Naniwa's Professional sharpening stone is absolutely sublime in terms of quality, ability and appearance. They make them in a material called White aluminum oxide, which is an incredibly hard material, which gives a lasting surface on the stone.
#2000 is insanely effective at giving a sort of medium polish. So between, for example, #600 and #10000
Dimensions: L: 21 cm W: 7 cm H: 2 cm
Material: White aluminum oxide