When light passes through a prism, colors are refracted differently to produce a rainbow effect, the same principle as for the formation of rainbows in nature. Natural tooth slices measuring 1.0-0.3mm in thickness were produced. Due to cross-polarization, light penetrating enamel crystallites of natural teeth cause iridescence. Image 1: Slices of rear molars. Image 2: When the angle of incidence is low, there is star-like refraction. Image 3: Using video editing software to create a negative image effect, layered structures and optical properties of the teeth and enamel are emphasized.