Naniwa Professional Stone #600

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.
#600 is a really nice stone to start on if your egg is either chopped or very very dull.

Dimensions: L: 21 cm W: 7 cm H: 2 cm
Material: White aluminum oxide (WA)