The hardest known mineral is diamond, which is renowned for its exceptional hardness and durability. Formed deep within the Earth's mantle under high pressure and temperature, diamonds are composed entirely of carbon atoms arranged in a crystal lattice structure. This unique arrangement not only gives diamonds their strength but also contributes to their brilliant light dispersion, making them highly desirable in jewelry. Diamonds are not only valued in adornments but also have industrial applications, such as cutting, grinding, and drilling tools. Their rarity, along with their captivating beauty, has made diamonds a symbol of luxury and romance.