Fiber Optics
Fiber Optics is a cat's eye chatoyant man-made glass material.
Fiber Optics is the thin fibers used in telephone technology, millions of them have been meshed together to form a glass material that cuts easily and takes a great polish!
When cut the material "reflects" an inner light that moves when you move your piece. The light appears as a slit in the center, hence the term "Cat's Eye".