The Spyderco Slip-Stone is idea for sharpening curved blades, woodworking tools, plane irons and sophisticated edge shapes. When viewed in profile, slip stones are teardrop shaped. They hone flat, concave, and convex edges and bring slant-edge and straight chisels to their sharpened best. Spyderco’s fine grit ceramic slip stones are made from Alumina Ceramic through a process in which a bonding agent is combined with Alumina particles that are actually synthetic sapphires. The stone is formed into a slip teardrop and kiln fired to 3000 degrees F (1649°C). Alumina ceramic stones measure 9 on the Mohs hardness scale (out of 10) and don’t require lubricants like oil or water for use. Fine grit stones tighten and smooth the cutting edge’s scratch pattern for an keen, hair-popping edge. Spyderco’s slip stone is 2 -Inch X 4 -Inch and is thin and light enough for hand-held use. For tabletop sharpening, place the stone on top of its suede carrying case for slip-free use. To clean, wash in fresh water and scrub with powdered abrasive cleaner and a scouring pad. Rinse and air dry.