Mineralogy
"Hardness" is determined by comparison with other minerals. In the Mohs scale, a standard set of minerals are numbered in order of increasing hardness from 1 (talc) to 10 (diamond). A harder mineral will scratch a softer, so an unknown mineral can be placed in this scale by which minerals it scratches and which scratch it. A few minerals such as calcite and kyanite have a hardness that depends significantly on direction. Hardness can also be measured on an absolute scale using a sclerometer; compared to the absolute scale, the Mohs scale is nonlinear.
Hardiness (psychological)
There are several instrument developed to measure hardiness, the most frequently used being the Personal Views Survey, the Dispositional Resilience Scale, and the Cognitive Hardiness Scale. In addition to these, other scales based on hardiness theory have been designed to measure the construct in specific contexts and in special populations, such as for example parental grief and among the chronically ill.