How does a scientist test a mineral hardness?

Answer 1

By hardening then cooling

Answer 2

The hardness of materials is a function of their elastic modulus. As such a number of tests are used to measure hardness.

Relative hardness can be assessed by the scratch test where one material or mineral is used to scratch another. As such, the rock that manages to scratch the other is harder, while the one that is scratched is softer. This comparative or relative hardness method is the basis of the Mohs hardness scale.

More quantitative methods of assessing the hardness of materials and rocks are based on the height of rebound of a hammer of known mass allowed to fall from a fixed height (which imparts a known energy into the material), where the height to which it rebounds is dependant on the properties of the rock. As such, the higher the rebound, the larger the elastic modulus of the rock and the harder the rock. Two examples of tests which use this methodology are the Schmidt hammer test and the Shore scleroscope test.

Another common method used to measure the hardness of materials is to assess the depth of indentation of a tool of fixed dimensions at a specified applied load into the material of interest, where the larger the size of indentation, the softer the material. However this methodology is more commonly used for testing metals than rocks.

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Answer 3

By doing a hardness test. The good ones use a calibration ball or point pressed into the subject material with a known force. How big the dent is tell you how hard the material is.

Answer 4

You can heat steel in a fire. That will take the 'temper' or hardness out, in most cases.

Answer 5

they use different things to try and scratch the surface of it. like they could use their fingernail and if it scratches its a level 1 in hardness if not you try the next thing.