The hardest mineral known on Earth is diamond. Diamonds are composed of carbon atoms arranged in a crystal lattice structure, which grants them exceptional hardness and durability. Due to their unique properties, diamonds score a perfect 10 on the Mohs scale of mineral hardness, making them particularly resistant to scratching. This characteristic makes diamonds highly sought after not only for jewelry but also for industrial applications, such as cutting and grinding tools. The extraordinary brilliance and optical qualities of diamonds, along with their hardness, have contributed to their status as symbols of luxury and value across cultures.