The cat's eye" effect, or chatoyancy, is a fascinating optical phenomenon. It happens when a band of reflected light appears across the surface of a material, resembling the slit pupil of a cat's eye. This effect is created by microscopic, parallel, needle-like inclusions or fibers within the material. When light hits these tiny structures, it reflects in a concentrated line. As you move the bead or the light source, this band of light appears to glide across the surface, giving it that distinct, mesmerizing quality. These are Teardrop shaped 39mm pendants.