Diamonds have the following unique characteristics: 1. Extremely high hardness: Diamond is the hardest substance in nature, second only to synthetic materials such as hard diamond and nanowires. 2. Strong wear resistance: the surface of the diamond is extremely flat and smooth, and it is not easy to be worn and scratched. 3. High refractive index: The high refractive index of diamonds makes them shine and become the first choice for high-end jewelry. 4. High thermal conductivity: The high thermal conductivity of diamond makes it have excellent heat dissipation performance and is widely used in the electronic field. 5. Easy to form single crystal: Diamond is easy to form single crystal and is an important material for manufacturing high-quality tools and semiconductor materials. These are the unique characteristics of diamonds.