Cat’s eye gemstones are distinguished by their special optical phenomena, known as chatoyancy, derived from the French saying for the eye of the cat. This effect resembles the slit eye of a cat and is caused by the reflection of light by parallel fibers, needles or channels in the gemstone. The most famous and valuable cat’s eye gemstone is chrysoberyl cat’s eye. When the term cat’s eye is used alone in the gem trade, it always refers to chrysoberyl cat’s eye. This stone is commonly known to bring wealth and prosperity and/or help people regain lost wealth. Chrysoberyl cat’s eye is found in Sri Lanka, Brazil, India, China and Zimbabwe. Some other notable sources include India, Pakistan, Russia, Tanzania, Madagascar and the United States.