Scratch hardness (MOH’S Scale Ratings)
The relative hardness of glazed tile is an important issue that should be addressed when selecting a tile. The test is performed by scratching the surface of the tile with different minerals and subjectively assigning a “MOH’s Scale Hardness” number to the glaze.
The softest mineral used is talc (“l rating), the hardest is a diamond (“10” rating). Other minerals of varying hardness provide Moh’s Scale Hardness values of 5 to 7 and are suitable for most residential floor applications. A value of 7 or greater is recommended for commercial applications.