Rosiwal scale Rosiwal scale The Rosiwal scale is a hardness scale, with its name given in memory of the Austrian geologist August Karl Rosiwal. The Rosiwal scale bases its measure on absolute values, unlike the Mohs scale whose values are relative values, its interest is relegated to the amateur or an approach that makes it useful in the research field ('in situ'). The Rosiwal method (also called Delesse and Rosiwal) is basically a method of petrographic analysis and led to the development of the stereograph. Measures in an absolute scale the hardness of minerals expressed as abrasion's resistance, measured at laboratory, starting
Indentation hardness can be applied with heavier loads as macroindentation tests: In microindentation testing, the hardness number is based on measurements made of the indent formed in the surface of the test specimen. The hardness number is based on the applied force divided by the surface area of the indent itself, giving hardness units in kgf/mm². Microindentation hardness testing can be done using Vickers as well as Knoop indenters. For the Vickers test, both the diagonals are measured and the average value is used to compute the Vickers pyramid number. In the Knoop test, only the longer diagonal is measured, and the