If you break quartz to learn if it splits smoothly in a certain direction, what physical property are you testing?

The physical property that are being tested, when you break quartz to learn if it splits smoothly in a certain direction is called conchoidal fracture. I hope this is the answer you were looking for. This kind of fracture is actually a curved breakage that resembles the concentric ripples that can be seen in muscle cells.

Its decreasing because of illnesses