Why do rocks break?

For a structural geologist, strength has a different meaning.

Strength is not the opposite of 'weak' but the amount of stress necessary to induce failure in a given body. So as to say, that a rock that is beneath Earth, pushed to the normal by maximum compressive stress is stronger compared to a rock that is on the surface. If stresses continue still to act on rock's body, it will only absorb it and will make it really hard. Really hard., and the strain rate will become slower until such time, that a failure will be introduced in the form of fractures and flow because the yield stress point has surpassed and the ultimate strength has already overcome.

With the increasing pressure and temperature at depth, the rupture point is the way to go. It is inevitable and so is, failure.

Just like a rock, subjected to different forces acting in and on its body, failures are just accommodating companions along the way. From the first time I realized that I need to tell to my parents that I failed to pass this particular math subject during my sophomore years in college until now, where the feelings of hope for graduation day had already been skipped into passing the board exams because, working for graduation day is not necessary or practical if, you will graduate next year and not this June and that board exam is just seven months away. Those things happen at least I know, and I know some who already slayed the pressure and kept going. I'm not alone.

However, natural as it can be, the intensity of each failure is proportional to its magnitude. An earthquake ruptured for several times locally, would left scars in a form of an increasing fault geometry length evidently by successive fault ruptures.