What is a 'pumice stone'?

What is a 'pumice stone'?

A pumice stone is shaped like a bar of soap, with the rounded sides. A pumice stone normally has two sides; one side is coarser than the other side. The coarse side is used to break down the callous, and the smooth side is used to go back over it so that the skin is nice and smooth. Since the coarse side is going to break up the callous, it's going to feel rough, so you need the smooth side of the pumice to even out the skin. A pumice stone is used for reducing callous buildup.