physical chemistry - How does an infinitely hard tip scratch an amorphous brittle material when it slides along it?

I know infinitely hard materials don't actually exist but sometimes the tip is so much harder than the substance it's scratching that it can be treated like one. Suppose a sharp diamond tip is made to look like the vertex of a tetrahedron by fracturing it along its cleavage planes and then it slides along a surface of glass that's nanosmooth. What is the nature of the scratch that was made and why does it come out that way? Is the scratch a fractal of cracks? If so, what type of fractal is it? What power of the scratching speed and total pressing force does the depth of the scratch vary as? Why does the scratch come out as that type of fractal? When the tip scratches the glass, does the scratch end up so deep that a nanosmooth rod of glass the thickness of the scratch could support a much bigger force of tension than the pressing force of the tip because the material gets weakened as a result of beginning to get scratched enabling it to get scratched even deeper? Is it the case that molecular theory is needed to predict how the scratch would come out and that if atoms were half the size with a quarter the strength of their bonds, glass etched nanosmooth would still have extremely close to the same tensile strength but the diamond tip moving at the same speed with the same total pressing force would make a deeper scratch?