Alfred Mohs

Alfred Mohs was a German mineralogist best known for developing the Mohs scale of mineral hardness. This scale ranks minerals from 1 to 10 based on their ability to scratch or be scratched by other substances. Talc is rated 1 (softest) and diamond is 10 (hardest). The scale helps geologists identify minerals in the field and laboratory quickly and effectively. Unlike other measures of hardness, the Mohs scale is qualitative—it's based on relative comparison rather than precise measurements—making it a practical tool for mineral identification.