Per the manufacturer this is their information regarding their stones: "Arkansas Stones are graded not by grit numbers like other types of sharpening stones, but by their density and hardness. The less dense, or softer the stone, the coarser it is. The more dense, or harder the stone, the finer it is. The coarsest Arkansas Stone we carry is the Soft Arkansas. The Hard Arkansas is in the middle of the Arkansas stones, and the Hard Black and Hard Translucent Arkansas stones are the finest. All grit number equivalencies with Arkansas Stones are approximate of course, but the numbers are usually given as: Soft Arkansas 600-800 grit, Hard Arkansas 800-1000 grit, and Hard Black or Hard Translucent Arkansas 1200+ grit."