Mohshårdhet

Mohshårdhet is a qualitative scale ranking the scratch resistance of various minerals. Developed by German geologist Friedrich Mohs in 1812, it is not a linear scale but rather assigns numbers from 1 to 10, with 10 being the hardest. A mineral with a higher Mohs number can scratch a mineral with a lower Mohs number. For example, diamond, with a Mohs hardness of 10, can scratch any other mineral on the scale. Conversely, talc, with a Mohs hardness of 1, can be easily scratched by any other mineral.

The scale is based on the ability of one mineral to abrade or scratch another. The standard set of minerals used for comparison are: 1. Talc, 2. Gypsum, 3. Calcite, 4. Fluorite, 5. Apatite, 6. Orthoclase Feldspar, 7. Quartz, 8. Topaz, 9. Corundum, and 10. Diamond. Practical applications often use common objects to estimate hardness. For instance, a fingernail has a hardness of around 2.5, a copper coin around 3.5, and a steel knife blade around 5.5. Geologists and gemologists use the Mohs scale to help identify unknown minerals. While it provides a simple and useful measure of relative hardness, it is important to note that the difference in hardness between successive numbers on the scale is not uniform. For instance, the difference in actual hardness between diamond and corundum is much greater than the difference between gypsum and talc.