The hardest substance found in nature is diamond. Formed under conditions of extreme heat and pressure, diamond is composed of carbon atoms arranged in a crystal lattice structure, which gives it exceptional hardness and durability. Due to these properties, diamonds are not only valued as gemstones in jewelry but are also used in industrial applications such as cutting, grinding, and drilling. Their hardness makes them one of the most sought-after materials in various fields, including technology and manufacturing. Diamonds are often graded based on cut, clarity, color, and carat weight, influencing their market value.