The hardest material found in nature is diamond. Diamonds are crystalline forms of carbon where the carbon atoms are arranged in a specific lattice structure, giving them unmatched hardness and durability. They form under high-pressure, high-temperature conditions deep within the Earth's mantle and are brought to the surface through volcanic eruptions. Beyond their physical properties, diamonds are highly valued for their aesthetic qualities and are commonly used in jewelry. Diamonds also have practical applications, particularly in cutting, grinding, and drilling tools due to their ability to cut through or abrade other materials.