Mohs Hardness is a scale used to measure the hardness of minerals. Developed by Friedrich Mohs in 1812, it ranks minerals from 1 to 10 based on their ability to scratch one another. For example, talc is the softest mineral at 1, while diamond is the hardest at 10. Each mineral on the scale can scratch those below it and can be scratched by those above it. This simple system helps geologists and gemologists identify minerals and understand their properties. The scale includes common minerals like calcite and quartz, making it a practical tool in geology.