The hardest natural material known to man is diamond. Formed deep within the Earth's mantle under extreme pressure and temperature, diamonds are renowned for their exceptional hardness, which makes them highly valued not just for their beauty in jewelry but also for industrial applications. Their hardness allows diamonds to be used in cutting, grinding, and drilling tools. Each diamond's structure consists of a unique arrangement of carbon atoms in a crystal lattice, giving them their remarkable properties. As a result, diamonds stand as a symbol of wealth, durability, and beauty in various cultures around the world.