The Mohs Hardness Scale is a system used to rank the hardness of minerals based on their ability to scratch one another. Developed by Friedrich Mohs in 1812, the scale consists of ten minerals, each assigned a value from 1 to 10. For example, talc is the softest mineral at 1, while diamond is the hardest at 10. Each mineral can scratch those with lower numbers and can be scratched by those with higher numbers. This scale helps geologists and gemologists identify minerals and understand their properties, making it a fundamental tool in the study of geology.