The relative scratch resistance of minerals is quantified using a defined ordinal scale, commonly accessed in digital document format. This resource outlines ten minerals, each assigned a numerical value based on its ability to scratch those with lower values. For example, a mineral that scratches apatite and is scratched by orthoclase is assigned a hardness between 5 and 6 on this scale.
This standardized measure is invaluable in geology, materials science, and gemology. It provides a simple, field-expedient method for mineral identification and aids in assessing the durability of materials. Its historical significance lies in its development as one of the earliest methods for characterizing material properties, forming a foundation for more advanced hardness testing techniques.