Combination stone of diamond and ceramic, the knife sharpening stone.

Fällkniven Diamond / Ceramic Sharpening Stone DC3 consists of a fine diamond stone (25 microns) and a ceramic stone made of synthetic sapphire. The diamond side is used for basic sharpening, while the ceramic side is used for fine sharpening. These materials have the advantage that they do not lose their flat surface over time. This is a great advantage if you want to sharpen knives. As diamond/ceramic is the hardest known material, you can sharpen even the hardest types of steel, even powder steel, with this whetstone. The stone can be used dry and should only be cleaned occasionally with warm water and mild detergent. The whetstone may feel a little rough at first, but will become smoother after a while.