The term "Devil's Eye" can refer to various natural phenomena, including a specific type of gemstone known for its unique appearance. Often associated with the cat's eye effect, this gemstone displays a narrow band of light that moves across its surface, resembling a cat's pupil. It is popular in jewelry and is believed to have protective properties. In some cultures, "Devil's Eye" also refers to a symbol used to ward off evil spirits. This symbol, often depicted as an eye, is thought to provide protection against negative energies and is commonly found in amulets and jewelry.