Gemstones that exhibit a cat's eye effect

When exposed to light, a cat's eye gemstone reveals a single ray of light in the middle, just like a cat's eye. This phenomenon is called chatoyancy or cat's eye effect, and is said to be caused by the inclusion of tube-shaped inclusions inside. It is often cut into a dome-shaped cabochon to make the cat's eye effect more visible.

Karatz GemMagazine
" Cat's Eye Jewel "