Rosiwal scale

The Rosiwal scale attempts to give more quantitative values of scratch hardness, unlike the Mohs scale which is a qualitative measurement with relative values.

The hardness is calculated by finding the volume of removed material, but this measurement can be difficult and must sample a large enough number of grain in order to have statistical significance.

[2] Measures the scratch hardness of a mineral expressed on a quantitative scale.

These measurements must be performed in a laboratory, since the surfaces must be flat and smooth.

The base value of the Rosiwal scale is defined as corundum set to 1000 (unitless).