If a diamond is the hardest known substance , what is used to cut diamonds?

When considering the properties of materials, hardness refers to a substance's resistance to scratching, abrasion, or indentation. Diamonds are renowned for being the hardest known natural material, a characteristic stemming from their unique atomic structure. Each carbon atom in a diamond is covalently bonded to four other carbon atoms in a tetrahedral lattice, creating an incredibly strong and rigid network (Review) that is exceptionally difficult to break or disrupt. This supreme hardness is why diamonds sit at the very top of the Mohs scale of mineral hardness, scoring a perfect 10.

Given this unparalleled hardness, the only material capable of effectively cutting or shaping a diamond is another diamond. The principle is simple: a softer material cannot abrade a harder one. Therefore, specialized tools equipped with diamond tips or edges are employed for this intricate task. These tools can be made from natural diamonds, or more commonly, from synthetic diamonds, which possess the same extreme hardness and are more readily available for industrial applications.

The process of cutting diamonds is a highly skilled craft, essential for transforming rough stones into the brilliant gems we admire. Industrial applications also heavily rely on diamonds for their abrasive qualities, using them in grinding wheels, drills, and polishing compounds for various hard materials beyond just other diamonds. This remarkable property makes diamonds indispensable not only in jewelry but also in numerous technological and manufacturing processes where precision and durability are paramount.