Stoneware scratches more easily than porcelain. Porcelain is comparatively difficult to scratch, as it is the hardest man-made material aside from industrial diamonds.
Porcelain is a non-porous material made from white clay heated to 2,300 degrees Fahrenheit. It may look thinner and more delicate than stoneware, but it is much less susceptible to marks. The primary way that porcelain does get scratched is when it is stacked on top of other pieces of porcelain. The unglazed base of a porcelain piece of dinnerware can scratch another piece of porcelain.
Stoneware, on the other hand, is made of a light-colored clay heated to 2,200 degrees. It is thicker and more opaque than porcelain. Although it is heavier, it commonly gets scratches from everyday use. The hard glazes used by stoneware manufacturers are easily scratched by metal utensils. Although stoneware looks like it has a smooth surface, it is actually made up of peaks and valleys that the eye cannot perceive. Small particles of metal get stuck in these ridges to produce the scratches.
Mass-market cleaners are made to help consumers remove such scratches from their porcelain or stoneware products. All the removal process requires is a wet cloth, some appropriate cleaner and a bit of gentle scrubbing over the mark.