Friedrich Mohs was a German mineralogist best known for creating the Mohs scale of mineral hardness in 1812. This scale ranks minerals based on their ability to scratch one another, providing a simple way to identify and compare the hardness of various minerals. Mohs' scale ranges from 1 to 10, with talc at the softest end and diamond at the hardest. His work laid the foundation for modern mineralogy and remains a fundamental tool in geology and materials science today.