This 6000 grit water stone made by Imanishi is excellent for polishing your blade. It is a single grit ceramic water stone that will last a lifetime.

The 6000 Grit Deluxe Finish Stone is fired from 6000 grit abrasive mixed with a clay binder and no plastic binders additives.

It is a water stone and should be kept wet during use and allowed to dry between uses. As you sharpen, a slurry is formed by the mixture of clay, water and steel. This slurry is an integral part of the sharpening process.

Although you can certainly move to a finer grit stone from this one, this 6000 grit stone is excellent for polishing.

This stone is free standing and so you can use all sides for sharpening. 

Size:
Length: 8-3/8-in (210 mm)
Width: 2-13/16 (73 mm)
Thickness: 1-in (23 mm)