, White or White/ Pink, or a combination of these colors in a single stone. These genuine Arkansas Novaculite stones were quarried in the Ouachita Mountains of central Arkansas. They are highly sought after worldwide for their superior ability to put a keen edge on knives and woodworking tools, as well as to put surgical quality edges on a wide range of instruments. Arkansas stones produce these fine edges with less wear that manmade stones. Arkansas stones are classified as Novaculite, which is an extremely hard and fine-grained mineral containing almost pure silica. These stones are classified in 4 grades and progress from Soft to Hard to Translucent and finally to Surgical Black. Each grade is based on the specify gravity or density of the mineral and not the grit or particle size. The grades with more dense or tightly packed particles will produce a finer or sharper edge. In addition, stone grades are not determined by color, as color alone will not differentiate the hardness of different stone grades. Arkansas stones are a natural product, and each stone is different and each grade may contain any of the following colors: black, blue-black, charcoal, grey, white, multi-color, brown, pink or red, or a combination of these colors in a single stone. These stones come fitted in a wooded box to protect them when not in use. All Arkansas stones work best with a coating of light mineral honing oil to suspend metal particles and prevent clogging.