How to Perform the Test

1. Select a fresh surface
Step 1

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)
step 2

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.


This was a very simple demo provided for a presentation at the 1994 AAIM conference