Indentation hardness
Hardness measurements quantify the resistance of a material to plastic deformation. Indentation hardness tests compose the majority of processes used to determine material hardness, and can be divided into two classes: "microindentation" and "macroindentation" tests. Microindentation tests typically have forces less than . Hardness, however, cannot be considered to be a fundamental material property. Classical hardness testing usually creates a number which can be used to provide a relative idea of material properties. As such, hardness can only offer a comparative idea of the material's resistance to plastic deformation since different hardness techniques have different scales.
Thickness (geology)
Thickness is measured at right angles to the surface of the seam or bed and thus independently of its spatial orientation. The concept of thickness came originally from mining language, where it was used mainly to indicate the workability of seams. It has since become an established term in earth science, for example in geology, for the depth of sedimentary rocks, in hydrogeology for the vertical extent of groundwater – i.e. the distance from the base of the groundwater layer to its surface – or in soil science for the vertical extent of soil horizons.