Ceramic blades are generally sharper than iron blades. This is due to the hardness of ceramic materials, which are typically harder than the steel used in iron blades. Ceramic blades can maintain their sharpness for longer periods, as they are less prone to dulling. According to the Rockwell hardness scale, ceramic materials can achieve hardness ratings of up to 9 on the scale, while high-quality steel used in iron blades typically ranges from 55 to 62 on the same scale. This significant difference in hardness contributes to the superior sharpness of ceramic blades.