Mohs scale of mineral hardness finding the hardest material that the given material can scratch, or the softest material that can scratch the given material. For example, if some material is scratched by apatite but not by fluorite, its hardness on the Mohs scale would fall between 4 and 5. "Scratching" a material for the purposes of the Mohs scale means creating non-elastic dislocations visible to the naked eye. Frequently, materials that are lower on the Mohs scale can create microscopic, non-elastic dislocations on materials that have a higher Mohs number. While these microscopic dislocations are permanent and sometimes detrimental to the harder material's structural
Leeb rebound hardness test a Brinell indentation on the same material is ~3 mm (hardness value ~400 HBW 10/3000), with a standard-compliant measuring time of ~15 seconds plus the time for measuring the indentation. Depending on the probe (“impact device”) and indenter (“impact body”) types that vary by geometry, size, weight, material and spring force, diverse impact devices and hardness units are distinguished, e.g.: Generally, impact device types are optimized for certain application fields. This is similar to using various indenter geometries and test loads in Rockwell (e.g. HRA, HRB, HRC), Brinell and Vickers. Leeb hardness results in HL are often converted to the