In this example, we use a sharp quartz crystal (H=7)
2. Hold the sample and attempt to scratch it with the point of an object of known hardness.
In this example, we use a sharp quartz crystal (H=7)
3. Press the object firmly but lightly against the unknown sample.
4. If the test object is harder, you should see and feel a definite "bite" into the sample.
5. Inspect for an etched line.
In this case, we notice a deep scratch in the sample, which indicates it's hardness is less than 7
6. Repeat several times, always with a sharp point and a fresh surface.
